1 <TAXON name="Allosauridae" nickname="Gigantic Predators">
2 <WORD key="1" content="predator, big, large, huge, biggest, carnivore"/>
3 <WORD essay="1" content="carcharodontosaurine allosaurids"/>
5 <CLADE name="Allosauridae" in="Allosaurus" out="Sinraptor" silhouette="carnosauria">
6 <AUTHOR type="sensu" name="Padian, Hutchinson" year="1997"/>
7 <CGENUS name="Acrocanthosaurus" silhouette="acrocanthosaurus"/>
8 <CLADE name="Allosaurinae" in="Allosaurus" out="Carcharodontosaurus, Cryolophosaurus, Monolophosaurus, Sinraptor">
9 <CSYNONYM name="Allosauridae" sensu="Sereno"/>
10 <CGENUS q="1" incertae="1" name="Antrodemus"/>
11 <CGENUS name="Allosaurus"/>
12 <CGENUS name="Saurophaganax"/>
14 <CLADE q="1" name="Carcharodontosaurinae" in="Carcharodontosaurus" out="Allosaurus, Cryolophosaurus, Monolophosaurus, Sinraptor">
15 <CSYNONYM name="Carcharodontosauridae" sensu="Sereno"/>
16 <CGENUS name="Neovenator" q="1"/>
17 <UNNAMED comment="pneumatic"/>
19 <UNNAMED comment="giant">
20 <TIME value="Albian"/>
21 <TIME value="Cenomanian"/>
22 <!--LENGTH value="13"/-->
23 <!--LENGTH value="14"/-->
24 <PLACE name="Argentina"/>
26 <CGENUS q="1" name="Bahariasaurus"/>
27 <CGENUS name="Carcharodontosaurus"/>
28 <CGENUS name="Giganotosaurus"/>
33 <CLADOGRAM alternate="1">
34 <REFER page="Neoceratosauria"/>
37 <P header="Mighty Hunters"> These were large, often huge predators. Some
38 of the carcharodontosaurines are the largest known carnivores ever to walk
39 upon the Earth, even larger than <NOMEN name="Tyrannosaurus rex"/>.</P>
41 <P>A recent find of a group of differently-aged carcharodontosaurines (the
42 genus is yet to be publicly named) in association with each other suggests
43 that these enormous carnivores may have hunted in packs. Interestingly,
44 the largest known land animals of all time, <LINK content="titanosaurs"/>
45 such as <NOMEN name="Argentinosaurus"/>, lived alongside these largest
46 land predators of all time. It is possible that packs of South American
47 carcharodontosaurines, each measuring up to 45 feet long, might have
48 preyed upon herds of 130+-foot-long titanosaurs.</P>
50 <P header="An Abelisaur Link?"> There are some cranial similarities
51 between carcharodontosaurines and <LINK content="abelisaurs"/>, another
52 group of Gondwanan (Southern Hemisphere) carnivores. This may be due to
53 convergence, but some have proposed that carcharodontosaurines are not
54 <LINK content="carnosaurs"/>, but <LINK content="neoceratosaurs"/> more
55 closely related to abelisaurs. But other characteristics, such as the
56 three-fingered hand (neoceratosaurs have four fingers), cast doubt on this
61 <TAXON name="Alvarezsauria" nickname="Freakish Digging(?) Runners">
62 <WORD key="1" content="bird"/>
64 <CLADE name="Alvarezsauria" silhouette="alvarezsauria">
66 <NOMEN name="Alvarezsaurus"/>'s taxon
68 <CLADE name="Alvarezsauridae">
69 <AUTHOR type="non" name="Sereno" year="1999"/>
70 <CGENUS name="Alvarezsaurus"/>
72 <CGENUS name="Patagonykus"/>
73 <CLADE name="Mononykinae" in="Mononykus, Parvicursor, Shuvuuia">
74 <CSYNONYM name="Parvicursorinae"/>
76 <TIME section="late" value="Maastrichtian"/>
77 <PLACE name="Montana"/>
79 <CGENUS name="Mononykus"/>
80 <CGENUS name="Ornithomimus minutus"/>
81 <CGENUS name="Parvicursor"/>
82 <CGENUS name="Shuvuuia"/>
89 <P header="Where Do They Belong?"> This recently discovered group has
90 proven difficult to place. The original member, <NOMEN
91 name="Alvarezsaurus"/>, was originally given its own family in <LINK
92 content="Ceratosauria"/>. When <NOMEN name="Mononykus"/> was first
93 discovered, it proved a bafflement. It had <LINK content="bird"/>-like
94 features (the skull, a keeled breastbone), unbirdlike features (the tail),
95 features like <LINK content="arctometatarsalian coelurosaurs"/> (pinched
96 middle metatarsal), and some features completely unique (the single,
97 hooked claw on its stubby arms). (NOTE: Some of these fossils have been
98 reassigned to the very closely related <NOMEN name="Shuvuuia"/>.)</P>
100 <P> The discovery of <NOMEN name="Patagonykus"/>, a creature seemingly
101 transitional between the more primitive <NOMEN name="Alvarezsaurus"/> and
102 the more derived mononykines, showed that all three probably belonged
103 to the same group. They are now generally though to be primitive birds,
104 although some think they may be related to <LINK content="ornithomimosaurs"/>.
105 (One piece of alvarezsaur ankle found by O. C. Marsh in the late 1800's was
106 actually assigned to the genus <NOMEN name="Ornithomimus"/>.) </P>
108 <P header="Their Niche"> Alvarezsaurs were small, terrestrial animals with
109 long legs. Their niche is far from certain. Since their stubby forearms
110 were built so powerfully, it has been suggested that they used them for
111 digging. (In fact, some think that their sterna were keeled as a digging
112 adaptation, similar to moles, and that they evolved keeled sterna
113 separately from birds, which evolved it for flying.) The overall body plan
114 of alvarezsaurs is not that of a burrower, but it has been suggested that
115 they might have fed on colonial insects, ripping into nests with their
116 single-clawed hands. </P>
120 <TAXON name="Anapsida" nickname='"No Holes" - Turtles & Kin' simple="1">
121 <WORD key="1" essay="1" content="turtles"/>
122 <WORD essay="1" content="archelon, sea turtle, turtle"/>
124 <CLADE name="Anapsida" in="Chelonia" out="Diapsida" silhouette="anapsida">
128 <CSYNONYM name="Parareptilia"/>
129 <CLADE name="Millerettidae" q="1" extinct="1"/>
130 <CLADE name="Procolophonomorpha">
131 <CLADE name="Nyctiphruretia" extinct="1">
132 <CGENUS name="Nycteroleter"/>
133 <CLADE name="Nyctiphruretidae"/>
135 <CLADE name="Procolophoniformes">
136 <CLADE name="Procolophonidae" extinct="1"/>
138 <CLADE name="Lanthanosuchoidea" extinct="1" q="1">
139 <CGENUS name="Acleisterorhinus"/>
140 <CLADE name="Lanthanosuchidae"/>
143 <CLADE name="Sclerosauridae" extinct="1"/>
145 <CLADE name="Rhipaeosauridae" extinct="1"/>
147 <CLADE name="Pareiasauridae" extinct="1"/>
149 <CLADE name="Proganochelyidae" extinct="1"/>
150 <CLADE name="Proterochersidae" extinct="1"/>
151 <CLADE name="Casichelonia">
152 <CLADE name="Chelycarapookidae" extinct="1" q="1"/>
153 <CLADE name="Kallokibotiidae" extinct="1" q="1"/>
154 <CLADE name="Simemylidae" extinct="1" q="1"/>
155 <CLADE name="Chelonia" crown="1" content="turtles">
156 <CSYNONYM name="Testudinata"/>
157 <CSYNONYM name="Testudines"/>
158 <CLADE name="Pleurodira">
162 <CLADE name="Chelyidae"/>
163 <CLADE name="Eusarkiidae" extinct="1" q="1"/>
164 <CLADE name="Platychelidae" extinct="1" q="1"/>
166 <CLADE name="Araripemydidae" extinct="1"/>
168 <CLADE name="Pelomedusidae"/>
169 <CLADE name="Podocnmemoidea">
170 <CLADE name="Bothremydidae"/>
171 <CLADE name="Podocnemidae"/>
176 <CLADE name="Cryptodira">
180 <CLADE name="Baenidae" extinct="1"/>
181 <CLADE name="Glyptopsidae" extinct="1">
182 <CSYNONYM name="Pleurosternidae" q="1"/>
184 <CLADE name="Meiolaniidae" extinct="1"/>
185 <CLADE name="Neeurankylidae" extinct="1"/>
186 <CLADE name="Eucryptodira">
190 <CLADE name="Plesiochelyidae" extinct="1"/>
192 <CGENUS name="Xinjiangchelys" extinct="1" q="1"/>
194 <CLADE name="Sinemydidae" extinct="1"/>
196 <CLADE name="Chelydridae" content="snapping turtles"/>
198 <CLADE name="Chelonioidea" content="sea turtles">
200 <CLADE name="Cheloniidae"/>
201 <CLADE name="Toxochelyidae" extinct="1"/>
204 <CLADE name="Dermochelyidae"/>
205 <CLADE name="Protostegidae" extinct="1"/>
206 <CLADE name="Thalassemyidae" extinct="1"/>
209 <CLADE name="Chelomacryptodira">
210 <CLADE name="Testudinoidea">
211 <CLADE name="Emydidae" content="box & water turtles"/>
212 <CLADE name="Testudinidae" content="terrapins"/>
214 <CLADE name="Trionychoidea">
215 <CLADE name="Carettochelyidae"/>
216 <CLADE name="Dermatemydidae"/>
217 <CLADE name="Kinosternidae" content="mud & musk turtles"/>
218 <CLADE name="Trionychidae" content="softshell turtles"/>
239 <P> Anapsida is a clade of of <LINK content="reptiles"/> with no fenestrae
240 (openings) in the back of their skulls. It includes large herbivores like
241 pareiasaurs as well as modern-day turtles. During the <LINK
242 content="Mesozoic Era"/>, "The Age of Reptiles", turtles grew to great
243 sizes. Some, like <NOMEN nolink="1" name="Archelon"/>, were the size of a
246 <P>In traditional usage, Anapsida included all <LINK content="amniotes"/>
247 without antorbital fenestrae. It has now been restricted to those sharing
248 more recent ancestry with chelonians (turtles) than with other extant
249 amniote groups. Membership is mostly the same, but excludes basalmost
250 <LINK content="sauropsids"/> (e.g. <LINK content="mesosaurids"/>) and
251 basal romeriids (e.g. <LINK content="captorhinids"/>).
254 <P> Within Reptilia, anapsids are probably the most distant relatives of
255 <LINK content="dinosaurs"/>. </P>
259 <TAXON name="Animalia" nickname="Animals" simple="1">
260 <WORD key="1" content="fauna, invertebrate, invertebrates"/>
261 <WORD essay="1" content="mollusk, ammonoid, ammonoids, rudist clams"/>
263 <CLADE name="Animalia" silhouette="animalia">
264 <AUTHOR name="Linnaeus"/>
268 <CSYNONYM name="Metazoa"/>
269 <CLADE name="Porifera" content="sponges"/>
271 <CLADE name="Phagocytellozoa"/>
273 <CLADE name="Mesozoa" q="1"/>
275 <CLADE name="Monoblastozoa" q="1"/>
276 <CLADE name="Eumetazoa">
277 <CLADE name="Cnidaria" content="hydrae, corals, jellyfish"/>
279 <CLADE name="Ctenophora" content="comb jellies"/>
280 <CLADE name="Bilateralia" content="bilaterally symmetrical animals">
281 <CLADE name="Acoelomata">
282 <CLADE name="Xenoturbellida"/>
284 <CLADE name="Gnathostomulida"/>
285 <CLADE name="Platyhelminthes" content="flatworms"/>
288 <CLADE name="Coelomata" content="animals with a true body cavity">
289 <CLADE name="Protostomia">
290 <CLADE name="Bryozoa" content='"moss creatures"' q="1">
291 <CSYNONYM name="Ectoprocta"/>
293 <CLADE name="Cycliophora" q="1"/>
294 <CLADE name="Entoprocta" q="1"/>
295 <CLADE name="Pseudocoelomata" q="1">
296 <CSYNONYM name="Aschelminthes"/>
298 <CLADE name="Chaetognatha"/>
299 <CLADE name="Protoconodonta" extinct="1"/>
303 <CLADE name="Nematoda">
304 <CSYNONYM name="Nemata"/>
306 <CLADE name="Nematomorpha"/>
309 <CLADE name="Gastrotricha"/>
311 <CLADE name="Acanthocephala"/>
312 <CLADE name="Rotifera" content="rotifers"/>
318 <CLADE name="Arthropodomorpha">
319 <CLADE name="Arthropoda" content="insects, myriapods, arachnids, crustaceans, trilobites, tardigrades?, onychophorans?, etc."/>
320 <CLADE name="Sprigginida" extinct="1"/>
325 <CLADE name="Amiskwiida" extinct="1"/>
326 <CLADE name="Nemertea">
327 <CSYNONYM name="Nemertinea"/>
331 <CLADE name="Lobatocerebrida"/>
333 <CLADE name="Myzostomida" q="1"/>
335 <CLADE name="Banffida" extinct="1"/>
336 <CLADE name="Echiura">
337 <CSYNONYM name="Echiuroidea"/>
341 <CLADE name="Annelida" content="earthworms, leeches, bristleworms, etc."/>
343 <CLADE name="Vestimentifera"/>
344 <CLADE name="Pogonophora" content="pogonophores"/>
353 <CLADE name="Phoronida"/>
355 <CLADE name="Tommotiida" extinct="1"/>
356 <CLADE name="Brachiopoda"/>
360 <CLADE name="Palaeoscolecida" extinct="1"/>
362 <CLADE name="Kinorhyncha"/>
364 <CLADE name="Loricifera"/>
365 <CLADE name="Priapulida">
366 <CSYNONYM name="Priapuloidea"/>
373 <CLADE name="Tullimonsterida" content='"The Tully Monster"' extinct="1" q="1"/>
376 <CLADE name="Hyolitha" extinct="1"/>
377 <CLADE name="Sipuncula">
378 <CSYNONYM name="Sipunculoidea"/>
383 <CLADE name="Chancelloriida" extinct="1"/>
384 <CLADE name="Sachitida" extinct="1"/>
387 <CLADE name="Mollusca" content="chitons, snails, bivalves, cephalopods, etc."/>
389 <CLADE name="Siphogonuchitida" extinct="1"/>
390 <CLADE name="Halkieriida" extinct="1"/>
400 <CLADE name="Deuterostomia">
403 <CLADE name="Cambroclaves" extinct="1"/>
405 <CLADE name="Echinodermata" content="crinoids, starfish, sea cucumbers, sea urchins, brittle stars"/>
406 <CLADE name="Heterostelea" extinct="1"/>
410 <CLADE name="Dinomischida" extinct="1"/>
412 <CLADE name="Eldoniida" extinct="1"/>
414 <CLADE name="Rotadisciida" extinct="1"/>
415 <CLADE name="Paropsonemida" extinct="1"/>
421 <CLADE name="Brachiolitha"/>
423 <CLADE name="Hemichordata" content="acorn worms"/>
424 <CLADE name="Chordata" content="animals with a notochord">
425 <CLADE name="Calcichordata" extinct="1" q="1"/>
426 <CLADE name="Urochordata" content="sea squirts">
427 <CSYNONYM name="Tunicata"/>
430 <CLADE name="Cephalochordata" content="lancelets, Pikaia, etc.">
431 <CSYNONYM name="Acraniata"/>
433 <CLADE name="Craniata" content="chordates with heads">
434 <CLADE name="Myxini" content="hagfish"/>
435 <CLINK name="Vertebrata"/>
452 <P> Among Earth's enormously vast array of animals, <LINK
453 content="dinosaurs"/> belong to the <LINK content="vertebrate"/> clade,
454 which is characterized by the possession of a backbone. </P>
458 <TAXON name="Ankylosauria" nickname="Dinosaurian Tanks">
459 <WORD key="1" content="nodosaurs, armored, scutes, spikes, armoured"/>
461 <CLADE name="Ankylosauria" in="Ankylosaurus" out="Stegosaurus" silhouette="ankylosauria">
462 <MEANING><NOMEN name="Ankylosaurus"/>' taxon</MEANING>
463 <AUTHOR type="sensu" name="Carpenter" year="1997"/>
465 <TIME value="Aptian"/>
466 <PLACE name="Australia"/>
467 <REMAINS content="teeth, ribs"/>
469 <CGENUS name="Cryptosaurus" incertae="1"/>
470 <CGENUS name="Heishansaurus" incertae="1"/>
471 <CGENUS name="Peishansaurus" incertae="1"/>
472 <CGENUS name="Priconodon" incertae="1"/>
473 <CGENUS name="Priodontognathus" incertae="1"/>
474 <CGENUS name="Rhadinosaurus" incertae="1" q="1"/>
475 <CGENUS name="Stegosaurides" incertae="1" q="1"/>
476 <CGENUS name="Tianzhenosaurus" incertae="1"/>
477 <CGENUS incertae="1" name="Tyreophorus" q="1"/>
479 <PLACE name="Texas"/>
482 <TIME value="Albian"/>
486 <TIME value="Maastrichtian"/>
487 <PLACE name="India"/>
488 <REMAINS museum="IM" id="K20/350" content="skull roof portion"/>
490 <CGENUS name="Minmi"/>
491 <CLADE name="Ankylosauroidea" in="Ankylosaurus, Nodosaurus">
492 <CLADE name="Nodosauridae" in="Nodosaurus" out="Ankylosaurus" silhouette="nodosauridae">
493 <UNNAMED comment="giant">
494 <TIME value="EK" section="early"/>
498 <TIME value="Albian"/>
499 <TIME value="Cenomanian" section="early"/>
500 <PLACE name="Africa"/>
503 <TIME value="Campanian"/>
504 <PLACE name="Montana"/>
507 <PLACE name="Antarctica"/>
509 <CGENUS name="Animantarx" incertae="1"/>
510 <CGENUS name="Dracopelta" incertae="1"/>
511 <CGENUS name="Niobrarasaurus" incertae="1"/>
512 <CGENUS name="Nodosaurus" incertae="1"/>
513 <CGENUS name="Palaeoscincus" incertae="1"/>
514 <CGENUS name="Sarcolestes" incertae="1"/>
515 <CGENUS name="Struthiosaurus" incertae="1"/>
516 <CGENUS name="Hylaeosaurus"/>
518 <CGENUS name="Pawpawsaurus"/>
520 <CGENUS name="Sauropelta"/>
521 <CLADE name="Panoplosaurinae">
522 <CSYNONYM name="Edmontoniinae"/>
523 <CGENUS name="Edmontonia"/>
524 <CGENUS name="Panoplosaurus"/>
529 <CLINK name="Ankylosauridae"/>
534 <P header="Solid Protection"> Ankylosaurs include the most heavily armored
535 dinosaurs of all, the "tanks" of the <LINK content="Mesozoic"/>. The
536 entire back was covered with bony plates, studs, and spikes. So was the
537 head, right down to the eyelids! (Bony eyelids have been found in <NOMEN
538 name="Pawpawsaurus"/> and <NOMEN name="Euoplocephalus"/>, which are so
539 distantly related within Ankylosauroidea as to suggest that all
540 ankylosauroids had bony eyelids, at least primitively.) </P>
542 <P> Some nodosaurids bore very large spikes along their sides, the largest
543 often sprouting from the shoulders. These may have been used as defense,
544 weapons in rivalry, or both. </P>
546 <P header="Geographic Distribution"> These animals are known from all
547 continents except South America and Africa. They were most prevalent in
548 Laurasia (the northern supercontinent). </P>
552 <TAXON name="Ankylosauridae" nickname="Club-Tails" silhouette="ankylosaurinae-shamosaurinae">
553 <WORD key="1" content="armored, armoured, tail, club, weapon, spike"/>
555 <CLADE name="Ankylosauridae" in="Ankylosaurus" out="Nodosaurus" silhouette="ankylosauria">
557 <TIME section="early" value="Maastrichtian"/>
558 <PLACE name="Argentina"/>
561 <TIME value="Campanian"/>
562 <PLACE name="France"/>
564 <CGENUS name="Gargoyleosaurus" incertae="1"/>
565 <CGENUS name="Tianchisaurus"/>
566 <CLADE name="Polacanthinae" in="Polacanthus" out="Ankylosaurus, Shamosaurus">
567 <CGENUS name="Acanthopholis" q="1"/>
568 <CGENUS name="Anoplosaurus" q="1"/>
569 <CGENUS name="Texasetes"/>
570 <CGENUS name="Mymoorapelta"/>
571 <CGENUS name="Silvisaurus" q="1"/>
572 <CLADE name="Polacanthini">
573 <CGENUS name="Gastonia"/>
574 <CGENUS name="Hoplitosaurus" q="1"/>
575 <CGENUS name="Polacanthus"/>
578 <CLADE silhouette="ankylosaurinae-shamosaurinae">
579 <CGENUS name="Bibleyhallorum" incertae="1"/>
580 <CLADE name="Shamosaurinae" in="Shamosaurus" out="Ankylosaurus, Polacanthus">
582 <TIME value="Cenomanian"/>
583 <PLACE name="U.S.A."/>
585 <CGENUS name="Gobisaurus" q="1"/>
586 <CGENUS name="Shamosaurus"/>
588 <CLADE name="Ankylosaurinae" in="Ankylosaurus" out="Polacanthus, Shamosaurus">
589 <CGENUS name="Sauroplites" incertae="1"/>
590 <CGENUS name="Tsagantegia"/>
592 <CLADE name="Ankylosaurini">
593 <CGENUS name="Ankylosaurus"/>
594 <CGENUS name="Euoplocephalus"/>
596 <CLADE name="Stegopeltini" q="1">
597 <UNNAMED comment="San Diego"></UNNAMED>
598 <CGENUS name="Glyptodontopelta"/>
599 <CGENUS name="Stegopelta"/>
601 <CLADE name="Syrmosaurini">
602 <CGENUS name="Amtosaurus"/>
603 <CGENUS name="Maleevus"/>
604 <CGENUS name="Pinacosaurus"/>
605 <CGENUS name="Shanxia"/>
606 <CGENUS name="Talarurus"/>
608 <CGENUS name="Nodocephalosaurus" q="1"/>
609 <CGENUS name="Saichania"/>
610 <CGENUS name="Tarchia"/>
618 <CLADOGRAM alternate="1">
619 <CLADE name="Ankylosauridae">
620 <CGENUS name="Gargoyleosaurus"/>
622 <CGENUS name="Minmi"/>
623 <CGENUS name="Shamosaurus"/>
625 <CGENUS name="Gastonia"/>
626 <CGENUS name="Pinacosaurus"/>
627 <CLADE name="Ankylosaurinae"/>
633 <P header="A Crippling Weapon"> A large club at the end of the tail
634 distinguishes ankylosaurines and shamosaurines from the more primitive
635 <LINK content="ankylosaurs"/> They probably used this club to give
636 crippling blows to potential predators. A similar structure existed in the
637 <LINK content="sauropod"/> <NOMEN name="Shunosaurus"/>, as well as the
638 glyptodonts, an extinct group of giant South American <LINK
639 content="mammals"/> related to armadillos. Ankylosaurines also had
640 shorter, more triangular skulls than other ankylosaurs and no spikes along
643 <P header="The Varieties"> Polacanthines were once classified as
644 nodosaurids, but are now recognized as a distinct clade closer to the
645 Ankylosaurinae. It was recently thought that they had small tail clubs,
646 but this has been refuted. </P>
648 <P> Shamosaurines had narrow snouts, especially compared to the very wide
649 snouts of ankylosaurines. This may reflect different niches.</P>
651 <P> Many ankylosaurines had complex, looping nasal passages, possibly to
652 enhance their sense of smell. </P>
656 <TAXON name="Archosauromorpha" nickname='"Ruling Reptiles"' simple="1">
657 <INCLUDED content="Euparkeria, Hsisosuchus, Lewisuchus, Postosuchus, Proterosuchus, Saltopus"/>
659 <CLADE name="Archosauromorpha" in="Archosauria" out="Lepidosauria" silhouette="archosauromorpha">
660 <MEANING>archosaur forms</MEANING>
661 <CGENUS name="Doswellia" incertae="1"/>
662 <CGENUS name="Elastichosuchus" incertae="1"/>
663 <CGENUS name="Trilophosaurus"/>
664 <CLADE name="Rhynchosauridae"/>
665 <CLADE name="Prolacertiformes">
669 <CSYNONYM name="Protorosauria"/>
670 <CGENUS name="Protorosaurus"/>
672 <CGENUS name="Kadimakara" q="1"/>
673 <CGENUS name="Malutinisuchus" q="1"/>
674 <CGENUS name="Prolacertoides" q="1"/>
675 <CGENUS name="Trachelosaurus" q="1"/>
677 <CGENUS name="Prolacerta"/>
680 <CGENUS name="Jesairosaurus"/>
681 <CGENUS name="Malerisaurus"/>
684 <CGENUS name="Macrocnemus"/>
686 <CLADE name="Megalancosauridae">
687 <CSYNONYM name="Drepanosauridae"/>
690 <CGENUS name="Boreopricea"/>
692 <CGENUS name="Cosesaurus"/>
693 <CLADE name="Tanystropheidae"/>
702 <CLADE name="Archosauriformes" in="Archosauria, Proterosuchus">
703 <MEANING>archosaur forms</MEANING>
704 <AUTHOR name="Gauthier" year="1984"/>
705 <CLADE name="Proterosuchidae"/>
707 <CLADE name="Erythrosuchidae"/>
709 <CGENUS name="Euparkeria" exinct="1"/>
710 <CLADE name="Archosauria" in="Neornithes, Crocodylia">
711 <AUTHOR name="Cope" year="1869"/>
712 <AUTHOR type="sensu" name="Gauthier" year="1984"/>
713 <CSYNONYM name="Avesuchia">
714 <AUTHOR name="Benton" year="1999"/>
719 <CGENUS name="Lukousaurus" incertae="1"/>
720 <CGENUS name="Saltoposuchus" incertae="1" q="1"/>
721 <CLADE name="Pseudosuchia" in="Crocodylia" out="Neornithes">
722 <AUTHOR name="Zittel" year="1890"/>
723 <AUTHOR type="sensu" name="Gauthier" year="1986"/>
724 <CSYNONYM name="Crocodylotarsi"/>
728 <CLADE name="Proterochampsidae" q="1"/>
730 <CLADE name="Erpetosuchidae" q="1"/>
731 <CLADE name="Ctenosauriscidae" q="1"/>
732 <CLADE name="Crurotarsi" in="Ornithosuchus, Crocodylia">
736 <AUTHOR name="Sereno" year="1991"/>
737 <CLADE name="Ornithosuchidae"/>
739 <CLADE name="Parasuchia" content="phytosaurids">
740 <AUTHOR name="Huxley" year="1859"/>
744 <CSYNONYM name="Phytosauria"/>
747 <CLADE name="Prestosuchidae"/>
749 <CGENUS name="Lewisuchus" q="1"/>
750 <CGENUS name="Turfanosuchus" q="1"/>
751 <CLADE name="Suchia" in="Crocodylia, Stagonolepis">
755 <CSYNONYM name="Pseudosuchia" sensu="Benton" year="1988"/>
756 <CLADE name="Aetosauria" content="stagonolepidids">
757 <CSYNONYM name="Aëtosauria"/>
759 <CLADE name="Rauisuchia" in="Crocodylia, Rauisuchus">
761 <NOMEN nolink="1" name="Rauisuchus"/>' taxon
763 <CLADE name="Rauisuchidae"/>
765 <CGENUS name="Gracilisuchus" q="1"/>
766 <CLADE name="Postosuchidae"/>
767 <CLADE name="Paracrocodylomorpha" in="Crocodylia, Poposaurus">
769 beside Crocodylomorpha
771 <CLADE name="Poposauridae"/>
772 <CLINK name="Crocodylomorpha"/>
783 <CLADE name="Ornithosuchia" in="Neornithes" out="Crocodylia" silhouette="ornithosuchia">
784 <AUTHOR name="Gauthier" year="1986"/>
785 <CSYNONYM name="Avemetatarsalia">
786 <AUTHOR name="Benton" year="1999"/>
788 <CGENUS name="Saltopus" incertae="1" q="1"/>
789 <MEANING>bird crocodiles</MEANING>
790 <CLINK name="Ornithodira"/>
798 <CLADOGRAM alternate="1">
799 <CLADE name="Archosauromorpha">
800 <CLADE name="Rhynchosauridae"/>
801 <CLADE name="Ornithodira">
802 <CLADE name="Prolacertiformes">
803 <CSYNONYM name="Pterosauromorpha"/>
804 <CGENUS name="Boreopricea"/>
805 <CGENUS name="Jesairosaurus"/>
806 <CGENUS name="Prolacerta"/>
807 <CGENUS name="Protorosaurus"/>
808 <CLADE name="Megalancosauridae"/>
810 <CGENUS name="Macrocnemus"/>
812 <CLADE name="Tanystropheidae"/>
814 <CGENUS name="Langobardisaurus"/>
816 <CGENUS name="Cosesaurus"/>
818 <CGENUS name="Sharovipteryx"/>
819 <CLINK name="Pterosauria"/>
826 <CLADE name="Dinosauromorpha">
827 <CLADE name="Archosauriformes">
828 <CLADE name="Proterosuchidae">
830 <CLADE name="Erythrosuchidae"/>
832 <CLADE name="Proterochampsidae"/>
834 <CGENUS name="Euparkeria"/>
836 <CLADE name="Parasuchia"/>
837 <CLADE name="Archosauria">
838 <CLADE name="Pseudosuchia"/>
839 <CLADE name="Ornithosuchia">
840 <CLADE name="Ornithosuchidae"/>
842 <CGENUS name="Scleromochlus"/>
844 <CGENUS name="Lagerpeton"/>
846 <CGENUS name="Marasuchus"/>
847 <CLINK name="Dinosauria"/>
864 <P> Archosauromorpha includes all <LINK content="sauropsids"/> with
865 four-chambered hearts, an evolutionary innovation that permitted them
866 higher activity levels and terrestrial dominance throughout the <LINK
867 content="Mesozoic Era"/>. </P>
869 <P header="Classification"> The forms shown here were once all included in
870 Archosauria in the "grab-bag" taxon "Thecodontia" -- any archosaur that
871 wasn't a <LINK content="crocodylian"/>, a <LINK content="pterosaur"/>, or
872 a <LINK content="dinosaur"/>. This form of classification was abandoned
873 once knowledge about these animals increased. </P>
875 <P> The non-archosaur archosauromorphs, or "protoarchosaurs", show fairly
876 wide diversity, from small hunters with insanely long necks like <NOMEN
877 name="Tanystropheus" nolink="1"/> to large, beaked herbivores like the
878 rhynchosaurs to the megalancosaurids, bizarre climbers with prehensile
881 <P> The two major groups of Archosauria proper are rather poorly named.
882 Pseudosuchia means "false crocodiles", yet it includes true ones.
883 Ornithosuchia was named after the creature <NOMEN name="Ornithosuchus"
884 nolink="1"/>, and defined as all animals sharing more recent ancestry with
885 birds than with crocodiles. Unfortunately, subsequent analyses have shown
886 that <NOMEN name="Ornithosuchus" nolink="1"/> was not an ornithosuchian,
887 but a pseudosuchian! </P>
889 <P header="The Struggle for Supremacy"> Pseudosuchians became the dominant
890 terrestrial animals after the demise of the two previous <LINK
891 content="synapsid"/> "dynasties" -- the "<LINK content="pelycosaurs"/>"
892 and the non-<LINK content="mammalian"/> <LINK content="therapsids"/>. They
893 diversified into many niches: armored herbivores (aetosaurs), big
894 carnivores (rauisuchians), tiny sprinters (<NOMEN name="Lewisuchus"
895 nolink="1"/>), and water-dwellers (parasuchians and <LINK
896 content="crocodylomorphs"/>). There is evidence that many pseudosuchians
897 may have been agile, active creatures, unlike the only modern
898 pseudosuchians (<LINK content="crocodylians"/>) which have reverted to a
899 sluggish lifestyle. </P>
901 <P> But by the end of the <LINK content="Triassic"/> they had been
902 outcompeted by their fellow archosaurs, the ornithosuchian <LINK
903 content="ornithodirans"/>. Dinosaurs and pterosaurs would continue to
904 dominate terrestrial and aerial niches until the end of the <LINK
905 content="Mesozoic"/>, far longer than any previous or subsequent
906 terrestrial "dynasty" (and they <U>still</U> dominate aerial niches!). Of
907 all the pseudosuchians, only the aquatic crocodylomorphs survived beyond
908 the <LINK content="Triassic"/>. </P>
912 <TAXON name="Avialae" nickname="Birds & Near-Birds" silhouette="aves">
913 <WORD key="1" content="origin, feather, link"/>
914 <WORD key="1" essay="1" content="bird, birds, archaeopterygian"/>
916 <CLADE name="Avialae" in="Neornithes" out="Deinonychus" silhouette="paraves">
917 <AUTHOR name="Gauthier" year="1986"/>
918 <AUTHOR type="sensu" name="Padian" year="1997"/>
919 <UNNAMED indet="1" cf="Archaeopteryx">
920 <TIME value="Cenomanian"/>
921 <PLACE name="Romania"/>
922 <REMAINS content="partial humerus"/>
925 <TIME value="Barremian" q="1"/>
926 <PLACE name="S. Korea"/>
927 <REMAINS content="forelimb with feather impressions"/>
929 <CGENUS name="Bambiraptor" q="1" incertae="1"/>
930 <CGENUS name="Holbotia" incertae="1"/>
931 <CGENUS name="Wyleyia" incertae="1" q="1"/>
932 <CGENUS incertae="1" name="Archaeoraptor" silhouette="aves"/>
933 <CGENUS q="1" name="Rahonavis"/>
934 <CGENUS q="1" name="Unenlagia" silhouette="paraves-flightless"/>
935 <CLADE name="Aves" in="Archaeopteryx, Neornithes" silhouette="aves">
936 <AUTHOR name="Linnaeus"/>
937 <AUTHOR type="sensu" name="Chiappe"/>
938 <CSYNONYM name="Avialae" sensu="Gauthier" year="1986"/>
942 <CLADE name="Archaeopterygiformes">
943 <CSYNONYM name="Archaeornithes"/>
944 <CGENUS name="Archaeopteryx"/>
946 <CLADE in="Neornithes" out="Archaeopteryx">
947 <CSYNONYM name="Ornithurae" sensu="Gauthier" year="1986"/>
948 <CLADE name="Metornithes" in="Mononykus, Neornithes">
949 <CLINK q="1" name="Alvarezsauria"/>
950 <CLADE name="Pygostylia" in="Confuciusornis, Neornithes" silhouette="pygostylia">
952 pygostyles <LOW>("Parson's noses")</LOW>
954 <CGENUS incertae="1" name="Jibeinia"/>
955 <CGENUS incertae="1" name="Liaoxiornis"/>
956 <CLADE name="Confuciusornithidae">
957 <CGENUS name="Changchengornis"/>
958 <CGENUS name="Confuciusornis"/>
961 <CGENUS q="1" name="Noguerornis"/>
962 <CLADE name="Ornithothoraces" in="Iberomesornis, Neornithes">
963 <MEANING><LOW>modern</LOW> bird chests</MEANING>
964 <CGENUS incertae="1" name="Otogornis"/>
965 <CGENUS incertae="1" name="Platanavis"/>
966 <CLINK name="Enantiornithes"/>
967 <CLADE name="Euornithes" in="Neornithes" out="Sinornis">
968 <MEANING>true birds</MEANING>
969 <AUTHOR name="Sereno" year="1998"/>
970 <CSYNONYM name="Ornithurae" sensu="Feduccia"/>
971 <CGENUS q="1" name="Liaoningornis"/>
972 <CLADE name="Gansuiformes" incertae="1">
973 <CGENUS name="Gansus"/>
975 <CLINK name="Ornithurae"/>
985 <CLADOGRAM alternate="1">
986 <CLADE name="Avialae">
988 <CLADE name="Metornithes"/>
989 <CLADE name="Archaeornithes">
993 <CSYNONYM name="Archaeopterygiformes"/>
994 <CGENUS name="Unenlagia"/>
995 <CLADE name="Archaeopterygidae">
996 <CGENUS name="Archaeopteryx"/>
997 <CGENUS name="Rahonavis"/>
1003 <CLADOGRAM alternate="1">
1004 <CLADE name="Avialae">
1005 <CLADE name="Metornithes">
1006 <CLADE name="Alvarezsauria"/>
1008 <CGENUS name="Archaeopteryx"/>
1009 <CLADE name="Pygostylia"/>
1014 <CLADOGRAM alternate="1">
1015 <CLADE name="Avialae">
1016 <CGENUS name="Adasaurus"/>
1019 <CGENUS name="Rahonavis"/>
1020 <CGENUS name="Unenlagia"/>
1021 <CGENUS name="Bambiraptor"/>
1024 <CGENUS name="Archaeopteryx"/>
1025 <CLADE name="Metornithes"/>
1030 <CLADOGRAM alternate="1">
1031 <CLADE name="Avialae">
1032 <CLINK name="Troodontidae"/>
1033 <CLADE name="Aves"/>
1036 <CLADOGRAM alternate="1">
1038 <CSYNONYM name="Pygostylia"/>
1039 <CLADE name="Archaeornithes">
1040 <CGENUS name="Archaeopteryx"/>
1041 <CLADE name="Confuciusornithidae"/>
1044 <CSYNONYM name="Ornithothoraces" sensu="Chatterjee"/>
1045 <CGENUS name="Protoavis"/>
1046 <CLADE name="Ornithothoraces">
1047 <CSYNONYM name="Pygostylia" sensu="Chatterjee"/>
1052 <CLADOGRAM alternate="1">
1054 <CSYNONYM name="Ornithothoraces"/>
1055 <CSYNONYM name="Pygostylia"/>
1056 <CLADE name="Ornithurae"/>
1057 <CLADE name="Saururae" in="Archaeopteryx" out="Neornithes">
1061 <CSYNONYM name="Sauriurae"/>
1062 <CGENUS name="Archaeopteryx"/>
1063 <CGENUS name="Caudipteryx"/>
1064 <CGENUS name="Protarchaeopteryx"/>
1065 <CGENUS name="Yandangornis"/>
1066 <CLADE name="Enantiornithes"/>
1071 <P header="Origins">Birds evolved from small, possibly "sickle-clawed"
1072 <LINK content="coelurosaurs"/> probably sometime during the <LINK
1073 content="Jurassic"/> (some have suggested the <LINK content="Triassic"/>),
1074 as did their close relatives the <LINK content="deinonychosaurs"/>. The
1075 earliest known definite bird is the European <NOMEN
1076 name="Archaeopteryx"/>, a small flying predator from the Late Jurassic.
1077 The North American <NOMEN name="Protoavis"/> has been interpreted as a
1078 Late Triassic bird that is more "advanced" than <NOMEN
1079 name="Archaeopteryx"/>, but few <LINK content="dinosaur"/>/bird
1080 researchers agree with this at present.</P>
1082 <P header="Advanced Forms">Pygostylian birds are characterized by a
1083 pygostyle, a fusion of the vertebrae at the end of the tail. This trait
1084 seems to have evolved convergently in at least one <LINK
1085 content="oviraptorosaur"/> (<NOMEN name="Nomingia"/>) and at least one
1086 <LINK content="megalancosaurid"/> (<NOMEN name="Drepanosaurus"
1089 <P>Ornithothoracean birds, a large subset of pygostylians that includes
1090 <LINK content="modern birds"/>, have a "modern-style" thorax and an alula,
1091 or "bastard wing" -- a group of feathers associated with the first finger
1092 that aids maneuverability in flight.</P>
1094 <P header="From the Trees or From the Ground?">Unlike the other two groups of
1095 flying <LINK content="vertebrates"/>, <LINK content="pterosaurs"/> and
1096 <LINK content="bats"/>, the hindlimbs of birds are not in any way coupled with
1097 the wings, and remain free for running. Due to this and other pieces of
1098 evidence, some dinosaur researchers argue that birds did not evolve from a
1099 tree-dwelling ancestor, as the other groups are thought to have. Recent
1100 studies suggest that <NOMEN name="Archaeopteryx"/> could run fast enough to
1101 take off from the ground, bolstering this hypothesis, commonly known as the
1102 "Ground Up" hypothesis. </P>
1104 <P>But many disagree with this idea, arguing that flight in birds evolved as
1105 it seems to have in bats and pterosaurs -- from the "Trees Down".
1106 They hold that bird ancestors were scansorial coelurosaurs which leaped from
1107 tree to tree, then evolved into gliders, and from there to fliers. The
1108 facts that <NOMEN name="Archaeopteryx"/> has claws sharply recurved for
1109 climbing and that its first toe is reversed for perching support this
1112 <P>As of now, the fossil evidence does not clearly favor either the
1113 "Trees Down" or "Ground Up" hypotheses of the evolution
1114 of flight in birds. </P>
1116 <P header="An Opposing View">The hypothesis that birds descended from
1117 dinosaurs has been around for a long time. Thomas Huxley (a.k.a. "Darwin's
1118 bulldog") proposed such a relationship based on similarities between
1119 <NOMEN name="Archaeopteryx"/> and dinosaurs. This view was dismissed by
1120 Gerhard Heilmann, who noted that dinosaurs lack clavicles, which are not
1121 only present in birds but fused to form the furcula, or "wishbone".
1122 Heilmann's suggestion that birds and dinosaurs descended separately from
1123 "thecodont" (basal <LINK content="archosaurian"/>) stock held fast for
1124 most of the 1900's.</P>
1126 <P>Heilmann's view was finally dispelled by the discovery that some <LINK
1127 content="theropod"/> dinosaur fossils (such as those of <NOMEN
1128 name="Segisaurus"/>) <U>do</U> in fact have clavicles. In <LINK
1129 content="tetanuran"/> forms (such as <NOMEN name="Velociraptor"/>, <LINK
1130 content="oviraptorids"/>, <LINK content="allosaurids"/>), they are even
1131 fused to form furculae. These elements had often been mistaken for rib
1132 fragments. Additionally, clavicles are reduced or missing in some modern
1133 birds, and were likely so for many other theropods.</P>
1135 <P>A more recent objection to the dinosaur-bird link is the claim that
1136 embryological evidence shows the digits in the hands of modern birds to be
1137 II-III-IV, not I-II-III as in coelurosaurs and other <LINK
1138 content="tetanurans"/>. In fact, the story may be quite a bit more
1139 complicated. It is not certain that the element that has been interpreted
1140 as a vestigial digit I is in fact digit I. Furthermore, other studies show
1141 that frame shift can cause some birds to have digits aligned differently
1142 than in other birds, even with the same species.</P>
1144 <P>Opponents of the dinosaurian theory of bird origins have yet to
1145 propose an explicit alternate theory, generally stating that birds
1146 evolved from basal <LINK content="archosauromorphs"/> of some kind. They
1147 also have yet to explain why such an enormous degree of convergence
1148 would appear between birds and terrestrial <LINK content="theropods"/>
1149 when they represent separate niches.</P>
1153 <TAXON name="Carnosauria" nickname='"Meat Reptiles" - Mighty Hunters' silhouette="monolophosaurus">
1154 <WORD key="1" content="predator, hunter"/>
1155 <WORD essay="1" key="1" content="allosaurs"/>
1157 <CLADE name="Carnosauria" in="Allosaurus" out="Neornithes" silhouette="carnosauria">
1158 <AUTHOR name="von Huene" year="1914"/>
1159 <AUTHOR type="sensu" name="Gauthier" year="1986"/>
1160 <AUTHOR type="emended" name="Hutchinson, Padian" year="1997"/>
1162 flesh<LOW>-eating</LOW> lizards
1164 <UNNAMED indet="1" q="1">
1165 <TIME value="J" q="1"/>
1166 <PLACE name="France"/>
1167 <REMAINS content="braincase"/>
1169 <CGENUS name="Chilantaisaurus" incertae="1"/>
1170 <CGENUS incertae="1" name="Katsuyamasaurus" q="1"/>
1171 <CGENUS incertae="1" name="Mifunesaurus" q="1"/>
1172 <CGENUS incertae="1" name="Prodeinodon" q="1"/>
1173 <CGENUS incertae="1" name="Valdoraptor"/>
1174 <CSYNONYM name="Allosauria"/>
1175 <CSYNONYM name="Allosauroidea" sensu="Sereno" year="1998"/>
1176 <CGENUS name="Cryolophosaurus" silhouette="cryolophosaurus"/>
1177 <CGENUS name="Monolophosaurus" silhouette="monolophosaurus"/>
1178 <CLADE name="Allosauroidea" in="Allosaurus, Sinraptor">
1179 <CGENUS incertae="1" name="Lourinhanosaurus"/>
1180 <CLADE name="Sinraptoridae" in="Sinraptor" out="Allosaurus">
1181 <CGENUS name="Sinraptor"/>
1182 <CGENUS name="Szechuanosaurus"/>
1183 <CGENUS name="Yangchuanosaurus"/>
1185 <CLINK name="Allosauridae"/>
1190 <P header="History"> The taxon Carnosauria once included all large <LINK
1191 content="theropods"/>, from large <LINK content="ceratosaurs"/> to <LINK
1192 content="megalosaurs"/> to <LINK content="tyrannosaurs"/>. More recent
1193 research shows that most of these are more closely allied to other groups.
1194 Today, only the allosaurids and their relatives are considered true
1195 carnosaurs (The precise definition: all animals sharing a more recent
1196 common ancestor with <NOMEN name="Allosaurus"/> than with <LINK
1197 content="modern birds"/>). </P>
1199 <P header="Ornate Killers"> Many carnosaurs bore crests atop their heads.
1200 The primitive forms <NOMEN name="Monolophosaurus"/> and <NOMEN
1201 name="Cryolophosaurus"/> (one of the few dinosaurs from Antarctica) had
1202 ridges along the tops of their snouts. In <NOMEN name="Cryolophosaurus"/>
1203 this culminated in a large, vertical crest. <NOMEN name="Allosaurus"/> had
1204 paired crests above the eyes, especially prominent in
1205 <NOMEN name="A. fragilis"/>. </P>
1207 <P header="An Early End"> Carnosaurs did not survive to the end of the
1208 <LINK content="Mesozoic"/>. They may have been out-competed by <LINK
1209 content="abelisaurids"/> and <LINK content="tyrannosaurids"/>. But in
1210 their heyday they included the largest known land predators of all time.
1215 <TAXON name="Centrosaurinae" nickname="Dinosaurian Rhinoceri">
1216 <WORD key="1" content="horned, frilled, spike, nose, snout"/>
1218 <CLADE name="Centrosaurinae" in="Centrosaurus" out="Ceratops" silhouette="centrosaurinae">
1219 <CGENUS name="Avaceratops" incertae="1"/>
1220 <CLADE name="Centrosaurini">
1221 <CGENUS name="Centrosaurus"/>
1222 <CGENUS name="Styracosaurus" silhouette="styracosaurus"/>
1224 <CLADE name="Pachyrhinosaurini">
1225 <CGENUS name="Brachyceratops"/>
1226 <CGENUS name="Monoclonius"/>
1228 <CGENUS name="Einiosaurus" silhouette="einiosaurus"/>
1229 <CLADE silhouette="achelousaurus-pachyrhinosaurus">
1230 <CGENUS name="Achelousaurus"/>
1231 <CGENUS name="Pachyrhinosaurus"/>
1237 <CLADOGRAM alternate="1">
1238 <REFER page="Coronosauria"/>
1241 <P header="Physical Characteristics"> One of the two main lineages of ceratopsids (a.k.a. horned
1242 dinosaurs"), most centrosaurines bore large horns on their noses. Unlike
1243 most members of their sister group, the <LINK content="ceratopsines"/>,
1244 their neck frills tended to be relatively short, although often
1245 accentuated by two large spikes at the top, or spikes all along the rim of
1246 the frill as in <NOMEN name="Styracosaurus"/>. Their snouts were also
1249 <P> The advanced pachyrhinosaurins had a large, blunt bony growth in place
1250 of the nasal horn. This may have formed the core of a horny pad in life,
1251 or possibly the core of a gigantic nasal horn. </P>
1255 <TAXON name="Ceratopsia" nickname="Frilled Dinosaurs">
1256 <WORD key="1" content="frilled, horned, protoceratopsian"/>
1257 <WORD essay="1" content="the horned & frilled dinosaurs"/>
1259 <CLADE name="Ceratopsia" in="Ceratops" out="Pachycephalosaurus" silhouette="ceratopsia">
1260 <AUTHOR name="Marsh" year="1890"/>
1261 <CSYNONYM name="Ceratopia"/>
1263 <NOMEN name="Ceratops"/>' <LOW>taxon</LOW>
1266 <TIME value="Aptian"/>
1267 <PLACE name="Utah"/>
1270 <TIME section="early" value="Cenomanian"/>
1271 <PLACE name="Utah"/>
1272 <REMAINS content="teeth"/>
1275 <PLACE name="England"/>
1278 <CGENUS name="Echizensaurus" incertae="1"/>
1279 <CLADE name="Psittacosauria" in="Psittacosaurus" out="Ceratops">
1281 <NOMEN name="Psittacosaurus"/>' <LOW>taxon</LOW>
1284 <PLACE name="China"/>
1285 <TIME section="middle" value="Barremian"/>
1287 <CGENUS name="Psittacosaurus"/>
1289 <CLADE name="Neoceratopsia" in="Ceratops" out="Psittacosaurus" silhouette="neoceratopsia">
1290 <AUTHOR name="Sereno" year="1986"/>
1294 <UNNAMED indet="1" cf="Leptoceratops">
1295 <TIME value="Albian"/>
1296 <PLACE name="Australia"/>
1297 <REMAINS museum="NMV" id="P186385" content="ulna"/>
1300 <TIME section="middle" value="Campanian"/>
1301 <PLACE name="Alberta"/>
1304 <TIME section="early" value="Aptian"/>
1305 <TIME section="middle" value="Aptian"/>
1306 <PLACE name="Maryland"/>
1307 <REMAINS content="tooth"/>
1309 <UNNAMED cf="Leptoceratops">
1310 <TIME section="middle-late" value="Campanian"/>
1311 <PLACE name="Alberta"/>
1312 <REMAINS content="dentaries"/>
1314 <CGENUS name="Graciliceratops" incertae="1"/>
1315 <CGENUS name="Leptoceratops" incertae="1"/>
1316 <CGENUS name="Udanoceratops" incertae="1"/>
1317 <CGENUS name="Chaoyangsaurus" q="1"/>
1318 <CGENUS name="Archaeoceratops"/>
1319 <CGENUS name="Kulceratops" q="1"/>
1321 <CGENUS name="Asiaceratops"/>
1322 <CGENUS name="Microceratops"/>
1323 <CLINK name="Coronosauria"/>
1329 <P> This group of herbivores contains the frilled <LINK
1330 content="dinosaurs"/>, including the horned dinosaurs. Like many other
1331 groups of <LINK content="Late Cretaceous"/> dinosaurs, they inhabited only Asia and North
1334 <P header="Evolution"> <NOMEN name="Psittacosaurus"/> is the most primitive known
1335 ceratopsian. The back of its skull hints at the giant neck frill of later
1336 ceratopsians. Its powerful parrot-like beak, for which the genus was named
1337 ("parrot lizard"), features an extra bone. This bone, the rostral bone, is
1338 unique to ceratopsians. </P>
1340 <P> The creatures on this page were all bipedal. From such as these came
1341 the quadrupedal <LINK content="coronosaurs"/>. Coronosaurs were generally
1342 larger, although at least one bipedal ceratopsian (<NOMEN
1343 name="Udanoceratops"/>) grew to a fairly large size. Bipedal ceratopsians
1344 persisted until the end of the <LINK content="Mesozoic"/>, co-existing with
1345 the more advanced <LINK content="ceratopsoids"/>. </P>
1347 <P> (See <LINK content="Ceratopsinae"/> for a discussion on the "s" in
1352 <TAXON name="Ceratopsinae" nickname="Three-Horns">
1353 <WORD key="1" content="horned, frilled"/>
1355 <CLADE name="Ceratopsinae" in="Ceratops" out="Centrosaurus" silhouette="ceratopsinae">
1356 <CSYNONYM name="Ceratopinae"/>
1357 <CSYNONYM name="Chasmosaurinae"/>
1358 <CSYNONYM name="Agathauminae" q="1"/>
1360 <PLACE name="U.S.A."/>
1362 <CGENUS name="Polyonax" incertae="1"/>
1363 <CGENUS name="Ugrosaurus" incertae="1"/>
1364 <CLADE name="Chasmosaurini">
1365 <CSYNONYM name="Ceratopsini" q="1"/>
1366 <CSYNONYM name="Ceratopini" q="1"/>
1367 <CGENUS name="Ceratops" incertae="1" q="1"/>
1368 <CGENUS name="Chasmosaurus"/>
1369 <CGENUS name="Pentaceratops"/>
1372 <CGENUS name="Anchiceratops"/>
1374 <CGENUS name="Arrhinoceratops"/>
1376 <CGENUS name="Torosaurus"/>
1377 <CLADE silhouette="diceratops-triceratops">
1378 <CGENUS name="Diceratops"/>
1379 <CGENUS name="Triceratops"/>
1386 <CLADOGRAM alternate="1">
1387 <REFER page="Coronosauria"/>
1390 <P header="Physical Characteristics"> Unlike their sister group, the <LINK content="centrosaurines"/>,
1391 ceratopsines (a.k.a. chasmosaurines), placed more emphasis on brow horns
1392 than the nasal horn, to the point that some barely had a nasal horn at
1393 all, hence names like <NOMEN name="Arrhinoceratops"/> ("without nose-horn
1394 face") and <NOMEN name="Diceratops"/> ("two-horned face"). </P>
1396 <P> Their neck frills were longer than those of centrosaurines, except in
1397 the lineage leading to <NOMEN name="Triceratops"/>, wherein they became
1398 short and completely solid, with no parietal fenestrae. </P>
1400 <P header="A Name Problem"> There has been some disagreement over the name of this group and all
1401 other groups named after the genus <NOMEN name="Ceratops"/>. For years
1402 they have been known as Ceratopsidae, Ceratopsia, etc. Some have pointed
1403 out that this is not correct Greek, and that the "s" should be dropped,
1404 hence Ceratopidae, Ceratopia. But the names with "s" have become deeply
1405 entrenched in <LINK content="dinosaur"/> terminology, and are used on this
1410 <TAXON name="Coelophysoidea" nickname="Early Kink-Snouted Predators" silhouette="coelophysoidea-large">
1411 <WORD key="1" content="spitter, frill, Gojira, Godzilla"/>
1413 <CLADE name="Coelophysoidea" in="Coelophysis" out="Ceratosaurus" silhouette="neotheropoda">
1414 <CSYNONYM name="Podokesauroidea" q="1"/>
1415 <CGENUS name="Camposaurus" incertae="1"/>
1416 <CLADE name="Coelophysidae" in="Coelophysis, Procompsognathus">
1417 <CSYNONYM name="Podokesauridae"/>
1418 <CLADE name="Procompsognathinae" in="Procompsognathus" out="Coelophysis">
1419 <CSYNONYM name="Segisaurinae"/>
1420 <CGENUS name="Procompsognathus"/>
1421 <CGENUS name="Segisaurus"/>
1423 <CLADE name="Coelophysinae" in="Coelophysis" out="Procompsognathus">
1424 <CSYNONYM name="Podokesaurinae" q="1"/>
1425 <UNNAMED comment='"Shake-N-Bake"'>
1426 <TIME value="Hettangian"/>
1427 <TIME value="Pliensbachian"/>
1428 <PLACE name="Arizona"/>
1430 <CGENUS name="Eucoelophysis" incertae="1"/>
1431 <CGENUS name="Gojirasaurus" incertae="1" q="1" silhouette="coelophysoidea-large"/>
1432 <CGENUS name="Coelophysis"/>
1433 <CGENUS name="Syntarsus"/>
1434 <CLADE silhouette="coelophysoidea-large">
1435 <CSYNONYM name="Halticosaurini" q="1"/>
1436 <CGENUS name="Dilophosaurus"/>
1437 <CGENUS name="Liliensternus"/>
1443 <CLADOGRAM alternate="1">
1444 <CLADE name="Coelophysoidea">
1445 <CGENUS name="Dilophosaurus"/>
1447 <CGENUS name="Liliensternus"/>
1449 <UNNAMED comment='"Shake-N-Bake"'/>
1450 <CLADE name="Coelophysidae">
1451 <CLADE name="Coelophysinae">
1452 <CGENUS name="Coelophysis"/>
1453 <CGENUS name="Syntarsus"/>
1455 <CLADE name="Procompsognathinae">
1456 <CGENUS name="Procompsognathus"/>
1457 <CGENUS name="Segisaurus"/>
1465 <P header="Strange Jaws"> <ILLO name="coelophysid_skull"/> Coelophysoids were a group of early
1466 <LINK content="neotheropods"/>. Most were characterized by a kink in the
1467 front of the upper snout, similar to the snout kink of the <LINK
1468 content="spinosaurids"/>. (In fact, some have considered spinosaurids to
1469 be late-surviving coelophysoids.) It was once thought that this kink,
1470 which allowed some mobility for the premaxilla, would have weakened the
1471 skull. But it is now known to have been internally strengthened, and ideas
1472 that coelophysoids could not have been true predators have been dismissed.
1475 <P header="Sizes"> <NOMEN name="Coelophysis"/> and the similar <NOMEN name="Syntarsus"/>
1476 and <NOMEN name="Eucoelophysis"/> were medium-small hunters, larger than
1477 the tiny procompsognathines. <NOMEN name="Liliensternus"/>, <NOMEN
1478 name="Dilophosaurus"/>, and <NOMEN name="Gojirasaurus"/> were the largest
1479 coelophysoids, about 15 to 20 feet long. </P>
1483 <TAXON name="Coelurosauria" nickname="Very Advanced Theropods" silhouette="coelurosauria-small">
1484 <WORD key="1" content="coelurosaurian, maniraptoran, bird, avian, origin, feather, feathers, feathered, proto, proto-feather, integument, skin, impressions"/>
1485 <WORD essay="1" content="arctometatarsalian, arctometatarsalians, arctometatarsalian coelurosaurs, ornitholestid, ornitholestids"/>
1487 <CLADE name="Coelurosauria" in="Neornithes" out="Allosaurus" silhouette="coelurosauria-large">
1488 <AUTHOR name="von Huene" year="1914"/>
1489 <AUTHOR type="sensu" name="Gauthier" year="1986"/>
1491 hollow-tailed lizards
1493 <CGENUS name="Chilantaisaurus maortuensis" incertae="1"/>
1494 <CGENUS name="Diplotomodon" q="1" incertae="1"/>
1495 <CGENUS name="Nqwebasaurus" incertae="1"/>
1496 <CGENUS name="Piveteausaurus" incertae="1" silhouette="ornitholestidae"/>
1497 <CGENUS name="Proceratosaurus" incertae="1" silhouette="ornitholestidae"/>
1498 <CGENUS name="Timimus" incertae="1"/>
1499 <UNNAMED comment="basal">
1501 <PLACE name="S. Africa"/>
1504 <TIME value="Aptian"/>
1505 <TIME value="Albian"/>
1506 <PLACE name="Maryland"/>
1508 <UNNAMED comment="small, big-toothed" silhouette="coelurosauria-small">
1509 <TIME value="Kimmeridgian" section="latest"/>
1510 <TIME value="Tithonian" section="earliest"/>
1511 <PLACE name="Germany"/>
1513 <CGENUS name="Gasosaurus" q="1"/>
1515 <CGENUS incertae="1" name="Bagaraatan"/>
1516 <CGENUS name="Deltadromeus"/>
1517 <CGENUS name="Dryptosaurus"/>
1518 <CGENUS incertae="1" name="Shanyangosaurus"/>
1519 <CLADE name="Maniraptoriformes" in="Neornithes, Ornithomimus">
1520 <MEANING>maniraptor forms</MEANING>
1521 <AUTHOR name="Holtz" year="1996"/>
1522 <CSYNONYM name="Deinonychosauria" sensu="Sereno" q="1"/>
1523 <CSYNONYM name="Manuraptoriformes"/>
1524 <CSYNONYM name="Maniraptora" sensu="Holtz" year="1994"/>
1525 <CSYNONYM name="Bullatosauria" q="1"/>
1526 <CSYNONYM name="Tyrannoraptora" q="1">
1527 <AUTHOR name="Sereno" year="1999"/>
1529 <UNNAMED indet="1" comment="deinonychosaur or troodontid" silhouette="deinonychosauria">
1530 <TIME value="Bathonian"/>
1531 <PLACE name="England"/>
1532 <REMAINS content="teeth"/>
1535 <TIME value="Valanginian" q="1"/>
1536 <TIME value="Hauterivian" q="1"/>
1537 <PLACE name="Thailand"/>
1538 <REMAINS content="metatarsus, other postcranial bones"/>
1540 <CGENUS name="Araucanoraptor" incertae="1" silhouette="deinonychosauria"/>
1541 <CGENUS name="Archaeornithoides" incertae="1" silhouette="maniraptora"/>
1542 <CGENUS name="Aristosuchus sp." incertae="1" silhouette="coelurosauria-small" q="1"/>
1543 <CGENUS name="Arkansaurus" incertae="1" silhouette="ornithomimosauria"/>
1544 <CGENUS name="Elopteryx" incertae="1" silhouette="maniraptora"/>
1545 <CGENUS name="Koparion" incertae="1" silhouette="coelurosauria-small"/>
1546 <CGENUS name="Ornithomimus sp." incertae="1"/>
1547 <CGENUS name="Paronychodon" incertae="1" silhouette="deinonychosauria"/>
1548 <CGENUS name="Phaedrolosaurus" incertae="1"/>
1549 <CGENUS name="Ricardoestesia" incertae="1" silhouette="maniraptora"/>
1550 <CGENUS name="Nedcolbertia" q="1"/>
1551 <CGENUS name="Ornitholestes" silhouette="ornitholestidae" q="1"/>
1552 <CGENUS name="Santanaraptor" incertae="1" q="1"/>
1553 <CGENUS name="Scipionyx" silhouette="coelurosauria-small" q="1"/>
1554 <CLADE name="Avimimidae" incertae="1" silhouette="avimimidae">
1555 <CGENUS name="Avimimus"/>
1556 <CGENUS name="Kakuru" q="1"/>
1558 <TIME section="middle-late" value="Campanian"/>
1559 <PLACE name="Alberta"/>
1562 <CLADE name="Coeluridae" silhouette="coelurosauria-small" q="1">
1564 <PLACE name="Mongolia"/>
1565 <REMAINS museum="ZPAL" id="MgD-I/99"/>
1567 <CGENUS name="Calamosaurus" q="1"/>
1568 <CGENUS name="Coelurus"/>
1570 <CLADE name="Compsognathidae" silhouette="coelurosauria-small" q="1">
1571 <CSYNONYM name="Sinosauropterygidae"/>
1573 <!--Romualdo Member, Santana Formation-->
1574 <!--Martill, Frey, Sues & Cruickshank, 2000-->
1575 <PLACE name="Brazil"/>
1576 <TIME value="Aptian"/>
1577 <REMAINS museum="SMNK" id="2349 PAL" content="partial ilium, pubis, ischium, femora, distal ends of fibula and tibia, sacral vertebrae, ?intestinal track, ?postpubic air sac"/>
1579 <CGENUS name="Aristosuchus" q="1"/>
1580 <CGENUS name="Compsognathus"/>
1581 <CGENUS name="Sinosauropteryx"/>
1583 <CLINK name="Troodontidae" incertae="1"/>
1584 <CLINK name="Tyrannosauroidea"/>
1585 <CLADE name="Arctometatarsalia" in="Ornithomimus" out="Neornithes">
1586 <MEANING>pinched metatarsals</MEANING>
1587 <AUTHOR name="Holtz" year="1994"/>
1588 <AUTHOR type="emended" year="1996"/>
1589 <CSYNONYM name="Ornithomimosauria" sensu="Sereno"/>
1590 <CLINK name="Ornithomimosauria"/>
1592 <CLADE name="Maniraptora" in="Neornithes" out="Ornithomimus" silhouette="maniraptora">
1593 <AUTHOR name="Gauthier" year="1986"/>
1594 <AUTHOR type="sensu" name="Holtz" year="1996"/>
1596 <LOW>big-</LOW>handed raiders
1598 <CSYNONYM name="Manuraptora"/>
1599 <UNNAMED comment="(oviraptorosaurian?)">
1600 <TIME value="Aptian"/>
1601 <PLACE name="Australia"/>
1602 <REMAINS museum="NMV" id="P186386" content="right surangular (lower jaw part)"/>
1603 <REMAINS museum="NMV" id="P186302" content="vertebra" q="1"/>
1606 <TIME value="K" q="1"/>
1607 <PLACE name="Mongolia"/>
1608 <REMAINS content="feather impression"/>
1611 <TIME value="Hauterivian"/>
1612 <PLACE name="Russia"/>
1613 <REMAINS content="feather impression"/>
1616 <TIME value="Hauterivian" q="1"/>
1617 <PLACE name="Spain"/>
1618 <REMAINS content="feather impression"/>
1621 <TIME value="Hauterivian" q="1"/>
1622 <PLACE name="Lebanon"/>
1623 <REMAINS content="feather impression"/>
1626 <TIME value="Aptian"/>
1627 <PLACE name="Brazil"/>
1628 <REMAINS content="feather impression"/>
1631 <TIME value="Aptian" q="1"/>
1632 <TIME value="Albian" q="1"/>
1633 <PLACE name="Spain"/>
1634 <REMAINS content="feather impression"/>
1637 <TIME value="Aptian" q="1"/>
1638 <PLACE name="Mongolia"/>
1639 <REMAINS content="feather impression"/>
1642 <TIME value="Albian" q="1"/>
1643 <PLACE name="Australia"/>
1644 <REMAINS content="feather impression"/>
1646 <CGENUS name="Palaeopteryx" q="1" incertae="1"/>
1647 <CGENUS name="Protarchaeopteryx" incertae="1"/>
1648 <CLADE name="Yandangornithiformes" incertae="1">
1649 <CGENUS name="Yandangornis"/>
1651 <CLADE in="Neornithes, Oviraptor">
1652 <CSYNONYM name="Maniraptora" sensu="Sereno"/>
1653 <CLADE in="Oviraptor" out="Neornithes">
1654 <CSYNONYM name="Oviraptorosauria" sensu="Currie, Padian" year="1997"/>
1656 <TIME section="late" value="LJ"/>
1657 <PLACE name="U.S.A."/>
1658 <REMAINS content="neck vertebrae"/>
1661 <PLACE name="Brazil"/>
1662 <TIME value="Albian"/>
1664 <UNNAMED indet="1" q="1">
1666 <PLACE name="Argentina"/>
1667 <REMAINS content="neck vertebra"/>
1669 <CGENUS name="Microvenator"/>
1670 <CLINK name="Therizinosauria"/>
1673 <REMAINS content="jaws"/>
1674 <PLACE name="Kazakhstan"/>
1677 <PLACE name="U.S.A."/>
1678 <TIME value="LJ" section="late"/>
1679 <REMAINS content="caudal vertebra"/>
1681 <CGENUS name="Caudipteryx" q="1"/>
1682 <CLINK name="Oviraptorosauria"/>
1685 <CLADE name="Paraves" in="Neornithes" out="Oviraptor" silhouette="paraves">
1686 <AUTHOR name="Sereno"/>
1688 beside <LINK content="Aves"/>
1691 <TIME value="Kimmeridgian"/>
1692 <PLACE name="Colorado"/>
1693 <REMAINS content="disarticulated bones"/>
1696 <PLACE name="Argentina"/>
1697 <TIME value="Cenomanian" q="1"/>
1698 <REMAINS content="dorsal vertebra, 3 caudal centra, complete rib, partial metatrasal II, manual & pedal unguals"/>
1700 <UNNAMED comment="large" silhouette="paraves-flightless">
1701 <PLACE name="Argentina"/>
1702 <TIME value="Cenomanian" q="1"/>
1703 <REMAINS content="left ungual phalanx (digit II), right metatarsal II, etc."/>
1705 <CGENUS name="Adasaurus" incertae="1"/>
1706 <CGENUS name="Hulsanpes" incertae="1"/>
1707 <CGENUS name="Megaraptor" incertae="1" silhouette="paraves-flightless"/>
1708 <CLADE name="Eumaniraptora" in="Neornithes, Deinonychus">
1709 <AUTHOR name="Padian, Hutchinson, Holtz" year="1998"/>
1713 <CSYNONYM name="Eumanuraptora"/>
1714 <CLINK name="Deinonychosauria"/>
1715 <CLINK name="Avialae"/>
1724 <CLADOGRAM alternate="1">
1725 <CLADE name="Maniraptoriformes">
1726 <CLADE name="Maniraptora"/>
1727 <CLADE name="Arctometatarsalia">
1728 <CLADE name="Tyrannosauroidea"/>
1729 <CLADE name="Bullatosauria" in="Ornithomimus, Troodon">
1730 <AUTHOR name="Holtz" year="1994"/>
1731 <AUTHOR type="emended" year="1996"/>
1732 <MEANING>pneumatic <LOW>braincase</LOW> lizards</MEANING>
1733 <CLADE name="Troodontidae"/>
1734 <CLADE name="Ornithomimosauria"/>
1739 <CLADOGRAM alternate="1">
1740 <CLADE name="Tyrannoraptora" in="Neornithes, Tyrannosaurus">
1744 <CLADE name="Tyrannosauroidea"/>
1746 <CGENUS name="Scipionyx"/>
1747 <CLADE name="Compsognathidae"/>
1748 <CLADE name="Maniraptoriformes">
1749 <CLADE name="Ornithomimosauria"/>
1750 <CLADE name="Maniraptora">
1752 <CLADE name="Therizinosauria"/>
1754 <CGENUS name="Caudipteryx"/>
1755 <CLADE name="Oviraptorosauria"/>
1758 <CLADE name="Paraves">
1759 <CLADE name="Eumaniraptora">
1760 <CLADE name="Avialae"/>
1761 <CLADE name="Deinonychosauria">
1762 <CLADE name="Dromaeosauridae"/>
1763 <CLADE name="Troodontidae"/>
1772 <CLADOGRAM alternate="1">
1773 <CLADE name="Maniraptoriformes">
1774 <CLADE name="Arctometatarsalia">
1775 <CSYNONYM name="Ornithomimosauria" sensu="Sereno"/>
1776 <CLADE name="Therizinosauria" q="1"/>
1777 <CLADE name="Ornithomimoidea" sensu="Sereno">
1778 <CLADE name="Alvarezsauria">
1779 <CSYNONYM name="Alvarezsauridae" sensu="Sereno"/>
1781 <CLADE name="Ornithomimosauria">
1782 <CSYNONYM name="Ornithomimidae" sensu="Sereno"/>
1786 <CLADE name="Maniraptora">
1787 <CLADE name="Tyrannoraptora">
1788 <CLADE name="Tyrannosauroidea"/>
1790 <CSYNONYM name="Maniraptora" sensu="Sereno"/>
1792 <CGENUS name="Caudipteryx"/>
1793 <CLADE name="Oviraptorosauria"/>
1795 <CLADE name="Paraves">
1796 <CLADE name="Eumaniraptora">
1797 <CLADE name="Avialae"/>
1798 <CLADE name="Deinonychosauria">
1799 <CLADE name="Dromaeosauridae"/>
1800 <CLADE name="Troodontidae"/>
1809 <CLADOGRAM alternate="1">
1811 <CLADE name="Compsognathia">
1813 <NOMEN name="Compsognathus"/>' <LOW>taxon</LOW>
1815 <CSYNONYM name="Sinosauropterygiformes" q="1"/>
1816 <CGENUS name="Scipionyx"/>
1817 <CLADE name="Compsognathidae"/>
1818 <CLADE name="Ornitholestidae">
1819 <CGENUS name="Ornitholestes"/>
1820 <CGENUS name="Piveteausaurus" q="1"/>
1821 <CGENUS name="Proceratosaurus"/>
1824 <CLADE name="Maniraptoriformes">
1825 <CLADE name="Maniraptora"/>
1826 <CLADE name="Arctometatarsalia">
1827 <CLADE name="Tyrannosauroidea"/>
1828 <CLADE name="Bullatosauria">
1829 <CLADE name="Troodontidae"/>
1831 <CLADE name="Ornithomimosauria">
1832 <CGENUS name="Pelecanimimus"/>
1833 <CLADE name="Ornithomimoidea"/>
1835 <CLADE name="Therizinosauria">
1836 <CGENUS name="Harpymimus" q="1"/>
1838 <CLADE name="Therizinosauroidea"/>
1847 <CLADOGRAM alternate="1">
1848 <CLADE name="Maniraptora">
1849 <CLADE name="Paraves"/>
1851 <CLADE name="Troodontidae"/>
1853 <CLADE name="Oviraptorosauria"/>
1854 <CLADE name="Therizinosauria"/>
1859 <CLADOGRAM alternate="1">
1860 <CLADE name="Tyrannoraptora">
1861 <CLADE name="Tyrannosauroidea"/>
1863 <CLADE name="Compsognathidae"/>
1864 <CLADE name="Maniraptoriformes">
1865 <CLADE name="Ornithomimosauria"/>
1866 <CLADE name="Maniraptora">
1867 <CLADE name="Oviraptorosauria"/>
1868 <CLADE name="Paraves">
1869 <CLADE name="Troodontidae"/>
1870 <CLADE name="Eumaniraptora">
1871 <CLADE name="Deinonychosauria"/>
1872 <CLADE name="Avialae"/>
1880 <CLADOGRAM alternate="1">
1881 <CLADE name="Paraves">
1882 <CGENUS name="Dromaeosaurus"/>
1883 <CLADE name="Eumaniraptora">
1884 <CLADE name="Avialae"/>
1885 <CLADE name="Deinonychosauria">
1886 <CGENUS name="Deinonychus"/>
1887 <CGENUS name="Saurornithoides"/>
1888 <CGENUS name="Velociraptor"/>
1894 <P header="History">Coelurosauria once included all the small <LINK content="theropods"/>.
1895 It was the sister group to <LINK content="Carnosauria"/>, which included
1896 all the big theropods. This system of theropod classification has become
1897 very much outdated, but the original names are still kept for certain
1898 actual groups. If the more primitive forms of the old Coelurosauria are
1899 excluded and a few other forms are added (including <LINK
1900 content="birds"/>), they do form a monophyletic group. Interestingly,
1901 this group that once contained only small theropods now includes <NOMEN
1902 name="Tyrannosaurus rex"/>, one of the largest theropods, indeed, one of
1903 the largest land predators of all time.</P>
1905 <P>Coelurosaurs are an enormously diverse group. They include <LINK
1906 content="fast runners"/>, <LINK content="night prowlers"/>, <LINK
1907 content="gigantic predators"/>, <LINK content="toothless weirdos"/>, <LINK
1908 content="vicious carnivores"/>, and the incredibly varied birds. </P>
1910 <P header="Integument"> Skin impressions are known from several coelurosaurs.
1911 A partial impression, possibly from the tail of a <LINK content="tyrannosaur"/>
1912 shows scales like those seen in other dinosaurs. All other
1913 coelurosaur skin impressions, such as those of <NOMEN name="Sinosauropteryx"/>,
1914 <NOMEN name="Protarchaeopteryx"/>, <NOMEN name="Caudipteryx"/>, <NOMEN
1915 name="Beipiaosaurus"/>, <NOMEN name="Sinornithosaurus"/>, and birds like
1916 <NOMEN name="Archaeopteryx"/>,
1917 show feathers or feather-like integument. Such integument may have been
1918 present in the earliest coelurosaurs, then lost in gigantic forms, much as
1919 gigantic <LINK content="mammals"/> tend not to have hair. </P>
1921 <P header="Classification and Characters"> The advanced coelurosaurs make up
1922 Maniraptoriformes. All
1923 maniraptoriforms sharing a more recent ancestor with <NOMEN
1924 name="Ornithomimus"/> than with birds are arctometatarsalians. All sharing
1925 a more recent ancestor with birds than with <NOMEN name="Ornithomimus"/>
1926 are maniraptors. It is not certain whether some groups (coelurids,
1927 compsognathids, ornitholestids, etc.) belong to one of these two groups
1928 or fall outside of Maniraptoriformes. </P>
1930 <P> Arctometatarsalia originally included <LINK content="caenagnathids"/>,
1931 avimimids, tyrannosauroids, troodontids, and ornithomimosaurs. It was
1932 named for the arctometatarsalian foot of these animals, wherein the
1933 middle metatarsal is pinched at the top. This trait, an adaptation for
1934 running, is now thought to have evolved separately in caenagnathids
1935 and possibly in all five of the groups. <LINK content="Mononykines"/>
1936 have an extreme version of this feature. </P>
1938 <P> <ILLO name="dromaeosaurid_pes"/> <LINK content="Avialae"/> includes all
1939 animals that share more recent ancestry with birds than with
1940 deinonychosaurs. Several primitive avialans have been found with
1941 dromaeosaurid-like "sickle claws" (a hyperextendable second digit
1942 with a large, very curved claw) on their feet, including <NOMEN
1943 name="Rahonavis"/> and the <LINK content="enantiornithean"/> <NOMEN
1944 name="Vorona"/>. It was also realized not long ago that the
1945 "first bird", <NOMEN name="Archaeopteryx"/>, had a hyperextendable
1946 second toe. This trait may be a basal trait for all paravians. </P>
1950 <TAXON name="Coronosauria" nickname="Horned Dinosaurs & Kin">
1951 <WORD key="1" content="frilled, horned"/>
1953 <CLADE name="Coronosauria" in="Triceratops, Protoceratops" silhouette="coronosauria">
1957 <CGENUS name="Bagaceratops"/>
1958 <CGENUS name="Breviceratops"/>
1959 <CGENUS name="Protoceratops"/>
1960 <CLADE name="Ceratopsoidea" in="Ceratops, Montanoceratops" silhouette="ceratopsoidea">
1961 <CSYNONYM name="Ceratopoidea"/>
1962 <CGENUS name="Montanoceratops"/>
1963 <CLADE name="Ceratopsomorpha" in="Ceratops, Zuniceratops" silhouette="ceratopsomorpha">
1965 <NOMEN name="Ceratops"/> forms
1967 <CGENUS name="Zuniceratops"/>
1969 <CGENUS name="Turanoceratops"/>
1970 <CLADE name="Ceratopsidae" in="Ceratops, Centrosaurus">
1971 <CSYNONYM name="Agathaumidae"/>
1972 <CSYNONYM name="Ceratopidae"/>
1973 <CGENUS name="Agathaumas" incertae="1"/>
1974 <CGENUS name="Dysganus" incertae="1"/>
1975 <CLINK name="Centrosaurinae"/>
1976 <CLINK name="Ceratopsinae"/>
1983 <CLADOGRAM alternate="1">
1984 <CLADE name="Coronosauria">
1985 <CLADE name="Ceratopsoidea"/>
1986 <CLADE name="Protoceratopsidae" in="Protoceratops" out="Ceratops">
1987 <CGENUS name="Bagaceratops"/>
1988 <CGENUS name="Breviceratops"/>
1989 <CGENUS name="Protoceratops"/>
1993 <CLADOGRAM alternate="1">
1994 <CLADE name="Ceratopsidae">
1995 <CSYNONYM name="Ceratopsoidea"/>
1996 <CSYNONYM name="Ceratopsomorpha"/>
1997 <CLADE name="Centrosaurinae">
1998 <CGENUS name="Montanoceratops"/>
1999 <CLADE comment="other centrosaurines"/>
2001 <CLADE name="Ceratopsinae">
2002 <CGENUS name="Zuniceratops"/>
2003 <CLADE comment="other ceratopsines"/>
2007 <CLADOGRAM alternate="1">
2008 <CLADE name="Ceratopsoidea">
2009 <CLADE name="Ceratopsomorpha"/>
2010 <CLADE name="Leptoceratopsidae">
2011 <CSYNONYM name="Leptoceratopidae"/>
2012 <CGENUS name="Leptoceratops"/>
2013 <CGENUS name="Montanoceratops"/>
2017 <CLADOGRAM alternate="1">
2018 <CLADE in="Avaceratops, Chasmosaurus, Centrosaurus">
2019 <CSYNONYM name="Ceratopsidae" sensu="Penkalski, Dodson" year="1999"/>
2020 <CGENUS name="Avaceratops"/>
2021 <CLADE name="Ceratopsidae"/>
2025 <P header="Characteristics"> This group includes all of the quadrupedal <LINK
2026 content="ceratopsians"/>. Coronosaurs tend to be larger and have larger
2027 neck frills than more primitive ceratopsians. There has been much dispute
2028 as to whether the front limbs of coronosaurs were held fully erect or
2029 sprawling to various degrees. An intermediate posture seems most likely. </P>
2031 <P> The most primitive coronosaurs, like the well-known <NOMEN
2032 name="Protoceratops"/>, lacked horns, although they bore small bumps on
2033 their noses. <NOMEN name="Montanoceratops"/>, the most primitive known
2034 ceratopsoid, possessed a true horn on its nose. In addition to the nasal
2035 horn ceratopsomorphs like <NOMEN name="Zuniceratops"/> possessed brow
2036 horns above their eyes. </P>
2038 <P> The function of the neck frills in these and other ceratopsians is not
2039 certain. They may have borne colorful displays, protected the neck from
2040 predators, anchored powerful cheek muscles, or performed a combination of
2041 these functions. In <NOMEN name="Protoceratops"/>, one gender (male?) has
2042 a much wider frill than the other, supporting the idea that these were
2043 used as sexual displays. </P>
2045 <P header="The Mighty Ceratopsids"> Hailing from the very latest stretch of
2046 the <LINK content="Mesozoic Era"/>, ceratopsids were the pinnacle of
2047 <LINK content="ceratopsian"/> evolution. They included some of the very
2049 content="ornithischians"/>, such as the mighty <NOMEN
2050 name="Triceratops"/>. They are only known from North America (unless the
2051 Asian <NOMEN name="Turanoceratops"/> is really a ceratopsid). </P>
2053 <P> Skin impressions are known from both centrosaurine ceratopsids (<NOMEN
2054 name="Centrosaurus"/>) and ceratopsine ceratopsids (<NOMEN
2055 name="Chasmosaurus"/>). They both show large, flat scales interspersed
2056 with larger, round tubercles. </P>
2058 <P header="Classification"> The genera listed here, plus other <LINK content="neoceratopsians"/>
2059 were once grouped in the family Protoceratopsidae (=Protoceratopidae),
2060 since they all had claws instead of hooves. Most now consider this a
2061 paraphyletic (and hence invalid) grouping. There may, however, be a
2062 monophyletic (hence valid) group of basal coronosaurs which would be
2063 termed Protoceratopsidae. </P>
2067 <TAXON name="Crocodylomorpha" nickname='"Crocs"' simple="1">
2068 <WORD key="1" essay="1" content="crocodile, crocodilian"/>
2070 <CLADE name="Crocodylomorpha" silhouette="crocodylomorpha">
2071 <AUTHOR name="Walker" year="1970"/>
2073 <NOMEN nolink="1" name="Crocodylus"/> <LOW>(crocodile)</LOW> forms
2075 <CLADE name="Sphenosuchidae" extinct="1"/>
2076 <CLADE name="Crocodyliformes">
2078 <NOMEN nolink="1" name="Crocodylus"/> <LOW>(crocodile)</LOW> forms
2080 <CSYNONYM name="Crocodylia" sensu="lato"/>
2081 <CGENUS name="Eopneumatosuchus" extinct="1"/>
2082 <CGENUS name="Gobiosuchus" extinct="1"/>
2083 <CGENUS name="Orthosuchus" extinct="1"/>
2084 <CLADE name="Protosuchidae" extinct="1"/>
2085 <CLADE name="Mesoeucrocodylia">
2087 intermediate true crocodylians
2089 <UNNAMED comment="Fruita"/>
2090 <CGENUS name="Mahajangasuchus" incertae="1"/>
2091 <CGENUS name="Baurusuchus" extinct="1"/>
2092 <CGENUS name="Notosuchus" extinct="1"/>
2094 <CGENUS name="Libycosuchus" extinct="1"/>
2096 <CGENUS name="Sebecus" extinct="1"/>
2098 <CGENUS name="Araripesuchus" extinct="1"/>
2099 <CLADE name="Neosuchia">
2100 <CLADE name="Atoposauridae" extinct="1"/>
2102 <CGENUS name="Bernissartia" extinct="1"/>
2103 <CGENUS name="Goniopholis" extinct="1"/>
2105 <CGENUS name="Eutretauranosuchus" extinct="1"/>
2107 <CLADE name="Dyrosauridae" extinct="1"/>
2109 <CLADE name="Pholidosaurus" extinct="1"/>
2110 <CLADE name="Thalattosuchia" extinct="1">
2111 <CGENUS name="Pelagosaurus" extinct="1"/>
2113 <CLADE name="Metrorhynchidae" extinct="1"/>
2114 <CLADE name="Teleosauridae" extinct="1"/>
2120 <CLADE name="Eusuchia">
2121 <CGENUS name="Hylaeochampsa" extinct="1"/>
2122 <CLADE name="Crocodylia" crown="1">
2124 <NOMEN nolink="1" name="Crocodylus"/>' <LOW>(crocodile) taxon</LOW>
2126 <CLADE name="Gavialoidea" in="Gavialis" out="Alligator, Crocodylus">
2127 <CGENUS name="Thoracosaurus" extinct="1"/>
2129 <CGENUS name="Eogavialis" extinct="1"/>
2131 <CGENUS name="Gryposuchus" extinct="1"/>
2132 <CLADE name="Gavialidae" crown="1" content="gavials (or gharials)"/>
2137 <CGENUS name="Borealosuchus" extinct="1"/>
2139 <CGENUS name="Pristichampus" extinct="1"/>
2140 <CLADE name="Brevirostres" in="Alligator, Crocodylus">
2144 <CLADE name="Alligatoroidea" in="Alligator" out="Crocodylus, Gavialis">
2145 <CGENUS name="Deinosuchus" extinct="1"/>
2146 <CGENUS name="Leidyosuchus" extinct="1"/>
2148 <CGENUS name="Diplocynodon" extinct="1"/>
2149 <CLADE name="Alligatoridae" crown="1" content="alligators, caimans, nettosuchines, Purussaurus"/>
2152 <CLADE name="Crocodyloidea" in="Crocodylus" out="Alligator, Gavialis">
2153 <UNNAMED comment="Dormaal"/>
2154 <CGENUS name="Prodiplocynodon" extinct="1"/>
2155 <CGENUS name="Asiatosuchus germanicus" extinct="1"/>
2157 <CGENUS name='"Crocodylus" affinis' extinct="1"/>
2159 <CGENUS name="Brachyuranochampsa" extinct="1"/>
2160 <CGENUS name='"Crocodylus" acer' extinct="1"/>
2161 <CLADE name="Crocodylidae" crown="1" content="crocodiles"/>
2180 <P> Crocodylomorphs originated around the same time as the <LINK
2181 content="dinosaurs"/>. They were the only <LINK content="pseudosuchians"/>
2182 to survive the <LINK content="Triassic"/>, and survive to the present day
2183 in the form of crocodylians. Of all living animals, crocodylians are the
2184 closest relatives to dinosaurs (excluding <LINK content="modern birds"/>,
2185 which <B>are</B> dinosaurs). Unlike other living <LINK
2186 content="sauropsids"/> (except for birds), crocodylians have a
2187 four-chambered heart and a semi-upright stance. </P>
2189 <P> Some "primitive" crocodylomorphs may have been more active and agile
2190 than today's crocodylians, which have evolved a relatively sluggish
2195 <TAXON name="Deinonychosauria" nickname="Sickle-Clawed Killers">
2196 <WORD key="1" content="dromy, dromies, raptors, 'raptors, sickle, switchblade, claw"/>
2197 <WORD essay="1" content="vicious carnivores"/>
2199 <CLADE name="Deinonychosauria" in="Deinonychus" out="Neornithes" silhouette="deinonychosauria">
2200 <AUTHOR name="Colbert, Russell" year="1969"/>
2201 <AUTHOR type="sensu" name="Gauthier" year="1986"/>
2202 <AUTHOR type="emended" name="Currie, Padian" year="1997"/>
2204 <NOMEN name="Deinonychus"/> lizards
2207 <TIME value="Albian"/>
2208 <PLACE name="Utah"/>
2211 <TIME value="K" q="1"/>
2212 <PLACE name="N. America"/>
2213 <REMAINS content="teeth"/>
2215 <UNNAMED indet="1" q="1">
2216 <TIME value="Aptian"/>
2217 <TIME value="Albian"/>
2218 <PLACE name="Australia"/>
2219 <REMAINS content="teeth"/>
2222 <TIME value="Maastrichtian" section="late"/>
2223 <PLACE name="France"/>
2224 <REMAINS content="tooth"/>
2227 <PLACE name="Africa"/>
2229 <UNNAMED comment="medium-sized">
2230 <PLACE name="Mongolia"/>
2232 <UNNAMED cf="Archaeoraptor">
2233 <TIME value="Barremian"/>
2234 <PLACE name="China"/>
2235 <REMAINS content="tail, hindlimbs"/>
2237 <CGENUS incertae="1" name="Achillobator"/>
2238 <CGENUS incertae="1" q="1" name="Euronychodon"/>
2239 <CGENUS incertae="1" q="1" name="Kitadanisaurus"/>
2240 <CGENUS incertae="1" q="1" name="Koreanosaurus"/>
2241 <CGENUS name="Nuthetes" incertae="1"/>
2242 <CGENUS incertae="1" q="1" name="Ornithodesmus"/>
2243 <CGENUS incertae="1" name="Pyroraptor"/>
2244 <CGENUS incertae="1" name="Utahraptor"/>
2245 <CGENUS incertae="1" name="Variraptor"/>
2246 <CGENUS name="Sinornithosaurus"/>
2247 <CLADE name="Dromaeosauridae" in="Dromaeosaurus, Velociraptor">
2248 <CSYNONYM name="Ornithodesmidae" q="1"/>
2249 <CLADE name="Dromaeosaurinae" in="Dromaeosaurus" out="Velociraptor">
2250 <CGENUS name="Dromaeosaurus"/>
2252 <CLADE name="Velociraptorinae" in="Velociraptor" out="Dromaeosaurus">
2253 <CGENUS name="Deinonychus"/>
2254 <CGENUS name="Saurornitholestes"/>
2255 <CGENUS name="Velociraptor"/>
2260 <CLADOGRAM alternate="1">
2261 <REFER page="Coelurosauria"/>
2264 <P header="A Deadly Weapon"> <ILLO align="right" name="dromaeosaurid_pes"/> The most striking
2265 feature of the dromaeosaurids was the large second claw of the foot, which
2266 was highly mobile and could swing back and forth, thus giving it the
2267 nickname "switchblade claw" or "sickle claw". Similar claws were present
2268 on the feet of other primitive <LINK content="paravians"/>, as well as
2269 <LINK content="troodontids"/> (which may be paravians) and, to a lesser
2270 extent, <NOMEN name="Noasaurus"/>. Troodontids were once included in
2271 Deinonychosauria because of their "sickle claws", but they are usually now
2272 recognized as relatives of <LINK content="ornithomimosaurs"/> (a.k.a.
2273 "ostrich mimics"). </P>
2275 <P> The attack strategy of a dromaeosaurid was possibly to leap at its
2276 prey, feet and arms extended. This posture would be balanced by the long,
2277 stiff tail. The dromaeosaurid would grab onto its prey with cruel,
2278 grasping hands, then tear out the unfortunate creature's throat or guts
2279 with the eviscerating foot-claws. </P>
2281 <P> The energy and quickness needed to carry out such a maneuver is one
2282 piece of evidence used in the debate over whether <LINK
2283 content="dinosaurs"/> were cold-blooded or warm-blooded. </P>
2285 <P header="Speculation on Behavior"> These dinosaurs may have hunted in packs, as shown by one find where
2286 three <NOMEN name="Deinonychus"/> skeletons were found near a skeleton of
2287 the herbivore <NOMEN name="Tenontosaurus"/>. But another dromaeosaurid
2288 find shows a solitary <NOMEN name="Velociraptor"/> locked in combat with a
2289 <NOMEN name="Protoceratops"/>. It may be that these creatures used
2290 whatever hunting strategy fitted the situation, as wolves (<NOMEN
2291 name="Canis lupus" nolink="1"/>) do today, or that behavior varied between
2292 species, as in gregarious lions (<NOMEN name="Panthera leo" nolink="1"/>)
2293 and solitary tigers (<NOMEN name="Panthera tigris" nolink="1"/>). </P>
2295 <P header="Feathered Friends"> Dromaeosaurids were probably very close to
2296 <LINK content="bird"/> ancestry, as shown by their bird-like hip arrangement
2297 (unusual for non-<LINK content="avian"/> <LINK content="saurischians"/>),
2298 extremely stiffened tails, and their similarity to the feathered, flying
2299 <NOMEN name="Archaeopteryx"/>. In fact, the most recently published
2300 deinonychosaur, <NOMEN name="Sinornithosaurus"/>, shows impressions
2301 of feathers or feather-like integument (not too much of a surprise,
2302 since feathered dinosaurs less closely related to birds had already been
2303 found). They may have even been secondarily flightless,
2304 like modern-day <LINK content="ratite"/> birds.</P>
2306 <P header="Movie Stars"> "'Raptors" were one of the major stars of the blockbuster movie
2307 <U>Jurassic Park</U>. Although this movie and its sequel, <U>Jurassic Park
2308 2: The Lost World</U> boasts the most accurate dinosaurs in the history of
2309 movies, there are a significant number of errors, especially with the
2310 "'raptors". The most obvious problem is that they were much too big. Real
2311 <NOMEN name="Velociraptor"/> were about the size of jackals. Even <NOMEN
2312 name="Velociraptor"/>'s big brother <NOMEN name="Deinonychus"/> wasn't as
2313 big as <U>Jurassic Park</U>'s "'raptors". </P>
2315 <P> The reason for this is probably as follows. Michael Crichton wanted to
2316 use a fierce, approximately man-sized predator. <NOMEN
2317 name="Deinonychus"/> was ideal. But he also wanted the name <NOMEN
2318 name="Velociraptor"/> for plot reasons. Luckily for him, there was one
2319 dinosaur researcher who believed the two dinosaurs were similar enough to
2320 be in the same genus, which by virtue of seniority would be called <NOMEN
2321 name="Velociraptor"/>. So, Crichton used <NOMEN name="Deinonychus"/> but
2322 called it <NOMEN name="Velociraptor"/>. (Since then, new studies of the
2323 skulls have shown them to be separate genera.) </P>
2325 <P> For the movie they decided to bump the size up. They also gave it a
2326 more <NOMEN name="Deinonychus"/>-like head, unlike <NOMEN
2327 name="Velociraptor"/>'s, which has a rather concave snout. </P>
2329 <P> Interestingly, while the movie was being made, a new dromaeosaurid was
2330 found which was even larger than the movie's "'raptor". The discovery of
2331 this new dinosaur (<NOMEN name="Utahraptor"/>) showed that there actually
2332 must have been a <NOMEN name="Deinonychus"/>-like creature about the same
2333 size as the ones in Jurassic Park, an intermediate in size between
2334 <NOMEN name="Utahraptor"/> and <NOMEN name="Deinonychus"/>. In fact, some
2335 undescribed forms may fit the bill. </P>
2337 <P> So the "'raptor" in <U>Jurassic Park</U> is probably a decent
2338 approximation of a real, undescribed dromaeosaurid (not a <NOMEN
2339 name="Velociraptor"/>, though), except for some further inaccuracies, like
2340 the flexible tail, the incorrect hands, and the lack of feathers. </P>
2344 <TAXON name="Dinosauria" nickname='"Fearfully Great Reptiles"'>
2345 <WORD key="1" content="terrible, fearfully, great, lizards, reptiles, hip, pelvis"/>
2346 <WORD essay="1" content="saurischian dinosaurs"/>
2348 <CLADE name="Dinosauria" in="Neornithes, Triceratops" silhouette="dinosauria">
2349 <AUTHOR name="Owen" year="1842"/>
2350 <AUTHOR type="sensu" name="Padian, May" year="1993"/>
2352 fearfully great lizards
2354 <CSYNONYM name="Ornithoscelida"/>
2355 <CSYNONYM name="Pachypoda"/>
2356 <CSYNONYM name="Pachypodes"/>
2359 <PLACE name="Mississippi"/>
2360 <REMAINS content="sacrum"/>
2362 <CGENUS incertae="1" name="Beelemodon"/>
2363 <CGENUS incertae="1" name="Luanpingosaurus"/>
2364 <CGENUS incertae="1" name="Teyuwasu"/>
2365 <CLINK name="Ornithischia"/>
2366 <CLADE name="Saurischia" in="Neornithes" out="Triceratops">
2367 <AUTHOR name="Seeley" year="1888"/>
2368 <AUTHOR type="sensu" name="Gauthier" year="1986"/>
2370 lizard<LOW>-like</LOW> ischia
2372 <CLADE name="Guaibasauridae">
2373 <CGENUS name="Guaibasaurus"/>
2375 <CLINK name="Sauropodomorpha"/>
2376 <CLINK name="Theropoda"/>
2380 <CLADOGRAM alternate="1">
2382 <CGENUS name="Eoraptor"/>
2384 <CLADE name="Herrerasauridae"/>
2385 <CLADE name="Dinosauria"/>
2389 <CLADOGRAM alternate="1">
2390 <CLADE name="Dinosauria">
2391 <CLADE name="Ornithischia"/>
2392 <CLADE name="Saurischia">
2393 <CGENUS name="Eoraptor"/>
2395 <CLADE name="Herrerasauridae"/>
2396 <CLADE name="Eusaurischia" status="informal">
2400 <CLADE name="Sauropodomorpha"/>
2401 <CLADE name="Theropoda"/>
2407 <CLADOGRAM alternate="1">
2408 <CLADE name="Dinosauria">
2409 <CLADE name="Theropoda"/>
2410 <CLADE name="Phytodinosauria">
2411 <CSYNONYM name="Ornithischia"/>
2413 plant<LOW>-eating</LOW> dinosaurs
2415 <CLADE name="Sauropodomorpha" comment="altered definition"/>
2416 <CLADE name="Ornithischia" comment="altered definition"/>
2421 <P header="The Divisions"> There are three major types of dinosaur. <LINK content="Theropoda"/>
2422 includes all of the carnivorous dinosaurs, as well as their modern-day
2423 descendants, the <LINK content="birds"/>. <LINK
2424 content="Sauropodomorpha"/> consists of long-necked herbivorous dinosaurs,
2425 including <LINK content="sauropods"/>, the largest land
2426 animals of all time. The third group, <LINK content="Ornithischia"/>,
2427 contains many diverse forms of beaked, herbivorous dinosaurs. </P>
2429 <P header="Evolution and Relationships"> Although the major groups of
2430 dinosaurs are clearly recognized, there
2431 is some debate about their relationships to each other and to the
2432 ancestors of dinosaurs. About the only thing that can be confidently
2433 stated about early dinosaurian/<LINK content="ornithodiran"/> evolution is
2434 that the following evolutionary lineage occured:
2436 ancestral ornithodiran
2438 +--><NOMEN name="Lagerpeton"/>
2440 +--><NOMEN name="Marasuchus"/>
2442 +--><NOMEN name="Pseudolagosuchus"/>
2444 +--><NOMEN name="Eoraptor"/>
2446 +--><NOMEN name="Herrerasaurus"/>
2449 <LINK content="Neotheropoda"/>
2452 <P> <LINK content="Pterosaurs"/> are thought to have split off from this
2453 lineage probably before <NOMEN name="Lagerpeton"/> (some don't think
2454 pterosaurs are particularly closely related to dinosaurs at all).
2455 Ornithischians probably split off somewhere before <NOMEN name="Eoraptor"/>,
2456 but perhaps between <NOMEN name="Herrerasaurus"/> and
2457 Neotheropoda. Sauropodomorphs could have split off anywhere before
2458 Neotheropoda, but after Ornithischia, or possibly with it. </P>
2460 <P header="Definition"> The confusion about dinosaur ancestry leads to the question "What is a
2461 dinosaur?" The original definition of Dinosauria, as stated by Sir Richard
2462 Owen in 1842, was a group of large <LINK content="reptiles"/> (which he
2463 considered a type of <LINK content="lizard"/>) consisting of <NOMEN
2464 name="Megalosaurus"/>, <NOMEN name="Iguanodon"/>, and <NOMEN
2465 name="Hylaeosaurus"/>, the only non-<LINK content="neornithean"/> dinosaur
2466 genera described at that time (save for <NOMEN name="Cetiosaurus"/> and
2467 <NOMEN name="Streptospondylus"/>, which Owen thought to be aquatic, <LINK
2468 content="crocodile"/>-like creatures, and some mainland European forms
2469 like <NOMEN name="Plateosaurus"/> and <NOMEN name="Poekilopleuron"/>,
2470 which Owen had not examined). </P>
2472 <P> Dinosauria was traditionally divided into the orders Ornithischia
2473 ("bird hips" -- a misleading term) and Saurischia ("lizard hips"). For
2474 much of the history of paleontology, the status of Dinosauria as a real
2475 group has been considered dubious -- Ornithischia and Saurischia were
2476 separated from each other and sometimes were themselves split up. More
2477 recently, however, cladistic analysis has reaffirmed Dinosauria as a
2478 natural group. It is defined as the most recent common ancestor of <LINK
2479 content="modern birds"/> (which are now considered saurischians) and
2480 <NOMEN name="Triceratops"/> (an ornithischian), plus all of that
2481 ancestor's descendants. (As some have noted, it might have been more
2482 proper to use <NOMEN name="Megalosaurus"/> and <NOMEN name="Iguanodon"/>
2483 as anchors instead of birds and <NOMEN name="Triceratops"/>, but this
2484 phylogenetic definition has priority, and, by all cladistic studies,
2485 represents the same group anyway. Besides, the type specimens of <NOMEN
2486 name="Iguanodon"/> and <NOMEN name="Megalosaurus"/> are rather poor.) </P>
2488 <P> This definition has lead to some disagreement as to whether certain
2489 primitive ornithodirans are dinosaurs or not. Some include all of the
2490 genera shown in the above lineage in Dinosauria, whereas others don't even
2491 consider <LINK content="herrerasaurids"/> to be true dinosaurs. On these
2492 pages <NOMEN name="Eoraptor"/> is considered the most primitive known true
2493 dinosaur, and probably a primitive theropod, due to such characteristics
2494 as highly reduced manual digits IV and V (neotheropods have no digit V and
2495 either no digit IV or a reduced one). </P>
2497 <P header="An Alternate View"> <ILLO name="saurischian_pelvis" caption="saurischian pelvis" align="left"/>
2498 <ILLO name="ornithischian_pelvis" caption="ornithischian pelvis" align="right"/>
2499 The uncertainty revolving about the origins of the major dinosaur groups
2500 has also caused another debate. Traditionally, Sauropodomorpha has been
2501 grouped with Theropoda in Saurischia, sister group to the Ornithischia.
2502 This is due to the fact that both saurischian groups have a primitive
2503 lizard-like hip bone arrangement, with the pubis pointing forward (except
2504 for some advanced groups), while ornithischians have a derived,
2505 superficially bird-like arrangement where a process on the pubis points
2506 backwards. (In birds and some bird-like theropods, the pubis itself
2507 points backwards.) </P>
2509 <P> But a minority claim that early sauropodomorphs show more similarities
2510 to early ornithischians than to theropods. They classify Sauropodomorpha
2511 and Ornithischia in Phytodinosauria ("plant dinosaurs") as a sister taxon
2516 <TAXON name="Diplodocidae" nickname="Whip-Tails & Earth-Shakers">
2517 <WORD key="1" content="giant, huge, long, longest, biggest, whip, tail, whiptail, quake, seism"/>
2519 <CLADE name="Diplodocidae" silhouette="diplodocidae">
2522 <PLACE name="England"/>
2524 <CGENUS name="Dinheirosaurus" incertae="1"/>
2525 <CGENUS name="Dyslocosaurus" incertae="1"/>
2526 <CGENUS name="Dystrophaeus" incertae="1"/>
2527 <CLADE name="Apatosaurinae" silhouette="apatosaurinae">
2528 <CGENUS name="Apatosaurus"/>
2529 <CGENUS name="Eobrontosaurus"/>
2531 <CLADE name="Diplodocinae">
2533 <PLACE name="Georgian Republic"/>
2535 <CGENUS name="Barosaurus"/>
2536 <CGENUS name="Diplodocus"/>
2538 <CGENUS name="Dystylosaurus"/>
2539 <CGENUS name="Seismosaurus"/>
2540 <CGENUS name="Supersaurus"/>
2546 <P> Diplodocids included some of the hugest creatures to walk upon the
2547 Earth. <NOMEN name="Supersaurus"/> and <NOMEN name="Seismosaurus"/>
2548 probably weighed in at 45-60 metric tonnes. </P>
2550 <P header="Digital Dinos"> These animals have been the focus of several computer-assisted studies
2551 in biophysics. One study suggests that diplodocids could actually crack
2552 their tails like whips, causing loud sonic booms. Another study, focusing
2553 on the other end of the animals, suggests that they could not hold their
2554 heads very high, and thus may have fed on low-growing vegetation. This
2555 goes against previous thought that <LINK content="sauropods"/> evolved their
2556 long necks to reach into the trees. </P>
2558 <P header="Integument"> Recently a diplodocid was found with non-bony dermal spines along its
2559 back. Since non-bony structures are rarely preserved, it is not certain
2560 how widely throughout <LINK content="Sauropodomorpha"/> this feature
2565 <TAXON name="Diplodocimorpha" nickname="Sailback Sauropods & Kin">
2566 <WORD key="1" content="sail, sailback, finback"/>
2568 <CLADE name="Diplodocimorpha" in="Diplodocus" out="Saltasaurus" silhouette="diplodocimorpha">
2570 <NOMEN name="Diplodocus"/> forms
2573 <TIME value="Cenomanian" q="1"/>
2574 <PLACE name="Argentina"/>
2576 <CGENUS name="Hisanohamasaurus" incertae="1" q="1"/>
2577 <CGENUS name="Megacervixosaurus" incertae="1" q="1"/>
2578 <CGENUS name="Mongolosaurus" incertae="1" q="1"/>
2579 <CGENUS name="Amphicoelias"/>
2580 <CLADE name="Rebbachisauridae" silhouette="rebbachisauridae">
2582 <PLACE name="S. America"/>
2584 <REMAINS content="dentary"/>
2586 <CGENUS name="Histriasaurus" q="1" incertae="1"/>
2587 <CGENUS name="Nigersaurus"/>
2588 <CGENUS name="Rayososaurus"/>
2589 <CLADE name="Rebbachisaurinae">
2590 <CGENUS name="Limaysaurus"/>
2591 <CGENUS name="Rebbachisaurus"/>
2594 <CLADE name="Diplodocoidea" in="Diplodocus, Dicraeosaurus">
2595 <CLADE name="Dicraeosauridae">
2596 <UNNAMED cf="Dicraeosaurus" q="1">
2597 <TIME value="Albian"/>
2598 <TIME value="Cenomanian" section="early"/>
2599 <PLACE name="Africa"/>
2601 <CGENUS name="Amargasaurus" silhouette="amargasaurus"/>
2602 <CGENUS name="Dicraeosaurus"/>
2604 <CLINK name="Diplodocidae"/>
2608 <CLADOGRAM alternate="1">
2609 <CLADE name="Diplodocimorpha">
2611 <CLADE name="Diplodocoidea"/>
2612 <CLADE name="Rebbachisauridae"/>
2615 <CGENUS name="Antarctosaurus" q="1"/>
2616 <CLADE name="Nemegtosauridae">
2617 <CGENUS name="Nemegtosaurus"/>
2618 <CGENUS name="Quaesitosaurus"/>
2624 <P> Members of this group had long, whip-like tails
2625 (possibly used for defense), peg-like teeth, and high vertebral spines.
2626 The extremely long spines of some diplodocimorphs, such as
2627 <NOMEN name="Amargasaurus"/> and <NOMEN name="Rebbachisaurus"/>,
2628 may have formed large dorsal sails, like those of the
2629 <LINK content="theropod"/> <NOMEN name="Spinosaurus"/> and the
2630 <LINK content="ornithopod"/> <NOMEN name="Ouranosaurus"/>. </P>
2632 <P> Some of these animals, like the dicraeosaurids, made it into the
2633 Cretaceous, but not to the end of the Mesozoic Era. </P>
2635 <P header="The Elusive Giant"> There is a possible diplodocimorph named <NOMEN name="Amphicoelias fragillimus"/>, known
2636 from a drawing of a crumbling neural arch. Based on comparison to
2637 other diplodocimorphs, it would have been about 50m long and weighed about
2638 120-150 tonnes, making it by far the largest land creature of all time!
2639 Unfortunately, the actual specimen has been lost, presumably disintegrated,
2640 for a long time (if it ever, indeed, existed). </P>
2644 <TAXON name="Enantiornithes" nickname='"Opposite Birds"'>
2645 <WORD key="1" content="bird, toothed, toothless, teeth, opposite, avian"/>
2647 <CLADE name="Enantiornithes" in="Enantiornis" out="Neornithes" silhouette="pygostylia">
2651 <UNNAMED comment="juvenile">
2652 <PLACE name="Spain"/>
2654 <CGENUS incertae="1" name="Eoalulavis"/>
2655 <CGENUS incertae="1" name="Gurilynia"/>
2656 <CGENUS name="Iberomesornis" q="1"/>
2657 <CGENUS name="Lingyuanornis" incertae="1"/>
2658 <CGENUS name="Vorona" q="1" silhouette="paraves"/>
2659 <CLADE name="Alexornithiformes" incertae="1">
2660 <CGENUS name="Alexornis"/>
2661 <CGENUS name="Kizylkumavis"/>
2662 <CGENUS name="Lenesornis"/>
2663 <CGENUS name="Sazavis"/>
2665 <CLADE name="Eoenantiornithiformes" q="1">
2666 <MEANING><NOMEN name="Eoenantiornis"/> forms</MEANING>
2667 <CGENUS name="Eoenantiornis"/>
2670 <CLADE name="Sinornithiformes">
2671 <CGENUS name="Sinornis"/>
2674 <CLADE name="Cathayornithiformes">
2676 <NOMEN name="Cathayornis"/> forms
2678 <CLADE name="Cuspirostrisornithidae" q="1">
2679 <CGENUS name="Cuspirostrisornis"/>
2680 <CGENUS name="Largirostrisornis"/>
2682 <CLADE name="Cathayornithidae">
2683 <CGENUS name="Boluochia"/>
2684 <CGENUS name="Cathayornis"/>
2685 <CGENUS name="Longchengornis"/>
2689 <CLADE name="Gobipterygidae">
2690 <CGENUS name="Gobipteryx"/>
2691 <CGENUS name="Horezmavis"/>
2693 <CLADE name="Enantiornithiformes">
2695 <NOMEN name="Enantiornis"/> forms
2697 <CLADE name="Zhyraornithidae" q="1">
2698 <CGENUS name="Zhyraornis">
2700 <CLADE name="Enantiornithidae">
2701 <CGENUS name="Enantiornis"/>
2702 <CGENUS name="Nanantius"/>
2704 <CLADE name="Avisauridae">
2705 <CGENUS name="Lectavis"/>
2707 <CGENUS name="Yungavolucris"/>
2709 <CGENUS name="Concornis" q="1"/>
2711 <CGENUS name="Neuquenornis"/>
2713 <CGENUS name="Avisaurus"/>
2714 <CGENUS name="Soroavisaurus"/>
2727 <P header="Characteristics"> Enantiornitheans were a large group of <LINK content="birds"/> which
2728 evolved alongside modern-style birds, or <LINK content="neornitheans"/>,
2729 during the <LINK content="Cretaceous Period"/>. Their name ("opposite birds")
2731 to the articulation of the scapula with the coracoid, opposite to that of
2732 modern birds. Like neornitheans, advanced enantiornitheans were toothless.
2733 These two lineages, along with <LINK content="confuciusornithids"/>,
2734 <LINK content="oviraptorosaurs"/>, and <LINK content="ornithomimosaurs"/>,
2735 represent the five known lineages of toothless
2736 <LINK content="coelurosaur"/>. </P>
2738 <P header="Rise and Fall"> Enantiornitheans achieved a fair degree of
2739 diversity, beginning as
2740 small, perching fliers, with some developing into shorebirds. They
2741 ranged from sparrow- to vulture-size. </P>
2743 <P> Although apparently more plentiful than their neornithean cousins
2744 during the Cretaceous, enantiornitheans, like all non-neornithean
2745 dinosaurs, became extinct at the end of the Cretaceous. Why neornitheans
2746 survived while they did not remains a mystery. </P>
2750 <TAXON name="Hadrosaurinae" nickname="Small- & Non-Crested Duckbills" silhouette="edmontosaurini">
2751 <WORD key="1" content="hadrosaur, ducknill, duck, bill, non, crest, crested"/>
2752 <WORD essay="1" content="gryposaurin hadrosaurine"/>
2754 <CLADE name="Hadrosaurinae" in="Hadrosaurus" out="Lambeosaurus" silhouette="hadrosaurinae">
2755 <CSYNONYM name="Saurolophinae"/>
2756 <CGENUS name="Hadrosaurus" incertae="1"/>
2757 <CGENUS name="Microhadrosaurus" incertae="1"/>
2758 <CGENUS name="Thespesius" incertae="1" q="1"/>
2759 <CLADE name="Maiasaurini" silhouette="maiasaurini">
2760 <CGENUS name="Brachylophosaurus"/>
2761 <CGENUS name="Maiasaura"/>
2764 <CLADE name="Gryposaurini">
2765 <CSYNONYM name="Hadrosaurini" q="1"/>
2766 <CGENUS name="Aralosaurus" q="1"/>
2767 <CGENUS name="Gryposaurus"/>
2770 <CLADE name="Edmontosaurini" silhouette="edmontosaurini">
2771 <CGENUS name="Anatotitan"/>
2772 <CGENUS name="Edmontosaurus"/>
2773 <CGENUS name="Shantungosaurus"/>
2774 <CGENUS name="Tanius" q="1"/>
2776 <CLADE name="Saurolophini">
2777 <CGENUS name="Anasazisaurus"/>
2778 <CGENUS name="Kritosaurus"/>
2779 <CGENUS name="Naashoibitosaurus"/>
2780 <CGENUS name="Prosaurolophus" silhouette="prosaurolophus-saurolophus"/>
2781 <CGENUS name="Saurolophus" silhouette="prosaurolophus-saurolophus"/>
2788 <P> These "duck-billed" <LINK content="dinosaurs"/> were mostly non-crested,
2789 although some, like <NOMEN name="Maiasaura"/> and <NOMEN name="Saurolophus"/>,
2790 had small, spiky crests. Hadrosaurines include the largest
2791 <LINK content="ornithopods"/> of all time, such as the enormous
2792 <NOMEN name="Shantungosaurus"/>, which was on par with small- to medium-sized
2793 <LINK content="sauropods"/>. </P>
2795 <P> Before the discovery of <NOMEN name="Hadrosaurus"/>, dinosaurs were
2796 generally thought to be
2797 all quadrupedal. <NOMEN name="Hadrosaurus"/>' long hindlimbs and relatively
2798 short forelimbs indicated otherwise. It was originally reconstructed
2799 standing upright, like a human. Now it is thought that all hadrosaurs,
2800 indeed, all <LINK content="iguanodontians"/> were facultatively
2801 quadrupedal, able to move on all fours or on two legs, with the back
2802 horizontal in all positions. </P>
2804 <P> The old genus <NOMEN name="Anatosaurus"/> has recently been sunk into
2805 <NOMEN name="Edmontosaurus"/>, except for one separate species, for which
2806 the generic name <NOMEN name="Anatotitan"/> was coined. </P>
2810 <TAXON name="Hadrosauroidea" nickname="Duck-Billed Dinosaurs">
2811 <WORD key="1" content="duckbill, duck, bill, duckbilled, sail, finback, sailback, fin"/>
2812 <WORD key="1" essay="1" content="hadrosaur, hadrosaurs"/>
2813 <WORD essay="1" content="duck-bill, duck-billed dinosaurs"/>
2815 <CLADE name="Hadrosauroidea" in="Hadrosaurus" out="Iguanodon" silhouette="hadrosauroidea">
2816 <UNNAMED comment="sail-backed" q="1" silhouette="ouranosaurus">
2817 <TIME value="Barremian"/>
2818 <PLACE name="Utah"/>
2820 <CGENUS name="Altirhinus"/>
2821 <CGENUS name="Ouranosaurus" silhouette="ouranosaurus"/>
2823 <CGENUS name="Nanyangosaurus"/>
2824 <CLADE name="Hadrosauridae">
2826 <TIME value="Maastrichtian"/>
2827 <PLACE name="Belgium"/>
2830 <TIME section="late" value="LK"/>
2831 <PLACE name="Italy"/>
2834 <TIME value="Albian"/>
2835 <PLACE name="Utah"/>
2838 <REMAINS content="femur, ischium"/>
2839 <TIME value="Coniacian"/>
2840 <PLACE name="Japan"/>
2843 <REMAINS content="phalanx, caudal centrum"/>
2845 <PLACE name="Mississippi"/>
2848 <REMAINS content="tooth"/>
2849 <TIME value="Coniacian"/>
2850 <TIME value="Santonian"/>
2851 <PLACE name="Japan"/>
2854 <TIME value="Maastrichtian"/>
2855 <PLACE name="Antarctica"/>
2858 <TIME value="Maastrichtian" section="late"/>
2859 <PLACE name="France"/>
2861 <CGENUS incertae="1" name="Hironosaurus" q="1"/>
2862 <CGENUS incertae="1" name="Hypsibema"/>
2863 <CGENUS incertae="1" name="Lophorhothon"/>
2864 <CGENUS incertae="1" name="Mandschurosaurus"/>
2865 <CGENUS incertae="1" name="Orthomerus"/>
2866 <CGENUS incertae="1" name="Sanpasaurus"/>
2867 <CGENUS incertae="1" name="Secernosaurus"/>
2868 <CGENUS name="Protohadros"/>
2870 <CGENUS name="Claosaurus"/>
2871 <CGENUS name="Gilmoreosaurus"/>
2872 <CGENUS name="Telmatosaurus"/>
2873 <CLADE name="Euhadrosauria" in="Hadrosaurus, Lambeosaurus">
2874 <CSYNONYM name="Hadrosauridae" sensu="Sereno"/>
2875 <CLINK name="Lambeosaurinae"/>
2876 <CLINK name="Hadrosaurinae"/>
2883 <CLADOGRAM alternate="1">
2884 <REFER page="Iguanodontia"/>
2887 <P> These are commonly known as the "duck-billed" dinosaurs, since their
2888 beaks bore a superficial resemblance to those of ducks. They were the last,
2889 largest, and most numerous of the <LINK content="ornithopods"/>. </P>
2891 <P> More "primitive" hadrosauroids like <NOMEN name="Ouranosaurus"/>
2892 had small thumb-spikes,
2893 like the larger thumb-spikes of other <LINK content="iguanodontians"/>.
2894 This digit was lost entirely in hadrosaurids. <NOMEN name="Ouranosaurus"/>
2895 and an unnamed hadrosauroid possessed large sails on their backs, like those
2896 of <NOMEN name="Spinosaurus"/> and
2897 <NOMEN name="Rebbachisaurus"/>. </P>
2899 <P> Hadrosaurids are divided into two subfamilies, the generally non-crested
2900 hadrosaurines and the lambeosaurines, which developed large hollow crests
2901 on their heads. At least one scientist considers them to be two separate families,
2902 with <NOMEN name="Iguanodon"/> closer to the hadrosaurids and
2903 <NOMEN name="Ouranosaurus"/> closer to the lambeosaurids. </P>
2905 <P header="In Water or On Land?"> It was once thought that the duck-bills, like their namesakes, were
2906 aquatic. This notion seemed to be supported when a fossilized "mummy" of a
2907 hadrosaurid was discovered, showing what appeared to be webbed fingers on
2908 the hands. The hollow crests of the lambeosaurines were supposed to be for
2909 air storage, since they connected to the nasal passages. </P>
2911 <P> This theory is largely out of favor now. The "webbed" fingers, upon
2912 closer scrutiny, more closely resemble desiccated hoof pads. The crests
2913 could not have functioned as air storage, since they were rigid and
2914 inflexible. Air sucked out of them would have created a vacuum. And the
2915 rugged teeth of the hadrosaurids strongly indicate that they ate rough, woody
2916 plant material, not soft seaweed. The teeth in the jaw were aligned in great
2917 "batteries", so that if one wore out there was another one behind it to
2918 replace it. Some hadrosaurid jaws contained as much as 2,000 teeth! </P>
2920 <P> It seems that duck-bills led a largely terrestrial life. They would walk
2921 primarily on all fours, as shown by the hoof-like nails and supporting pads
2922 on the hands, but were easily capable of switching to bipedal locomotion. </P>
2926 <TAXON name="Hesperornithiformes" nickname="Toothed Marine Birds">
2927 <WORD key="1" content="bird, toothed, teeth, avian, aquatic, loon, marine, sea, seagoing, sea-going, oceanic, water, swimming, diving"/>
2929 <CLADE name="Hesperornithiformes" silhouette="hesperornithiformes">
2931 <NOMEN name="Hesperornis"/> forms
2933 <CGENUS name="Enaliornis"/>
2935 <CGENUS name="Pasquiaornis"/>
2937 <CGENUS name="Baptornis"/>
2938 <CGENUS name="Judinornis"/>
2939 <CLADE name="Hesperornithidae">
2940 <CGENUS incertae="1" name="Coniornis"/>
2941 <CGENUS name="Asiahesperornis"/>
2942 <CGENUS name="Parascaniornis"/>
2943 <CLADE name="Hesperornithinae">
2944 <CGENUS name="Hesperornis"/>
2945 <CGENUS name="Parahesperornis"/>
2953 <P> These are the only known marine <LINK content="dinosaurs"/> of the
2954 <LINK content="Mesozoic Era"/>! Hesperornithiforms had adapted to life in
2955 the oceans of Laurasia, and are best known from the
2956 North American interior, which was covered by a large sea during much of the
2957 <LINK content="Cretaceous"/>. </P>
2959 <P> Unlike the major modern-day group of marine birds (penguins),
2960 which have flipper-like wings, hesperornithiforms propelled
2961 themselves with large, (presumably) webbed feet, like loons
2962 and grebes. Their wings had atrophied to tiny, useless things, and their
2963 feet were set so far back that walking must have been extremely awkward.
2964 Thus, they probably spent very nearly all of their time in the water. </P>
2968 <TAXON name="Heterodontosauridae" nickname="Little Tuskers">
2969 <WORD key="1" content="heterodontosaur, fang, caniniform, tusk, tusker, tooth, teeth"/>
2970 <WORD essay="1" content="lithe tuskers"/>
2972 <CLADE name="Heterodontosauridae" silhouette="cerapoda">
2973 <AUTHOR name="Romer" year="1966"/>
2974 <UNNAMED comment="small">
2976 <PLACE name="U.S.A."/>
2978 <CGENUS name="Dianchungosaurus" incertae="1" q="1"/>
2979 <CGENUS name="Geranosaurus" incertae="1"/>
2980 <CGENUS name="Lanasaurus"/>
2981 <CLADE name="Heterodontosaurinae">
2982 <CGENUS name="Abrictosaurus"/>
2983 <CLADE name="Heterodontosaurini">
2984 <CGENUS name="Heterodontosaurus"/>
2985 <CGENUS name="Lycorhinus"/>
2991 <P> Heterodontosaurids were a group of small, primitive
2992 <LINK content="ornithischians"/>
2993 from the <LINK content="Early Jurassic"/>. They
2994 were all fairly similar to each other. Some species, such as
2995 <NOMEN name="Heterodontosaurus tucki"/>, bore small tusks while others, like
2996 <NOMEN name="Abrictosaurus consors"/>, were tuskless. It has been suggested
2997 that perhaps only one gender bore tusks, and what are currently considered
2999 species may only be separate genders of the same species. </P>
3001 <P> Heterodontosaurids were traditionally considered primitive
3002 <LINK content="ornithopods"/>, although they bear a number of similarities to
3003 <LINK content="marginocephalians"/> as well. </P>
3007 <TAXON name="Ichthyopterygia" nickname="Reptilian Dolphins" simple="1">
3008 <WORD key="1" content="fish, lizard, fish-lizard, marine, reptile, aquatic, sea, oceanic"/>
3009 <INCLUDED content="Stenopterygius"/>
3011 <CLADE name="Ichthyopterygia" in="Ichthyosaurus" out="Plesiosaurus, Lepidosauria, Archosauria" silhouette="ichthyopterygia">
3012 <AUTHOR name="Owen" year="1840"/>
3013 <MEANING>fish flippers</MEANING>
3014 <CLADE name="Hupehsuchidae" q="1"/>
3015 <CLADE in="Ichthyosaurus, Parvinatator, Utatsusaurus">
3016 <CSYNONYM name="Ichthyopterygia" sensu="Motani" year="1999"/>
3017 <CGENUS name="Isfjordosaurus" incertae="1"/>
3018 <CGENUS name="Thaisaurus" incertae="1"/>
3019 <CGENUS name="Parvinatator"/>
3020 <CGENUS name="Utatsusaurus"/>
3021 <CLADE name="Eoichthyosauria" in="Grippia, Ichthyosaurus">
3022 <AUTHOR name="Motani" year="1999"/>
3023 <MEANING>dawn ichthyosaurs</MEANING>
3024 <CLADE name="Grippidia">
3025 <AUTHOR name="Wiman" year="1929"/>
3026 <CGENUS name="Chaohusaurus"/>
3027 <CGENUS name="Grippia"/>
3029 <CLADE name="Ichthyosauria" in="Ichthyosaurus" out="Grippia">
3030 <MEANING>fish lizards/<NOMEN name="Ichthyosaurus" nolink="1">' <LOW>taxon</LOW></MEANING>
3031 <AUTHOR name="Blainville" year="1835"/>
3032 <AUTHOR type="sensu" name="Motani" year="1999"/>
3033 <CGENUS name="Mikadocephalus" incertae="1"/>
3034 <CGENUS name='"Shastasaurus" neubigi' incertae="1"/>
3035 <CGENUS name="Wimanius" incertae="1"/>
3036 <CGENUS name="Cymbospondylus"/>
3038 <CLADE name="Mixosauridae">
3039 <AUTHOR name="Baur" year="1887"/>
3041 <CLADE name="Merriamosauria" in="Shastasaurus, Ichthyosaurus">
3042 <AUTHOR name="Motani" year="1999"/>
3043 <CLADE name="Shastasauria" in="Shastasaurus" out="Ichthyosaurus">
3044 <MEANING><NOMEN name="Shastasaurus" nolink="1">' <LOW>taxon</LOW></MEANING>
3045 <CGENUS name="Pessopteryx" incertae="1"/>
3046 <CLADE name="Shastasauridae" in="Besanosaurus, Shastasaurus">
3047 <AUTHOR name="Merriam" year="1908"/>
3048 <AUTHOR type="sensu" name="Motani" year="1999"/>
3051 <CLADE name="Euichthyosauria" in="Ichthyosaurus" out="Shastasaurus">
3052 <MEANING>true ichthyosaurs</MEANING>
3053 <AUTHOR name="Motani" year="1999"/>
3054 <CGENUS name="Toretocnemus"/>
3056 <CGENUS name="Californosaurus"/>
3057 <CLADE name="Parvipelvia" in="Macgowania, Ichthyosaurus">
3058 <MEANING>small pelves <LOW>(hips)</LOW></MEANING>
3059 <AUTHOR name="Motani" year="1999"/>
3060 <CGENUS name="Macgowania"/>
3062 <CGENUS name="Hudsonelpidia"/>
3064 <CGENUS name="Suevoleviathan"/>
3066 <CGENUS name="Temnodontosaurus"/>
3067 <CLADE name="Eurhinosauria">
3068 <AUTHOR name="Motani" year="1999"/>
3069 <CGENUS name="Leptonectes"/>
3070 <CGENUS name="Excalibosaurus"/>
3071 <CGENUS name="Eurhinosaurus"/>
3073 <CLADE name="Thunnosauria" in="Stenopterygius, Ichthyosaurus">
3074 <AUTHOR name="Motani" year="1999"/>
3075 <CGENUS name="Chacaicosaurus" incertae="1"/>
3076 <CGENUS name="Stenopterygius"/>
3078 <CGENUS name="Ichthyosaurus"/>
3079 <CLADE name="Opthalmosauridae">
3080 <AUTHOR name="Appleby" year="1956"/>
3098 <P> Despite their name, ichthyosaurs were neither <LINK content="fish"/> nor
3099 <LINK content="lizards"/>, but
3100 a <LINK content="sauropsid"/> group of uncertain origin that evolved into
3101 completely marine forms. Like sharks, they had dorsal fins and a tail
3102 fin that swept side-to-side. </P>
3104 <P> Ichthyosaurs arose during the <LINK content="Triassic"/>, but did not
3105 make it to the end of the <LINK content="Mesozoic Era"/>. They were gone
3106 before the K/T Extinction, which killed off other large marine
3107 <LINK content="reptiles"/> and the non-<LINK content="neornithean"/>
3108 <LINK content="dinosaurs"/>.
3111 <P> Unlike all other advanced <LINK content="tetrapods"/>, ichthyosaurs
3112 had more than five digits. It was once thought that they might be related
3113 to very early tetrapods like <NOMEN nolink="1" name="Ichthyostega"/>, which had
3114 as many as eight digits, but it seems more likely that they developed the
3115 extra digits from an ancestor with five digits, although this is the only
3116 known case of this happening in all of Tetrapoda. (Usually digits are
3121 <TAXON name="Iguanodontia" nickname="Spike-Thumbs - The Road to Duck-Bills" silhouette="iguanodontia-robust">
3122 <WORD key="1" content="iguanodont, spike, thumb, first"/>
3124 <CLADE name="Iguanodontia" in="Iguanodon" out="Hypsilophodon" silhouette="ornithopoda">
3126 <NOMEN name="Iguanodon"/>'s <LOW>taxon</LOW>
3129 <TIME value="Campanian"/>
3130 <TIME value="Maastrichtian"/>
3131 <PLACE name="New Zealand"/>
3134 <REMAINS content="tooth"/>
3135 <TIME section="late" value="Hauterivian"/>
3136 <TIME value="Barremian"/>
3137 <PLACE name="Japan"/>
3139 <UNNAMED comment="small">
3140 <TIME section="earliest" value="Cenomanian"/>
3141 <PLACE name="Utah"/>
3143 <CGENUS name="Caudocoelus" q="1"/>
3144 <CGENUS name="Magulodon" q="1"/>
3145 <CGENUS name="Mandschurosaurus laosensis" q="1"/>
3146 <CGENUS name="Muttaburrasaurus" q="1" silhouette="iguanodontia-robust"/>
3148 <CGENUS name="Tenontosaurus"/>
3149 <CLADE silhouette="iguanodontia-robust">
3150 <CGENUS name="Rhabdodon"/>
3151 <UNNAMED><PLACE name="Romania"/><TIME value="Maastrichtian"/></UNNAMED>
3152 <UNNAMED><PLACE name="Romania"/><TIME value="Maastrichtian"/></UNNAMED>
3155 <CLADE name="Euiguanodontia" in="Iguanodon, Gasparinisaura">
3159 <CGENUS name="Loncosaurus" incertae="1" q="1"/>
3160 <CGENUS name="Gasparinisaura"/>
3161 <CLADE name="Dryomorpha" in="Dryosaurus, Iguanodon">
3163 <NOMEN name="Dryosaurus"/> forms
3165 <CGENUS name="Anabisetia" q="1"/>
3166 <CLADE name="Dryosauridae">
3168 <PLACE name="Antarctica"/>
3170 <UNNAMED comment="tiny" indet="1">
3171 <PLACE name="Argentina"/>
3172 <TIME value="Turonian"/>
3174 <CGENUS name="Dryosaurus"/>
3175 <CGENUS name="Kangnasaurus" q="1"/>
3176 <CGENUS name="Valdosaurus"/>
3178 <CLADE name="Ankylopollexia" in="Parasaurolophus, Camptosaurus" silhouette="iguanodontia-robust">
3179 <UNNAMED comment="small">
3181 <PLACE name="S. Africa"/>
3183 <CGENUS incertae="1" name="Bihariosaurus"/>
3184 <CGENUS incertae="1" name="Pararhabdodon"/>
3185 <CGENUS name="Camptosaurus"/>
3186 <CLADE name="Styracosterna" in="Parasaurolophus" out="Camptosaurus">
3191 <TIME value="Albian"/>
3192 <TIME value="Cenomanian" section="early"/>
3193 <PLACE name="Africa"/>
3196 <TIME value="Campanian"/>
3197 <PLACE name="Antarctica"/>
3199 <CGENUS name="Fukuisaurus" incertae="1"/>
3200 <CGENUS name="Lurdusaurus" incertae="1" q="1"/>
3201 <CGENUS name="Probactrosaurus" incertae="1"/>
3202 <CLADE name="Iguanodontoidea" in="Iguanodon, Hadrosaurus">
3203 <CSYNONYM name="Hadrosauriformes"/>
3204 <CGENUS name="Camptosaurus sp." incertae="1"/>
3205 <CGENUS name="Craspedodon" incertae="1"/>
3206 <CGENUS name="Iguanodon"/>
3207 <CLINK name="Hadrosauroidea"/>
3215 <CLADOGRAM alternate="1">
3216 <CLADE name="Dryomorpha">
3217 <CLADE name="Iguanodontoidea"/>
3218 <CLADE name="Camptosauridae">
3219 <CLADE name="Dryosaurinae"/>
3220 <CLADE name="Camptosaurinae"/>
3224 <CLADOGRAM alternate="1">
3225 <CLADE name="Iguanodontoidea">
3227 <CGENUS name="Iguanodon"/>
3228 <CLADE name="Hadrosauridae">
3229 <AUTHOR type="sensu" name="Horner"/>
3233 <CGENUS name="Ouranosaurus"/>
3234 <CLADE name="Lambeosauridae"/>
3239 <P> The major characteristic of these medium- to large-sized herbivores is
3240 a spiky thumb, possibly used for defense against predators. When
3241 <NOMEN name="Iguanodon"/>, the first non-<LINK content="neornithean"/>
3242 <LINK content="dinosaur"/> to be scientifically described, was first put
3243 together, its thumb-spike was
3244 incorrectly placed on the nose, giving it the look of a reptilian
3247 <P header="Evolution"> The animals listed here cover the transition from early,
3248 <LINK content="hypsilophodont"/>-like iguanodontians to the medium-sized
3249 <NOMEN name="Camptosaurus"/> to the archetypal <NOMEN name="Iguanodon"/> to the
3250 <LINK content="duck-billed dinosaurs"/>, the end result of
3251 <LINK content="ornithopod"/> evolution. The evolution of the iguanodontian
3252 thumb can be seen along this line as well: small in
3253 <NOMEN name="Camptosaurus"/>, at its maximum
3254 in <NOMEN name="Iguanodon"/>, then tiny or absent in
3255 <LINK content="hadrosauroids"/>. </P>
3259 <TAXON name="Lambeosaurinae" nickname="Crested Duck-Bills" silhouette="lambeosaurus">
3260 <WORD key="1" content="duckbill, duck, bill, duck-bill, crest, crested, trumpet, sound, noise, vocalization, helmet, hatchet"/>
3261 <WORD essay="1" key="1" content="lambeosaur"/>
3262 <WORD essay="1" content="helmeted duck-bills"/>
3264 <CLADE name="Lambeosaurinae" in="Lambeosaurus" out="Hadrosaurus" silhouette="hadrosauroidea">
3265 <CSYNONYM name="Hypacrosaurinae"/>
3267 <TIME section="early" value="Maastrichtian"/>
3268 <PLACE name="Argentina"/>
3270 <CGENUS incertae="1" name="Arstanosaurus" q="1"/>
3271 <CGENUS name="Gadolosaurus" incertae="1" q="1"/>
3272 <CGENUS name="Pteropelyx" incertae="1"/>
3273 <CGENUS name="Trachodon" incertae="1"/>
3274 <CGENUS name="Eolambia"/>
3276 <CGENUS name="Bactrosaurus" q="1"/>
3278 <CLADE name="Parasaurolophini">
3279 <CGENUS name="Tsintaosaurus" q="1" silhouette="tsintaosaurus"/>
3280 <CLADE silhouette="parasaurolophus">
3281 <CGENUS name="Charonosaurus"/>
3282 <CGENUS name="Parasaurolophus"/>
3285 <CLADE name="Lambeosaurini">
3286 <CSYNONYM name="Hypacrosaurini"/>
3287 <CGENUS name="Nipponosaurus" incertae="1"/>
3288 <CGENUS name="Amurosaurus" q="1" silhouette="corythosaurus-hypacrosaurus"/>
3289 <CGENUS name="Jaxartosaurus"/>
3291 <CGENUS name="Lambeosaurus" silhouette="lambeosaurus"/>
3292 <CLADE silhouette="corythosaurus-hypacrosaurus">
3293 <CGENUS name="Barsboldia"/>
3294 <CGENUS name="Corythosaurus"/>
3295 <CGENUS name="Hypacrosaurus"/>
3304 <P header="Crests"> These "duck-billed" <LINK content="dinosaurs"/> bore large, hollow
3305 crests on their heads. The crests of <NOMEN name="Corythosaurus"/> and
3306 <NOMEN name="Hypacrosaurus"/> were semicircular.
3307 <NOMEN name="Lambeosaurus"/> crests were similar, but with a spike jutting
3308 out at the back of the crest. <NOMEN name="Parasaurolophus"/> had a very
3309 long crest pointing backwards from the head.
3310 <NOMEN name="Tsintaosaurus"/> was the "duck-billed unicorn", with a narrow
3311 spike pointing forward from above its eyes. </P>
3313 <P> The lambeosaurine crests may have been used as sexual displays. For many
3314 lambeosaurine genera, there are two forms known, one with a smaller
3315 crest, one with a larger crest. These were originally classified as different
3316 species, although in some cases they may just be different genders. </P>
3318 <P> In addition to visual display, the tubular crests, which connected to the
3319 nasal passages, may also have been used as giant trumpets, allowing the
3320 lambeosaurines to let out great, deep, resonant bellows across the
3321 prehistoric landscape. Another idea is that the crests enhanced their sense
3322 of smell, allowing them to detect giant predators. </P>
3326 <TAXON name="Lepidosauromorpha" nickname="Lizards, Mosasaurs, Snakes, Tuataras, & Kin" simple="1">
3327 <WORD key="1" content="snakes, tuataras, squamates"/>
3328 <WORD key="1" essay="1" content="lizards, mosasaurs"/>
3329 <WORD essay="1" content="lizard, mosasaur, snake"/>
3330 <INCLUDED content="Mosasaurus, Rikisaurus, Tylosaurus"/>
3332 <CLADE name="Lepidosauromorpha" in="Lepidosauria" out="Archosauria" silhouette="lepidosauromorpha">
3336 <CLADE extinct="1" name="Acerodontosauridae"/>
3338 <CLADE extinct="1" name="Younginiformes" q="1">
3339 <CSYNONYM name="Eosuchia"/>
3340 <CLADE extinct="1" name="Galesphyridae"/>
3341 <CLADE extinct="1" name="Tangasauridae"/>
3342 <CLADE extinct="1" name="Younginidae"/>
3345 <CLADE extinct="1" name="Paliguanidae"/>
3347 <CLADE extinct="1" name="Eolacertilia">
3348 <CLADE extinct="1" name="Fulengidae"/>
3349 <CLADE extinct="1" name="Kuehnosauridae"/>
3351 <CLADE name="Lepidosauria" crown="1">
3355 <CLADE name="Rhynchocephalia" in="Sphenodon" out="Squamata">
3359 <CSYNONYM name="Sphenodontida"/>
3360 <CGENUS extinct="1" name="Gephyrosaurus"/>
3362 <CGENUS extinct="1" name="Diphydodontosaurus"/>
3364 <CGENUS extinct="1" name="Planocephalosaurus"/>
3366 <CLADE extinct="1" name="Pleurosauridae"/>
3367 <CLADE name="Sphenodontidae" content="tuataras"/>
3373 <CGENUS extinct="1" name="Huehuecuetzpalli"/>
3374 <CGENUS extinct="1" name="Scandensia"/>
3375 <CLADE name="Squamata" crown="1">
3376 <CLADE name="Iguania">
3377 <CLADE extinct="1" name="Arretosauridae"/>
3378 <CLADE extinct="1" name="Euposauridae"/>
3379 <CLADE name="Iguanidae" content="iguanas, anoles, collared & horned lizards, etc."/>
3381 <CLADE name="Agamidae" content="agamas"/>
3382 <CLADE name="Chameleontidae" content="chameleons"/>
3385 <CLADE name="Scleroglossa">
3387 <CLADE name="Didamidae" q="1"/>
3388 <CLADE name="Amphisbaenia" content="worm lizards">
3389 <CLADE name="Amphisbaenidae"/>
3390 <CLADE name="Bipedidae"/>
3391 <CLADE extinct="1" name="Hyporhinidae"/>
3392 <CLADE extinct="1" name="Oligodontosauridae"/>
3393 <CLADE name="Rhineuridae"/>
3394 <CLADE name="Trogonophididae"/>
3397 <CLADE name="Gekkota">
3398 <CLADE extinct="1" name="Ardeosauridae" q="1"/>
3399 <CLADE extinct="1" name="Bavarisauridae" q="1"/>
3400 <CLADE name="Eublepharidae"/>
3401 <CLADE name="Gekkonoidea">
3402 <CLADE name="Gekkonidae" content="geckos"/>
3403 <CLADE name="Pygopodidae"/>
3406 <CLADE name="Autarchoglossa">
3407 <CLADE name="Scincomorpha">
3408 <CLADE name="Paramacellodidae"/>
3410 <CLADE name="Scinciformes" status="informal">
3411 <CLADE name="Scincoidea" status="informal">
3412 <CLADE name="Scincidae" content="skinks"/>
3413 <CLADE name="Feyliniidae"/>
3415 <CLADE name="Cordyliformes">
3416 <CLADE name="Cordylidae"/>
3417 <CLADE name="Gerrhosauridae"/>
3420 <CLADE name="Lacertiformes">
3421 <CLADE name="Xantusiidae"/>
3422 <CLADE name="Lacertoidea">
3423 <CLADE name="Lacertidae"/>
3425 <CGENUS extinct="1" name="Meyasaurus"/>
3426 <CLADE name="Teioidea">
3427 <CLADE name="Gymnophthalmidae"/>
3428 <CLADE name="Teiidae" content="whiptails"/>
3435 <CLADE name="Anguimorpha">
3436 <CSYNONYM name="Diploglossa"/>
3437 <CLADE extinct="1" name="Paravaranidae"/>
3438 <CLADE extinct="1" name="Bainguidae"/>
3440 <CLADE name="Anguidae" content="glass & alligator lizards"/>
3441 <CLADE name="Anniellidae"/>
3442 <CLADE extinct="1" name="Dorsetisauridae"/>
3443 <CLADE name="Xenosauridae"/>
3444 <CLADE name="Platynota">
3445 <CLADE extinct="1" name="Necrosauridae"/>
3446 <CLADE name="Thecoglossa">
3447 <CLADE name="Varanoidea">
3448 <CLADE name="Helodermatidae"/>
3450 <CLADE name="Lanthanotidae"/>
3451 <CLADE name="Varanidae" content="monitor lizards"/>
3454 <CLADE name="Pythonomorpha">
3455 <CLADE extinct="1" name="Mosasauroidea">
3456 <CGENUS extinct="1" name="Opetiosaurus"/>
3458 <CLADE extinct="1" name="Aigalosauridae"/>
3460 <CLADE extinct="1" name="Dolichosauridae"/>
3461 <CLADE extinct="1" name="Mosasauridae"/>
3465 <CLADE name="Ophidia" content="snakes">
3466 <CSYNONYM name="Serpentes"/>
3467 <CLADE name="Scolecophidia" q="1">
3468 <CLADE extinct="1" name="Anomalepedidae"/>
3469 <CLADE name="Leptotyphlopidae" content="slender blind snakes"/>
3470 <CLADE name="Typhlopidae" content="blind snakes"/>
3473 <CLADE extinct="1" name="Lapparentophidae"/>
3475 <CLADE extinct="1" name="Simoliophidae"/>
3476 <CLADE name="Booidea">
3477 <CLADE name="Boidae" content="constrictors"/>
3478 <CLADE extinct="1" name="Dinilysiidae" q="1"/>
3479 <CLADE extinct="1" name="Palaeophidae" q="1"/>
3480 <CLADE name="Pythonidae" content="pythons"/>
3482 <CLADE name="Alethinophidia">
3483 <CLADE name="Anilioidea">
3484 <CLADE name="Aniliidae"/>
3485 <CLADE name="Loxocemidae"/>
3486 <CLADE name="Uropeltidae"/>
3487 <CLADE name="Xenopeltidae"/>
3490 <CGENUS extinct="1" name="Ophiomorphus" q="1"/>
3491 <CGENUS extinct="1" name="Pachyrhachis" q="1"/>
3492 <CLADE name="Macrostomata">
3493 <CLADE name="Bolyeriidae"/>
3494 <CLADE name="Tropidophiidae"/>
3495 <CLADE name="Acrochordoidea">
3496 <CLADE name="Acrochordidae"/>
3497 <CLADE extinct="1" name="Nigerophidae"/>
3499 <CLADE name="Colubroidea">
3500 <CLADE extinct="1" name="Anomalophidae" q="1"/>
3501 <CLADE name="Colubridae" content="water, hognose, green, rat & earth snakes, etc."/>
3502 <CLADE extinct="1" name="Russelophidae" q="1"/>
3503 <CLADE name="Proteroglypha">
3504 <CLADE name="Elapidae" content="cobras, coral snakes"/>
3506 <CLADE name="Opisthoglypha">
3507 <CLADE name="Viperidae" content="vipers"/>
3532 <P> Lepidosauromorphs include all <LINK content="reptiles"/> with
3533 overlapping scales. Two types of lepidosauromorph remain alive today:
3534 <NOMEN nolink="1" name="Sphenodon"/> (tuatara) and the squamates
3535 (lizards and their descendants, snakes). </P>
3537 <P> During the late <LINK content="Mesozoic Era"/>, there were huge, marine
3538 squamates known as mosasaurs. They went extinct at the end of the
3539 <LINK content="Cretaceous"/>, along with all non-<LINK content="neornithean"/>
3540 <LINK content="dinosaurs"/>. </P>
3544 <TAXON name="Macronaria" nickname="Nasal-Crested Sauropods" silhouette="brachiosauridae">
3545 <WORD key="1" content="camarasaurs, brachiosaurs, big, huge, large, tallest, crested, biggest"/>
3546 <WORD essay="1" content="brachiosaur, brachiosaurs, camarasaur, Cetiosauridae"/>
3548 <CLADE name="Macronaria" in="Saltasaurus" out="Diplodocus" silhouette="macronaria">
3552 <AUTHOR name="Wilson, Sereno"/>
3553 <UNNAMED incertae="1" q="1">
3554 <REMAINS age="juvenile" content="specimens"/>
3555 <PLACE name="Germany"/>
3558 <CGENUS incertae="1" name="Abrosaurus" q="1"/>
3559 <CGENUS name="Aragosaurus" incertae="1"/>
3560 <CGENUS incertae="1" name="Bashunosaurus"/>
3561 <CGENUS name="Chondrosteosaurus" incertae="1"/>
3562 <CGENUS name="Lourinhasaurus" q="1" incertae="1"/>
3563 <CGENUS name="Sugiyamasaurus" incertae="1"/>
3564 <CLADE name="Camarasauromorpha" in="Camarasaurus, Saltasaurus">
3566 <NOMEN name="Camarasaurus"/> forms
3568 <CLADE name="Camarasauridae">
3569 <CGENUS name="Camarasaurus"/>
3571 <CLADE name="Titanosauriformes" in="Titanosaurus, Brachiosaurus">
3573 <NOMEN name="Titanosaurus"/> forms
3576 <REMAINS content="femur"/>
3577 <TIME value="Maastrichtian"/>
3578 <PLACE name="Egypt"/>
3580 <UNNAMED indet="1" q="1">
3582 <PLACE name="Australia"/>
3583 <REMAINS museum="QM" id="F6142" content="partial cervical vertebra"/>
3585 <UNNAMED cf="Pleurocoelus">
3586 <TIME value="Albian"/>
3587 <TIME value="Cenomanian" section="early"/>
3588 <PLACE name="Africa"/>
3591 <PLACE name="England"/>
3593 <CGENUS incertae="1" name="Austrosaurus" q="1"/>
3594 <CGENUS incertae="1" name="Bellusaurus" q="1"/>
3595 <CGENUS incertae="1" name="Bothriospondylus"/>
3596 <CGENUS name="Damalasaurus" incertae="1" q="1"/>
3597 <CGENUS incertae="1" name="Ischyrosaurus"/>
3598 <CGENUS incertae="1" name="Ornithopsis"/>
3599 <CGENUS incertae="1" name="Pelorosaurus"/>
3600 <CGENUS name="Astrodon" q="1"/>
3601 <CGENUS q="1" name="Atlasaurus" silhouette="brachiosauridae"/>
3602 <CGENUS name="Cedarosaurus"/>
3603 <CGENUS name="Eucamerotus" q="1"/>
3604 <CGENUS name="Giraffatitan" silhouette="brachiosauridae"/>
3605 <CGENUS name="Pleurocoelus" q="1"/>
3606 <CGENUS name="Sauroposeidon" silhouette="brachiosauridae"/>
3607 <CGENUS name="Sonorasaurus"/>
3608 <CLADE name="Brachiosauridae" silhouette="brachiosauridae">
3609 <CGENUS name="Brachiosaurus"/>
3611 <CLINK name="Titanosauria"/>
3616 <CLADOGRAM alternate="1">
3617 <CLADE name="Macronaria">
3618 <CGENUS name="Haplocanthosaurus"/>
3619 <CLADE name="Camarasauromorpha">
3620 <CGENUS name="Camarasaurus"/>
3621 <CLADE name="Titanosauriformes">
3622 <CLADE name="Brachiosauridae"/>
3623 <CLADE name="Somphospondyli" in="Saltasaurus, Euhelopus">
3624 <CGENUS name="Euhelopus"/>
3625 <CLADE name="Titanosauria"/>
3631 <CLADOGRAM alternate="1">
3634 <CGENUS name="Haplocanthosaurus"/>
3635 <CGENUS name="Andesaurus"/>
3637 <CLADE name="Titanosauroidea" sensu="Sanz, J. Powell, Le Loeuff, Martinez, Pereda-Suberbiola" year="1999">
3638 <CGENUS name="Opisthocoelicaudia"/>
3639 <CLADE name="Titanosauria" sensu="Sanz, J. Powell, Le Loeuff, Martinez, Pereda-Suberbiola" year="1999"/>
3644 <P> The name Macronaria ("large nostrils") refers to the enlarged nasal
3645 openings of this group. Like all <LINK content="sauropods"/>, their nostrils
3646 were situated atop their head, nearly above the eyes. Macronarians
3647 had crests of varying sizes formed by high nasal bones. In some
3648 specimens, these bones were not completely preserved, leaving the skull
3649 looking rather low, like those of <LINK content="diplodocimorphs"/>. For this
3650 reason, many were once classified with them. </P>
3652 <P header='"Camarasaurs"'> Basal (non-titanosauriform) macronarians, or
3653 "camarasaurs", were fairly typical sauropods of small to average size.
3654 They had boxy skulls and spatulate teeth. Embryonic "camarasaur" material
3655 indicates that some laid eggs with diameters of 24 cm. </P>
3657 <P header='"Brachiosaurs"'> Most of the animals listed above as
3658 non-titanosaurian titanosauriforms have been included at some time in the
3659 family Brachiosauridae, but their exact relations to one another are
3660 poorly understood at this time. Among these animals are some of the
3661 largest land animals of all time, such as <NOMEN name="Brachiosaurus"/>,
3662 <NOMEN name="Giraffatitan"/>, and the new <NOMEN name="Sauroposeidon"/>.
3663 Some had very high nasal crests and forelimbs longer than hindlimbs. </P>
3665 <P> It was once thought that the large crest of "brachiosaurs" was a
3666 snorkeling device. Since then it has been shown that if a
3667 <NOMEN name="Brachiosaurus"/> were to be submerged at such a depth as to
3668 need a raised blowhole on its head, the pressure on its chest would be so
3669 great that its lungs would collapse. Instead, it is likely that
3670 "brachiosaurs", and probably all sauropods, were terrestrial. </P>
3674 <TAXON name="Mammalia" nickname="Furry Milksuckers" simple="1">
3675 <WORD key="1" content="mammals, multis"/>
3676 <WORD essay="1" content="bat, bats, human, mammal, glyptodont, mammalian bats, sirenians, walruses"/>
3677 <INCLUDED content="Antidorcas, Giraffa, Homo, Bison, Zalambdalestes"/>
3679 <CLADE name="Mammalia" sensu="stricto" crown="1" silhouette="mammalia">
3680 <CLADE name="Prototheria" in="Monotremata" out="Theria">
3684 <CLADE name="Monotremata" crown="1" content="duck-bill platypuses, echidnas (or spiny anteaters)">
3690 <CLADE extinct="1" name="Allotheria" q="1">
3691 <CLADE extinct="1" name="Haramiyidae"/>
3692 <CLADE extinct="1" name="Multituberculata" content='"multis"'/>
3694 <CLADE name="Theriiformes" in="Theria" out="Monotremata">
3698 <CLADE extinct="1" name="Triconodonta">
3699 <CLADE name="Holotheria">
3700 <CLADE extinct="1" name="Chronoperatidae" q="1"/>
3701 <CLADE extinct="1" name="Kuehnotheria">
3702 <CLADE name="Trechnotheria">
3703 <CSYNONYM name="Yangotheria"/>
3704 <CLADE extinct="1" name="Spalacotherioidea"/>
3705 <CLADE name="Symmetrodonta">
3709 <CLADE extinct="1" name="Yinotheria"/>
3710 <CLADE name="Cladotheria">
3714 <CLADE extinct="1" name="Dryolestoidea"/>
3715 <CLADE name="Amphitheriida">
3716 <CLADE extinct="1" name="Amphitheriidae"/>
3717 <CLADE name="Zatheria">
3718 <CLADE extinct="1" name="Arguimuridae"/>
3719 <CLADE extinct="1" name="Arguitheriidae"/>
3720 <CLADE extinct="1" name="Vincelestidae"/>
3722 <CLADE extinct="1" name="Paramura"/>
3723 <CLADE name="Tribosphenida">
3724 <CGENUS extinct="1" name="Hypomylos"/>
3725 <CLADE extinct="1" name="Necrolestidae"/>
3727 <CLADE extinct="1" name="Aegialodontia"/>
3728 <CLADE name="Theria" sensu="stricto">
3732 <CGENUS extinct="1" name="Aethomylos" q="1"/>
3733 <CGENUS extinct="1" name="Anizorhinus" q="1"/>
3734 <CGENUS extinct="1" name="Dakotadens" q="1"/>
3735 <CGENUS extinct="1" name="Falepterus" q="1"/>
3736 <CGENUS extinct="1" name="Kasserinotherium" q="1"/>
3737 <CGENUS extinct="1" name="Paleomolops" q="1"/>
3738 <CGENUS extinct="1" name="Plicatodon" q="1"/>
3739 <CGENUS extinct="1" name="Potamotelses" q="1"/>
3740 <CGENUS extinct="1" name="Russellmys" q="1"/>
3741 <CGENUS extinct="1" name="Tetraprothomo" q="1"/>
3742 <CGENUS extinct="1" name="Tribotherium" q="1"/>
3743 <CGENUS extinct="1" name="Zygiocuspis" q="1"/>
3744 <CLADE extinct="1" name="Endotheriidae"/>
3745 <CLADE extinct="1" name="Kermackiidae"/>
3746 <CLADE extinct="1" name="Picopsidae"/>
3747 <CLADE extinct="1" name="Poppotheriidae"/>
3748 <CLADE name="Metatheria" content="pouched mammals" in="Marsupialia" out="Placentalia">
3752 <CGENUS extinct="1" name="Holoclemensia"/>
3753 <CLADE extinct="1" name="Deltatheridioidea"/>
3755 <CGENUS extinct="1" name="Monodelphis" q="1"/>
3756 <CLADE extinct="1" name="Boreometatheria" q="1" content="Asian & North American pouched mammals">
3761 <CLADE name="Notometatheria" content="Australasian & South American pouched mammals">
3765 <CLADE extinct="1" name="Protodidelphidae" q="1"/>
3766 <CLADE extinct="1" name="Borhyaenoidea" content="Borhyaena, Thylacosmilus, etc.">
3767 <CSYNONYM name="Sparassodonta"/>
3769 <CLADE extinct="1" name="Bonabartheriidae" q="1"/>
3770 <CLADE extinct="1" name="Necrolestidae" q="1"/>
3771 <CLADE extinct="1" name="Paradectidae" q="1"/>
3772 <CLADE extinct="1" name="Simpsonitheria" q="1"/>
3774 <CGENUS extinct="1" name="Mayulestes"/>
3776 <CGENUS extinct="1" name="Pucadelphys"/>
3778 <CGENUS extinct="1" name="Andinodelphys"/>
3779 <CLADE name="Marsupialia" crown="1">
3783 <CLADE name="Didelphimorpha" content="American opossums"/>
3784 <CLADE name="Paucituberculata" q="1" content="rat opossums"/>
3786 <CLADE name="Microbiotheriidae" content="monitos del monte"/>
3787 <CLADE extinct="1" name="Yingabalanaridae" q="1"/>
3788 <CLADE name="Australidelphia" content="Australasian marsupials">
3792 <CSYNONYM name="Eometatheria" q="1"/>
3793 <CLADE name="Dasyuromorpha" content="marsupial mice & rats, quolls, Tasmanian wolves & devils, numbats"/>
3794 <CLADE name="Notoryctidae" q="1" content="marsupial moles"/>
3795 <CLADE name="Tarsipedidae" q="1" content="honey possums"/>
3796 <CLADE extinct="1" name="Yalkaperidontidae" q="1"/>
3797 <CLADE name="Syndactyla">
3801 <CLADE name="Peramelomorpha" content="bandicoots"/>
3802 <CLADE name="Diprotodonta">
3804 <NOMEN nolink="1" name="Diprotodon"/>'s <LOW>taxon</LOW>
3809 <CLADE extinct="1" name="Palorchestidae" q="1"/>
3810 <CLADE extinct="1" name="Thylacoleonidae" q="1" content="marsupial lions"/>
3811 <CLADE extinct="1" name="Wynyardiidae" q="1"/>
3812 <CLADE name="Vombatiformes" comment="wombats, koalas"/>
3813 <CLADE name="Phalangeriformes" comment="phalangers, kangaroos, etc."/>
3825 <CLADE name="Eutheria" in="Placentalia" out="Marsupialia">
3829 <CGENUS extinct="1" name="Prokennalestes"/>
3830 <CLADE name="Placentalia" status="informal" crown="1" content="placental mammals">
3834 <CGENUS extinct="1" name="Aspanlestes" q="1"/>
3835 <CGENUS extinct="1" name="Bulaklestes" q="1"/>
3836 <CGENUS extinct="1" name="Beleutinus" q="1"/>
3837 <CGENUS extinct="1" name="Daulestes" q="1"/>
3838 <CGENUS extinct="1" name="Eodesmatodon" q="1"/>
3839 <CGENUS extinct="1" name="Eutrochodon" q="1"/>
3840 <CGENUS extinct="1" name="Helioseus" q="1"/>
3841 <CGENUS extinct="1" name="Idiogenomys" q="1"/>
3842 <CGENUS extinct="1" name="Kumsuperus" q="1"/>
3843 <CGENUS extinct="1" name="Neodesmostylus" q="1"/>
3844 <CGENUS extinct="1" name="Obtususdon" q="1"/>
3845 <CGENUS extinct="1" name="Sorlestes" q="1"/>
3846 <CGENUS extinct="1" name="Telacodon" q="1"/>
3847 <CGENUS extinct="1" name="Tingamarra" q="1"/>
3848 <CGENUS extinct="1" name="Veratalpa" q="1"/>
3849 <CGENUS extinct="1" name="Wanotherium" q="1"/>
3850 <CLADE extinct="1" name="Bibimalagasia" q="1"/>
3851 <CLADE name="Edentata" in="Xenarthra" out="Carnivora, Ungulata, Anagalida, Archonta, Insectivora">
3855 <CLADE name="Pholidota" q="1" content="pangolins or scaly anteaters"/>
3857 <CLADE extinct="1" name="Palaeanodonta" q="1"/>
3858 <CLADE name="Xenarthra" crown="1" content="sloths, anteaters, armadillos"/>
3861 <CLADE name="Epitheria" in="Carnivora, Ungulata, Anagalida, Archonta, Insectivora" out="Xenarthra">
3865 <CLADE extinct="1" name="Apatotheria" incertae="1"/>
3866 <CLADE extinct="1" name="Asioryctitheria"/>
3867 <CLADE extinct="1" name="Cimolestidae" incerate="1"/>
3868 <CLADE extinct="1" name="Leptictida" incertae="1"/>
3869 <CLADE extinct="1" name="Palaeoryctidae" incertae="1"/>
3870 <CLADE extinct="1" name="Pantodonta"/>
3871 <CLADE extinct="1" name="Pantolesta"/>
3872 <CLADE extinct="1" name="Taeniodonta" incertae="1"/>
3873 <CLADE extinct="1" name="Tillodonta" incertae="1"/>
3874 <CLADE extinct="1" name="Zalambdalestidae"/>
3875 <CLADE name="Insectivora" crown="1" content="shrews, moles, tenrecs, golden moles, hedgehogs, etc.">
3879 <CSYNONYM name="Lipotyphla"/>
3881 <CLADE name="Ferae">
3883 fierce <LOW>ones</LOW>
3885 <CLADE extinct="1" name="Creodonta"/>
3886 <CLADE name="Carnivoramorpha" in="Carnivora" out="Creodonta">
3890 <CLADE extinct="1" name="Didymictidae"/>
3891 <CLADE name="Carnivora" crown="1" content="dogs, bears, weasels, seals, cats, hyenas, mongooses, etc.">
3892 <MEANING>meat-eaters</MEANING>
3896 <CLADE name="Archonta" crown="1">
3900 <CLADE name="Chiropteromorpha" status="informal" in="Chiroptera" out="Primates">
3904 <CLADE name="Chiroptera" content="bats">
3909 <CLADE name="Dermoptera" q="1" content="colugos or flying lemurs">
3915 <CLADE name="Primatomorpha" in="Primates" out="Chiroptera">
3919 <CLADE name="Scandentia" q="1" content="tree shrews"/>
3921 <CLADE extinct="1" name="Plesiadapiformes" q="1"/>
3922 <CLADE name="Primates" crown="1" content="apes, humans, lemurs, lorises, monkeys, etc.">
3924 primary <LOW>ones</LOW>
3930 <CLADE name="Anagalida" crown="1">
3931 <CLADE name="Macroscelidea" content="elephant shrews">
3937 <CLADE extinct="1" name="Anagaloidea"/>
3938 <CLADE name="Glires" in="Lagomorpha, Rodentia">
3939 <CLADE name="Duplicidentata" in="Lagomorpha" out="Rodentia">
3940 <CLADE extinct="1" name="Mimotonida"/>
3941 <CLADE name="Lagomorpha" crown="1" content="rabbits, hares, pikas">
3943 <NOMEN nolink="1" name="Lagus"/> <LOW>(rabbit)</LOW> forms
3947 <CLADE name="Simplicidentata" in="Rodentia" out="Lagomorpha">
3948 <CGENUS extinct="1" name="Eurymylus"/>
3949 <CGENUS extinct="1" name="Matutinia"/>
3950 <CGENUS extinct="1" name="Rhombomylus"/>
3951 <CLADE name="Rodentomorpha">
3955 <CGENUS extinct="1" name="Helomys"/>
3956 <CLADE name="Rodentiformes">
3960 <CGENUS extinct="1" name="Tribosphenomys"/>
3961 <CLADE name="Rodentia" crown="1" content="rodents"/>
3968 <CLADE name="Ungulatamorpha" in="Ungulata" out="Carnivora, Archonta, Anagalida, Insectivora">
3972 <CGENUS extinct="1" name="Aspanlestes"/>
3974 <CGENUS extinct="1" name="Avitotherium"/>
3976 <CGENUS extinct="1" name="Alostera"/>
3978 <CLADE extinct="1" name="Zenlestidae"/>
3980 <CSYNONYM name="Ungulata" sensu="lato"/>
3981 <CLADE extinct="1" name="Dinocerata" q="1" content="Uintatherium, etc."/>
3982 <CLADE extinct="1" name="Oxyclaenidae"/>
3983 <CLADE name="Ungulata" crown="1" content="hoofed mammals, etc.">
3987 <CLADE extinct="1" name="Arctocyonidae"/>
3988 <CLADE extinct="1" name="Arctostylopidae"/>
3989 <CLADE extinct="1" name="Paroxyclaenidae"/>
3990 <CLADE extinct="1" name="Tricuspiodontidae"/>
3991 <CLADE name="Tubulidentata" content="aardvarks">
3997 <CLADE extinct="1" name="Mioclaenidae"/>
3998 <CLADE extinct="1" name="Periptychidae"/>
4000 <CLADE extinct="1" name="Meridiungulata" content="extinct South American ungulates">
4001 <CLADE extinct="1" name="Didolodontidae"/>
4003 <CLADE name="Astrapotheria" q="1" extinct="1"/>
4004 <CLADE name="Litopterna" content="Macrauchenia, etc." extinct="1"/>
4006 <CLADE name="Pyrotheria" q="1"/>
4007 <CLADE name="Xenungulata"/>
4009 <CLADE name="Notoungulata">
4013 <CLADE extinct="1" name="Notoprongonia"/>
4014 <CLADE extinct="1" name="Toxodontia"/>
4015 <CLADE extinct="1" name="Typotheria"/>
4019 <CLADE name="Mesaxonia">
4020 <CSYNONYM name="Altungulata"/>
4021 <CSYNONYM name="Paenungulata" q="1"/>
4022 <CSYNONYM name="Penungulata" q="1"/>
4024 <CLADE extinct="1" name="Meniscotheriidae"/>
4026 <CLADE extinct="1" name="Phenacodontidae"/>
4028 <CLADE extinct="1" name="Embrithopoda" content="large, double-horned herbivores"/>
4030 <CLADE name="Hyracoidea" q="1" content="hyraxes"/>
4031 <CLADE name="Perissodactyla" content="horses, rhinos, tapirs, brontotheriids, chalicotheriids, etc.">
4033 odd <LOW>number of</LOW> fingers
4041 <CLADE extinct="1" name="Loxolophidae"/>
4043 <CLADE extinct="1" name="Phenacolophidae"/>
4044 <CLADE name="Tethytheria" in="Sirenia, Elephantidae">
4046 Tethys <LOW>Sea</LOW> beasts
4048 <CLADE name="Sirenia" content="manatees, dugongs, sea cows">
4050 sirens <LOW>(alluring marine creatures of Greek mythology)</LOW>
4054 <CLADE extinct="1" name="Desmostylia" content="hippo-like amphibious ungulates">
4059 <CLADE name="Proboscidea" content="elephants, mammoths, etc.">
4069 <CLADE name="Paraxonia">
4070 <CLADE extinct="1" name="Triisodontidae"/>
4072 <CLADE name="Artiodactyla" crown="1" content="pigs, hippos, deer, giraffes, antelope, cattle, goats, sheep, etc.">
4074 even<LOW> number of</LOW> fingers
4077 <CLADE name="Cete" in="Cetacea" out="Artiodactyla">
4081 <CLADE extinct="1" name="Hapalodectidae"/>
4083 <CLADE extinct="1" name="Mesonychidae">
4084 <CLADE name="Cetacea" content="whales" sensu="lato">
4085 <CLADE extinct="1" name="Protocetidae"/>
4086 <CLADE extinct="1" name="Remingtonocetidae" q="1"/>
4088 <CLADE extinct="1" name="Basilosauridae" content="serpent whales">
4089 <CSYNONYM name="Zeuglodontidae"/>
4091 <CLADE name="Autoceta" content="modern whales">
4092 <CSYNONYM name="Cetacea" crown="1" sensu="stricto"/>
4125 <CLADOGRAM alternate="1">
4126 <CLADE name="Eutheria">
4127 <CLADE name="Erinaceomorpha" q="1" content="hedgehogs"/>
4129 <CLADE name="Atlantogenata">
4130 <CLADE name="Xenarthra"/>
4131 <CLADE name="Afrotheria">
4132 <MEANING>African beasts</MEANING>
4133 <CLADE name="Afrosoricida"" content="tenrecs, golden moles, etc.">
4134 <MEANING>African shrews</MEANING>
4136 <CLADE name="Macroscelidea"/>
4137 <CLADE name="Pseudungulata">
4138 <CLADE name="Tubulidentata"/>
4139 <CLADE name="Paenungulata">
4140 <CSYNONYM name="Uranotheria"/>
4141 <CLADE name="Hyracoidea"/>
4142 <CLADE name="Tethytheria"/>
4148 <CLADE name="Glires"/>
4149 <CLADE name="Euarchonta">
4150 <CLADE name="Dermoptera" q="1"/>
4151 <CLADE name="Primatomorpha"/>
4153 <CLADE name="Laurasiatheria">
4154 <MEANING>Laurasian beasts</MEANING>
4155 <CLADE name="Eulipotyphla" content="shrews & moles"/>
4156 <CLADE name="Scrotifera">
4157 <CLADE name="Chiroptera"/>
4158 <CLADE name="Fereuungulata">
4159 <CLADE name="Zooamata">
4160 <MEANING>animal friends</MEANING>
4161 <CLADE name="Carnivora"/>
4162 <CLADE name="Perissodactyla"/>
4163 <CLADE name="Pholidota"/>
4165 <CLADE name="Artiodactyla">
4166 <CSYNONYM name="Cetartiodactyla"/>
4167 <CSYNONYM name="Paraxonia" q="1"/>
4168 <CLADE name="Tylopoda" content="camels, llamas, etc."/>
4170 <CLADE name="Suoidea" content="pigs, peccaries"/>
4172 <CLADE name="Ruminantia" content="deer, giraffes, antelope, cattle, goats, sheep, etc."/>
4173 <CLADE name="Whippomorpha">
4174 <MEANING>wh<LOW>ale-h</LOW>ippo forms</MEANING>
4175 <CLADE name="Hippopotamoidea" content="hippopotami, etc."/>
4176 <CLADE name="Cetacea" sensu="lato"/>
4189 <P> Mammals originated around the same time as the
4190 <LINK content="dinosaurs"/>, but remained in their shadow throughout the
4191 <LINK content="Mesozoic"/>. After the K/T extinction, they diversified to
4192 fit the niches that the dinosaurs left empty, as well as many other niches.
4193 Go us! Dinosaurs may be cool, but who's on top of the food chain now, eh?
4194 I have to go eat some <LINK content="chicken"/>. </P>
4198 <TAXON name="Neoceratosauria" nickname="Primitive Predators With Big Teeth">
4199 <WORD key="1" content="predator, carnotaur, horned, horns, carnivore, carnivorous, meat"/>
4201 <CLADE name="Neoceratosauria" in="Ceratosaurus" out="Coelophysis" silhouette="neoceratosauria">
4205 <AUTHOR name="Novas" year="1991"/>
4206 <CSYNONYM name="Ceratosauroidea" sensu="Sereno" year="1999"/>
4207 <CGENUS incertae="1" name="Dandakosaurus" q="1"/>
4208 <CGENUS incertae="1" name="Genusaurus"/>
4209 <CGENUS name="Sarcosaurus"/>
4211 <CGENUS name="Ceratosaurus"/>
4212 <CLADE name="Abelisauroidea" in="Carnotaurus" out="Ceratosaurus, Elaphrosaurus" silhouette="abelisauroidea">
4213 <AUTHOR name="Bonaparte" year="1991"/>
4214 <AUTHOR type="implied" name="Bonaparte, Novas" year="1985"/>
4215 <CGENUS incertae="1" name="Compsosuchus"/>
4216 <CGENUS name="Dryptosauroides" incertae="1"/>
4217 <CGENUS incertae="1" name="Genyodectes"/>
4218 <CGENUS name="Jubbulpuria" incertae="1"/>
4219 <CGENUS name="Ornithomimoides" incertae="1"/>
4220 <CGENUS incertae="1" name="Tarascosaurus"/>
4221 <CGENUS name="Ilokelesia" q="1"/>
4222 <CGENUS name="Laevisuchus" silhouette="abelisauroidea-small"/>
4223 <CGENUS name="Ligabueino" silhouette="abelisauroidea-small"/>
4224 <CGENUS name="Velocisaurus" silhouette="abelisauroidea-small"/>
4225 <CLADE name="Abelisauria" in="Abelisaurus, Noasaurus">
4227 <NOMEN name="Abelisaurus"/>' <LOW>taxon</LOW>
4229 <CGENUS name="Noasaurus" silhouette="noasaurus"/>
4230 <CLADE name="Abelisauridae" in="Abelisaurus, Carnotaurus, Indosaurus, Indosuchus, Xenotarsosaurus">
4231 <AUTHOR name="Bonaparte, Novas" year="1985"/>
4232 <AUTHOR type="sensu" name="Novas" year="1997"/>
4233 <CGENUS incertae="1" name="Indosaurus"/>
4234 <CGENUS incertae="1" name="Xenotarsosaurus"/>
4235 <CGENUS name="Indosuchus"/>
4236 <CLADE name="Abelisaurinae" in="Abelisaurus" out="Carnotaurus">
4237 <AUTHOR type="sensu" name="Sereno" year="1999"/>
4238 <AUTHOR type="implied" name="Bonaparte, Novas" year="1985"/>
4239 <CGENUS name="Abelisaurus"/>
4241 <CLADE name="Carnotaurinae" in="Carnotaurus" out="Abelisaurus" silhouette="carnotaurinae">
4242 <AUTHOR name="Sereno" year="1999"/>
4244 <TIME value="Cenomanian"/>
4245 <PLACE name="Argentina"/>
4247 <CGENUS incertae="1" name="Majungasaurus" q="1"/>
4248 <CGENUS name="Carnotaurus"/>
4249 <CGENUS name="Majungatholus"/>
4257 <CLADOGRAM alternate="1">
4258 <CLADE name="Abelisauroidea">
4259 <CLADE name="Carcharodontosauridae"/>
4260 <CLADE name="Abelisauria"/>
4264 <P> These were mostly medium-large predators which displayed some primitive
4265 characteristics, such as four manual digits, one of which was lost in
4266 the more "advanced" <LINK content="tetanurans"/>, the other great branch of
4267 <LINK content="theropods"/>. Although never quite as diverse (or numerous) as the
4268 tetanurans, neoceratosaurs had some variety. Most were medium-large
4269 predators, but there were also tiny ones like
4270 <NOMEN name="Ligabueino"/> and <NOMEN name="Velocisaurus"/>.
4271 <NOMEN name="Noasaurus"/> seems to have had a large "sickle claw" on
4272 each foot, like the tetanuran <LINK content="troodontids"/> and
4273 <LINK content="deinonychosaurs"/>. Many neoceratosaurs had ornate horns on
4274 their heads, like <NOMEN name="Ceratosaurus"/> and the carnotaurines. </P>
4276 <P> Neoceratosaurs were generally robust with "tall" heads. Some had a small
4277 opening in front of the antorbital fenestra, similar but probably
4278 convergent to the maxillary fenestra of tetanurans. Neoceratosaurs had six
4279 or seven fused sacral vertebrae, more than other theropods. </P>
4281 <P> During the <LINK content="Cretaceous"/>, neoceratosaurs inhabited the southern, or Gondwanan,
4282 continents. If, as a few suspect, the mighty <LINK content="carcharodontosaurines"/>
4283 are abelisauroids, they may have even been the dominant Gondwanan predators
4284 (although it seems more likely that they are
4285 <LINK content="allosauroids"/>). Neoceratosaurs persisted to the end of the
4286 <LINK content="Mesozoic Era"/>. </P>
4290 <TAXON name="Neornithes" nickname="Modern Birds" simple="1">
4291 <WORD key="1" content="bird, modern, classification, cladogram, evolution, feather, flight, origin, Diatryma"/>
4292 <WORD essay="1" content="chicken, modern bird, modern birds, modern flying birds, modern-day birds, neornithean birds, ostriches, penguins, sparrow, songbird, trochilid, trochilids"/>
4293 <INCLUDED content="Aegotheles, Aquila, Aratinga, Casuarius, Ceratogymna, Gastornis, Dinornis, Dromaius, Opisthocomo, Pavo, Pelagornis, Sagittarius, Scaniornis, Tyto"/>
4295 <CLADE name="Neornithes" crown="1" silhouette="neornithes">
4299 <CSYNONYM name="Aves" sensu="Gauthier" year="1986"/>
4300 <CLADE name="Palaeognathae" in="Ratitae" out="Passeriformes">
4304 <CSYNONYM name="Palaeognathia"/>
4305 <CSYNONYM name="Eoaves"/>
4306 <CGENUS incertae="1" name="Eremopezus"/>
4307 <CGENUS incertae="1" name="Remiornis"/>
4308 <CGENUS incertae="1" name="Stromeria"/>
4309 <CLADE extinct="1" name="Eleutherornithidae" q="1"/>
4310 <CLADE name="Tinamiformes" content="tinamous">
4312 <NOMEN name="Tinamus" nolink="1"/> (tinamou) forms
4315 <CLADE name="Ratitae" in="Apteryx, Struthio">
4316 <CSYNONYM name="Ratiti"/>
4317 <CLADE name="Apteryges" in="Apteryx" out="Struthio">
4318 <CLADE name="Apterygiformes" content="kiwis"/>
4319 <CLADE extinct="1" name="Dinornithiformes" q="1" content="moa"/>
4320 <CLADE extinct="1" name="Dromornithiformes" q="1" content="mihirung"/>
4322 <CLADE name="Struthiones" in="Struthio" out="Apteryx">
4323 <CLADE extinct="1" name="Aepyornithiformes" content="elephant birds"/>
4325 <CLADE name="Casuariiformes" content="cassowaries, emus"/>
4327 <CLADE name="Rheiformes" content="rheas"/>
4329 <CLADE extinct="1" name="Lithornithiformes" q="1"/>
4330 <CLADE name="Struthioniformes" content="ostriches"/>
4337 <CLADE name="Neognathae" in="Passeriformes" out="Ratitae">
4341 <CSYNONYM name="Neognathia"/>
4342 <CSYNONYM name="Neoaves"/>
4343 <CLADE name="Galloanserae">
4345 <NOMEN nolink="1" name="Gallus"/>' <LOW>(chicken) and</LOW> <NOMEN nolink="1" name="Anser"/>'s <LOW>(duck) taxon</LOW>
4347 <CLADE name="Anseriformes" q="1" content="ducks, geese, swans, screamers, Presbyornis, Gastornis?"/>
4348 <CLADE name="Galliformes" q="1" content="turkeys, grouse, quails, pheasants, peafowl, etc."/>
4351 <CLADE name="Mesitornithidae"/>
4353 <CLADE name="Ardeidae" q="1" content="herons"/>
4354 <CLADE name="Eurypygoidea"/>
4355 <CLADE name="Otides"/>
4356 <CLADE name="Rhynchoceti" q="1"/>
4357 <CLADE name="Gruimorphae">
4358 <CLADE name="Gruiformes" content="cranes, rails, etc."/>
4359 <CLADE name="Podicepiformes" q="1" content="grebes"/>
4361 <CLADE name="Charadriomorphae">
4362 <CLADE extinct="1" name="Graculavidae"/>
4363 <CLADE name="Ciconiimorphae">
4364 <CLADE name="Phoenicopteriformes" content="flamingos"/>
4366 <CLADE name="Ciconiiformes" content="storks, spoonbills?, New World vultures?, etc."/>
4368 <CLADE name="Pelecaniformes" content="pelicans, frigate birds, gannets, boobies, cormorants, anhingas, etc."/>
4370 <CLADE name="Procellariformes" content="albatrosses, petrels, shearwaters, etc."/>
4372 <CLADE name="Gaviiformes" content="loons"/>
4373 <CLADE name="Sphenisciformes" content="penguins"/>
4380 <CLADE name="Burnithidae"/>
4381 <CLADE name="Charadriiformes">
4382 <CLADE status="informal" name="Charadriida" content="avocets, etc."/>
4383 <CLADE name="Phalaropodidae" q="1" content="phalaropes"/>
4384 <CLADE name="Scolopacida" status="informal" content="jacanas, etc."/>
4386 <CLADE name="Laridae"/>
4387 <CLADE name="Sternidae" q="1"/>
4390 <CLADE name="Stercorariidae"/>
4391 <CLADE name="Dromadidae"/>
4394 <CLADE name="Turnicidae" content="button quails"/>
4396 <CLADE name="Pteroclidiformes"/>
4398 <CLADE name="Columbiformes" content="pigeons, doves, sandgrouse, dodo"/>
4399 <CLADE name="Psittaciformes" content="cockatoos, parrots"/>
4407 <CLADE name="Cariamae" content="phorusrhacids, etc"/>
4410 <CLADE name="Falconiformes" content="falcons, caracaras" q="1"/>
4411 <CLADE name="Opisthocomiformes" q="1" content="hoatzins, Foro?"/>
4414 <CLADE name="Cuculiformes" q="1" content="cuckoos, etc."/>
4416 <CLADE name="Pandionidae" q="1" content="ospreys"/>
4417 <CLADE name="Sagittariidae" q="1" comment="secretary birds"/>
4419 <CLADE name="Musophagiformes" q="1" content="turacos, etc."/>
4420 <CLADE name="Accipitriformes" q="1" content="hawks, eagles, Old World vultures, Horusornis?"/>
4422 <CLADE name="Anomalogonatae">
4423 <CGENUS incertae="1" name="Zygodactylus"/>
4424 <CLADE name="Coliiformes" content="mousebirds"/>
4425 <CLADE extinct="1" name="Sandcoleiformes"/>
4427 <CLADE name="Strigiformes" content="owls"/>
4429 <CLADE name="Apodiformes" content="swifts, hummingbirds"/>
4430 <CLADE name="Caprimulgiformes" content="goatsuckers"/>
4434 <CLADE name="Coraciiformes" content="rollers, courols, etc."/>
4436 <CLADE name="Trogoniformes" content="trogons, todies, motmots, bee eaters, kingfishers, etc."/>
4437 <CLADE name="Bucerotimorphae">
4438 <CLADE name="Bucerotiformes" content="hornbills, hoopoes, etc."/>
4440 <CLADE name="Piciformes" content="barbets, toucans, woodpeckers, etc."/>
4441 <CLADE name="Passeriformes" content="songbirds, etc."/>
4457 <P> This group contains all modern, toothless <LINK content="birds"/>.
4458 They are divided into paleognathans (ratites and tinamous) and neognathans
4459 (all other modern birds). Beyond that, classification gets tricky --
4460 there are about as many schemes as there are scientists studying avian
4461 phylogeny. Neornithean systematics is highly volatile at the moment, so
4462 don't be surprised if you see changes here. </P>
4464 <P header="Survivors"> When all the other <LINK content="dinosaurs"/> died
4465 out at the end of the <LINK content="Cretaceous Period"/>, neornithean
4466 birds made an attempt to fill the empty niches left by the large predatory
4467 <LINK content="theropods"/>. In South America, large, ground-dwelling,
4468 carnivorous phorusrhacids evolved and lasted until fairly recently. But
4469 today, with few exceptions, birds are aerial, not terrestrial. </P>
4471 <P> In the skies, however, these last descendants of the mighty dinosaurs
4472 still reign supreme. They beat out <LINK content="pterosaurs"/> in the
4473 <LINK content="Mesozoic"/> (in the smaller niches) and today they keep
4474 <LINK content="mammalian bats"/> from flying during the day. There are over
4475 twice as many living species of bird as living species of mammal. They are
4476 the last vestige of the dinosaurs' dominion. </P>
4480 <TAXON name="Ornithischia" nickname='Beaked, "Bird-Hipped" Plant-Eaters'>
4481 <WORD key="1" content="bird-hipped, bird, hipped, hips, pelvis, pelves, herbivorous, herbivores, plant, plant-eating, vegetarian, veggie, vegetable"/>
4482 <WORD essay="1" content="genasaurian ornithischian, fabrosaurid"/>
4484 <CLADE name="Ornithischia" in="Triceratops" out="Neornithes" silhouette="ornithischia">
4485 <AUTHOR name="Seeley" year="1888"/>
4486 <AUTHOR type="sensu" name="Padian, May" year="1993"/>
4488 bird<LOW>-like</LOW> ischia
4490 <CSYNONYM name="Predentata"/>
4491 <CSYNONYM name="Orthopoda"/>
4492 <UNNAMED comment="primitive">
4493 <TIME value="Carnian"/>
4494 <TIME value="Norian"/>
4495 <PLACE name="New Mexico"/>
4497 <UNNAMED comment="large, primitive">
4498 <PLACE name="S. Africa"/>
4500 <CGENUS incertae="1" name="Alocodon"/>
4501 <CGENUS incertae="1" name="Lucianosaurus"/>
4502 <CGENUS incertae="1" name="Revueltosaurus"/>
4503 <CGENUS incertae="1" name="Technosaurus"/>
4504 <CGENUS incertae="1" name="Tecovasaurus"/>
4505 <CGENUS incertae="1" name="Trimucrodon"/>
4506 <CGENUS incertae="1" name="Xiaosaurus"/>
4507 <CGENUS name="Galtonia"/>
4508 <CGENUS name="Pekinosaurus"/>
4509 <CGENUS name="Pisanosaurus"/>
4511 <UNNAMED incertae="1" cf="Echinodon">
4512 <TIME value="Kimmeridgian" section="late"/>
4513 <PLACE name="Colorado"/>
4514 <REMAINS content="limb elements, etc."/>
4515 <REMAINS content="right dentary, left maxilla" q="1"/>
4517 <CGENUS name="Agilisaurus" incertae="1"/>
4518 <CGENUS name="Fabrosaurus"/>
4519 <CGENUS name="Gongbusaurus" q="1"/>
4520 <CGENUS name="Lesothosaurus"/>
4521 <CLADE name="Genasauria" in="Triceratops, Ankylosaurus">
4522 <AUTHOR name="Sereno" year="1986"/>
4523 <CSYNONYM name="Orbitoscuta"/>
4525 <TIME value="Barremian"/>
4526 <TIME value="Aptian"/>
4527 <PLACE name="Japan"/>
4530 <TIME value="Albian"/>
4531 <PLACE name="Utah"/>
4534 <REMAINS content="neck vertebra"/>
4535 <TIME value="Coniacian"/>
4536 <TIME value="Santonian"/>
4537 <PLACE name="Japan"/>
4540 <REMAINS content="teeth"/>
4541 <TIME value="Valanginian"/>
4542 <TIME value="Aptian"/>
4543 <PLACE name="Japan"/>
4545 <CGENUS name="Echinodon"/>
4546 <CGENUS name="Peishansaurus"/>
4547 <CGENUS name="Taveirosaurus"/>
4548 <CGENUS name="Thecospondylus" q="1"/>
4549 <CLINK name="Thyreophora"/>
4550 <CLADE name="Cerapoda" in="Triceratops, Iguanodon" silhouette="cerapoda">
4552 Cera<LOW>topsia and Ornitho</LOW>poda
4554 <CSYNONYM name="Neornithischia"/>
4555 <CGENUS incertae="1" name="Claorhynchus"/>
4556 <CGENUS incertae="1" name="Notoceratops"/>
4557 <CGENUS incertae="1" name="Tianchungosaurus" q="1"/>
4558 <CLINK name="Heterodontosauridae"/>
4559 <CLINK name="Ornithopoda"/>
4560 <CLADE name="Marginocephalia" in="Triceratops, Pachycephalosaurus">
4561 <AUTHOR name="Sereno" year="1986"/>
4565 <CGENUS name="Xuanhuasaurus" incertae="1"/>
4566 <CGENUS name="Stenopelix"/>
4567 <CLINK name="Pachycephalosauria"/>
4568 <CLINK name="Ceratopsia"/>
4575 <CLADOGRAM alternate="1">
4576 <CLADE name="Genasauria">
4577 <CLADE name="Thyreophora">
4578 <CGENUS name="Scutellosaurus"/>
4579 <CLADE name="Thyreophoroidea">
4580 <CGENUS name="Scelidosaurus"/>
4581 <CLADE name="Ankylosauria"/>
4585 <CLADE name="Stegosauria" comment="definition altered">
4586 <CGENUS name="Emausaurus"/>
4588 <CLADE name="Huayangosauridae"/>
4589 <CLADE name="Stegosauridae"/>
4592 <CLADE name="Cerapoda">
4593 <CLADE name="Ornithopoda"/>
4595 <CLADE name="Heterodontosauridae"/>
4596 <CLADE name="Marginocephalia"/>
4602 <CLADOGRAM alternate="1">
4603 <CLADE name="Genasauria" comment="definition altered">
4604 <CLADE name="Ornithopoda"/>
4605 <CLADE name="Orbitoscuta" in="Triceratops, Ankylosaurus">
4606 <CLADE name="Thyreophora"/>
4607 <CLADE name="Marginocephalia"/>
4611 <CLADOGRAM alternate="1">
4612 <CLADE name="Ornithischia">
4613 <CGENUS name="Pisanosaurus"/>
4615 <CLADE name="Genasauria"/>
4616 <CLADE name="Fabrosauridae">
4617 <AUTHOR name="Galton" year="1972"/>
4618 <AUTHOR type="sensu" name="Peng" year="1997"/>
4619 <CSYNONYM name="Lesothosauridae"/>
4620 <CGENUS name="Fabrosaurus"/>
4622 <CGENUS name="Agilisaurus"/>
4623 <CGENUS name="Gongbusaurus"/>
4629 <CLADOGRAM alternate="1">
4630 <CLADE name="Cerapoda">
4631 <CLADE name="Marginocephalia"/>
4632 <CLADE name="Ornithopoda">
4633 <CLADE name="Heterodontosauridae"/>
4634 <CLADE name="Euornithopoda"/>
4639 <P> <ILLO name="ornithischian_pelvis"/> Ornithischia includes the
4640 "bird-hipped" <LINK content="dinosaurs"/>, so called because the pubis
4641 seems to run backwards and parallel to the ischium as
4642 in <LINK content="birds"/> (in actuality, a process on the pubis grew
4643 backwards). Some dislike this name since certain
4644 <LINK content="saurischian dinosaurs"/> had more bird-like hips (especially
4645 birds themselves!). They prefer the name Predentata, which refers to the
4646 predentary bone in the front of the lower jaw. This bone is unique to
4647 these dinosaurs. </P>
4649 <P> Apart from certain <LINK content="theropods"/>, ornithischians were the only
4650 beaked dinosaurs. They were all herbivorous (save for a few possible
4651 omnivores, like <LINK content="heterodontosaurids"/>), and included a very wide
4652 variety of forms: <LINK content="armored tanks"/>,
4653 <LINK content="nimble runners & duck-bills"/>,
4654 <LINK content="lithe tuskers"/>, <LINK content="stone-headed chargers"/>, and
4655 <LINK content="the horned & frilled dinosaurs"/>. </P>
4657 <P header="Origin"> The earliest ornithischians were small, bipedal plant eaters, like
4658 <NOMEN name="Pisanosaurus"/> and <NOMEN name="Lesothosaurus"/>. Most later
4659 ornithischian lineages became quadrupedal as they evolved into bigger forms,
4660 although some, like the <LINK content="ornithopods"/> and
4661 <LINK content="pachycephalosaurs"/>, retained at least some degree of
4662 bipedality throughout. </P>
4666 <TAXON name="Ornithodira" nickname='"Bird Necks" - Dinosaurs & Pterosaurs'>
4667 <WORD key="1" content="lagosuchian, thecodontian, thecodont, origin, first, evolution, ancestors"/>
4668 <WORD essay="1" content="lagosuchian, lagosuchians"/>
4670 <CLADE name="Ornithodira" in="Neornithes, Pterodactylus, Lagosuchus, Herrerasaurus, Triceratops, Saltasaurus" silhouette="ornithosuchia">
4671 <AUTHOR name="Gauthier" year="1986"/>
4675 <CGENUS name="Avipes" incertae="1" q="1"/>
4676 <CGENUS name="Scleromochlus"/>
4677 <CLADE name="Pterosauromorpha" in="Pterodactylus" out="Neornithes" silhouette="pterosauromorpha">
4681 <CGENUS name="Sharovipteryx" q="1"/>
4682 <CLINK name="Pterosauria"/>
4684 <CLADE name="Dinosauromorpha" in="Neornithes" out="Pterodactylus">
4685 <AUTHOR name="Sereno" year="1991"/>
4689 <CGENUS name="Lagerpeton"/>
4690 <CLADE name="Dinosauriformes" in="Neornithes, Lagosuchus">
4694 <CGENUS name="Lagosuchus"/>
4695 <CGENUS name="Marasuchus"/>
4697 <CGENUS name="Pseudolagosuchus"/>
4698 <CLINK name="Dinosauria"/>
4704 <CLADOGRAM alternate="1">
4705 <REFER page="Archosauromorpha"/>
4708 <P header="Classification"> Ornithodira ("bird necks") is divided into two major sections.
4709 Dinosauromorpha includes <LINK content="dinosaurs"/> and their early
4710 ancestors, the "lagosuchians". These ancestors were very small, about
4711 1.5 to 3.5 feet long. They were probably carnivorous or insectivorous. </P>
4713 <P> The other group, Pterosauromorpha, includes <LINK content="Pterosauria"/>,
4714 the so-called "flying <LINK content="reptiles"/>" (although
4715 <LINK content="birds"/> are also considered reptiles under the cladistic
4716 system). There are two possible non-pterosaurian pterosauromorphs:
4717 <NOMEN name="Sharovipteryx"/>, an animal which may have
4718 glided on membranes supported by its hindlimbs; and
4719 <NOMEN name="Scleromochlus"/>, a small, poorly understood creature. </P>
4721 <P> Some do not consider pterosaurs to be close relatives of dinosaurs:
4722 <REFER page="Archosauromorpha"/><REFER page="http://home.stlnet.com/~azero/Pterosaur_Homepage.htm" title="The Pterosaur Home Page"/></P>
4724 <P header="Warm-Blooded, Cold-Blooded, or Both?"> All ornithodirans walked
4725 with a fully upright stance, like that of most <LINK content="mammals"/>.
4726 The group is named for the S-shaped neck found in most members. </P>
4728 <P> The only living ornithodirans, birds, are highly endothermic (or
4729 "warm-blooded"), but there is still debate as to the metabolic rate of
4730 extinct ornithodirans. The idea that they were endothermic has gained
4731 much acceptance in recent times, but some still maintain that they were
4732 ectothermic (or "cold-blooded"). Others think that they may have had
4733 intermediate metabolisms, or alternate types of physiology. But everyone
4734 agrees that the upright stance of ornithodirans indicates a high level
4735 of activity, regardless of metabolic rate. </P>
4737 <P> It has been suggested that the fur-like integument seen in some pterosaur
4738 fossils and the feathers seen in some dinosaurs (fossil and living) might be
4743 <TAXON name="Ornithomimosauria" nickname="Ostrich-Mimicking Speed Racers">
4744 <WORD key="1" content="ostrich, bird, mimic, fast, fastest, runner, cursorial, speed, velocity"/>
4745 <WORD essay="1" content="ostrich mimic, fast runners"/>
4747 <CLADE name="Ornithomimosauria" in="Ornithomimus, Pelecanimimus" silhouette="ornithomimosauria">
4748 <AUTHOR name="Barsbold" year="1976"/>
4749 <AUTHOR type="non" name="Sereno" year="1999"/>
4751 <NOMEN name="Ornithomimus"/> lizards
4753 <UNNAMED q="1" indet="1">
4754 <TIME value="Albian"/>
4755 <PLACE name="Australia"/>
4756 <REMAINS content="claw"/>
4757 <REMAINS q="1" content="pubis"/>
4759 <CGENUS name="Pelecanimimus"/>
4761 <CSYNONYM name="Ornithomimidae" sensu="Smith, Galton" year="1990"/>
4762 <CGENUS name="Harpymimus"/>
4763 <CLADE name="Ornithomimoidea">
4764 <AUTHOR type="implied" name="Marsh" year="1890"/>
4765 <AUTHOR type="non" name="Sereno" year="1999"/>
4766 <CGENUS name="Deinocheirus" incertae="1"/>
4767 <CGENUS name="Garudimimus" silhouette="garudimimus"/>
4768 <CLADE name="Ornithomimidae">
4769 <AUTHOR name="Marsh" year="1890"/>
4770 <AUTHOR type="non" name="Sereno" year="1999"/>
4772 <TIME value="Campanian"/>
4773 <PLACE name="Georgia"/>
4776 <TIME value="Campanian"/>
4777 <PLACE name="Montana"/>
4781 <PLACE name="China"/>
4782 <REMAINS content="12 skeletons (with gastroliths)"/>
4784 <CGENUS incertae="1" name="Sanchusaurus" q="1"/>
4785 <CGENUS name="Orcomimus" incertae="1"/>
4786 <CGENUS name="Archaeornithomimus"/>
4787 <CLADE name="Ornithomiminae">
4788 <AUTHOR type="implied" name="Marsh" year="1890"/>
4789 <CGENUS name="Gallimimus"/>
4790 <CGENUS name="Anserimimus"/>
4791 <CLADE name="Ornithomimini">
4792 <AUTHOR type="implied" name="Marsh" year="1890"/>
4793 <CGENUS name="Dromiceiomimus"/>
4794 <CGENUS name="Ornithomimus"/>
4795 <CGENUS name="Struthiomimus"/>
4803 <CLADOGRAM alternate="1">
4804 <REFER page="Coelurosauria"/>
4807 <P> These <LINK content="dinosaurs"/> are commonly known as the
4808 "ostrich mimics" or "ostrich dinosaurs" (although, technically,
4809 <LINK content="ostriches"/> <B>are</B> dinosaurs -- and if you think about
4810 it, isn't it ostriches who are ornithomimosaur mimics?). They were possibly
4811 the fastest of dinosaurs, with conjectured running speeds of 40-50 1.
4812 They all had very large eyes, like their possible relatives the
4813 <LINK content="troodontids"/>. </P>
4815 <P header="Physical Characteristics"> A peculiar feature of the ornithomimoids is the toothless, beaked mouth.
4816 This may indicate that they were one of the few groups of
4817 non-<LINK content="neornithean"/> <LINK content="theropods"/> to abandon a
4818 predatory lifestyle, possibly assuming an herbivorous or omnivorous mode of
4819 life similar to that of modern-day ostriches. Early ornithomimosaurs such as
4820 <NOMEN name="Pelecanimimus"/> and <NOMEN name="Harpymimus"/> still had teeth,
4821 although they were quite small. </P>
4823 <P> Ornithomimoids were all fairly similar. They had lost the first, inner
4824 toe, a dewclaw in most theropods. The ornithomimids are especially difficult
4825 to distinguish from each other, and for this reason some feel that they
4826 should all be lumped into one genus, <NOMEN name="Ornithomimus"/>. </P>
4828 <P header="Size"> Ornithomimosaurs were fairly similar in size, from the most primitive ones
4829 at 2 meters long to the advanced ones at 3.5-4m. The exception is the giant
4830 ornithomimoid <NOMEN name="Deinocheirus"/> </P>
4834 <TAXON name="Ornithopoda" nickname="From Dinosaurian Gazelles to Bulky Duck-Bills">
4835 <WORD key="1" content="hypsilophodontian"/>
4836 <WORD essay="1" content="nimble runners & duck-bills"/>
4838 <CLADE name="Ornithopoda" in="Iguanodon" out="Triceratops" silhouette="ornithopoda">
4842 <UNNAMED indet="1" comment="large">
4843 <REMAINS content="femur"/>
4844 <PLACE name="Australia"/>
4847 <REMAINS content="teeth"/>
4848 <TIME value="Valanginian"/>
4849 <PLACE name="Japan"/>
4852 <PLACE name="Texas"/>
4854 <UNNAMED comment="with nests">
4855 <TIME value="Aptian"/>
4856 <TIME value="Albian"/>
4857 <PLACE name="Texas"/>
4860 <REMAINS content="partial skeleton"/>
4862 <PLACE name="Spain"/>
4864 <UNNAMED content="small">
4865 <PLACE name="Japan"/>
4867 <CGENUS incertae="1" name="Anoplosaurus tanyspondylus"/>
4868 <CGENUS incertae="1" name="Atlascopcosaurus"/>
4869 <CGENUS incertae="1" name="Fulgurotherium"/>
4870 <CGENUS incertae="1" name="Leaellynasaura"/>
4871 <CGENUS incertae="1" name="Nanosaurus"/>
4872 <CGENUS incertae="1" name="Notohypsilophodon"/>
4873 <CGENUS incertae="1" name="Phyllodon"/>
4874 <CGENUS incertae="1" name="Qantassaurus"/>
4875 <CGENUS incertae="1" name="Siluosaurus"/>
4876 <CGENUS incertae="1" name="Tichosteus" q="1"/>
4877 <CGENUS incertae="1" name="Yandusaurus"/>
4878 <CGENUS name="Bugenasaura"/>
4879 <CGENUS name="Thescelosaurus"/>
4881 <CLADE name="Zephyrosauridae">
4882 <CGENUS name="Orodromeus"/>
4883 <CGENUS name="Zephyrosaurus"/>
4885 <CLADE name="Othnieliidae">
4886 <CGENUS name="Yandusaurus multidens"/>
4887 <CLADE name="Othnieliinae">
4888 <CGENUS name="Drinker"/>
4889 <CGENUS name="Othnielia"/>
4892 <CLADE name="Euornithopoda" in="Iguanodon, Hypsilophodon">
4893 <AUTHOR name="Sereno" year="1986"/>
4897 <CGENUS name="Parksosaurus"/>
4898 <CLADE name="Hypsilophodontia" in="Hypsilophodon" out="Iguanodon">
4899 <CSYNONYM name="Hypsilophodontidae" sensu="Sues" year="1997"/>
4901 <NOMEN name="Hypsilophodon"/>'s <LOW>taxon</LOW>
4903 <CGENUS name="Hypsilophodon"/>
4905 <CLINK name="Iguanodontia"/>
4910 <CLADOGRAM alternate="1">
4911 <CLADE name="Ornithopoda">
4912 <CLINK name="Heterodontosauridae"/>
4913 <CLADE name="Euornithopoda">
4914 <CLADE name="Iguanodontia"/>
4915 <CLADE name="Hypsilophodontia">
4916 <CGENUS name="Bugenasaura"/>
4917 <CGENUS name="Thescelosaurus"/>
4918 <CLADE name="Hypsilophodontoidea">
4919 <CLADE name="Hypsilophodontidae"/>
4920 <CLADE name="Othnieliidae"/>
4921 <CLADE name="Zephyrosauridae"/>
4928 <P header="History of Classification"> This group has at various times included nearly all bipedal
4929 <LINK content="ornithischians"/>. By now many forms once included here have
4930 been recognized as primitive members of other largely quadrupedal groups
4931 (<NOMEN name="Scutellosaurus"/>, <NOMEN name="Psittacosaurus"/>),
4932 creatures too primitive to belong to any major ornithischian clade
4933 (<NOMEN name="Pisanosaurus"/>, <NOMEN name="Lesothosaurus"/>),
4934 or members of their own group (<LINK content="pachycephalosaurs"/>).
4935 Ornithopoda still includes "hypsilophodonts" and
4936 <LINK content="iguanodonts"/> (including <LINK content="hadrosaurids"/>,
4937 or duck-billed dinosaurs), and possibly <LINK content="heterodontosaurids"/>
4940 <P> It was once thought that the animals listed on this page formed a clade:
4941 Hypsilophodontia, sister clade of <LINK content="Iguanodontia"/>. But newer
4942 studies indicate that this group was paraphyletic. The only definite
4943 hypsilophodont is <NOMEN name="Hypsilophodon"/> itself. </P>
4945 <P header="Niche"> The animals on this page were small or tiny bipedal runners which may
4946 have lived lifestyles similar to those of such modern-day
4947 <LINK content="mammals"/> as deer, gazelles, and kangaroos. From creatures
4948 such as these came the larger, semi-quadrupedal iguanodonts. </P>
4952 <TAXON name="Ornithurae" nickname="Advanced Birds" silhouette="ambiortimorphae">
4953 <WORD key="1" content="bird, toothed, teeth, origin, evolution, classification, cladogram"/>
4954 <WORD essay="1" content="ichthyornithid, ornithuran bird"/>
4956 <CLADE name="Ornithurae" in="Neornithes, Hesperornis" silhouette="pygostylia">
4960 <CLADE name="Patagopterygiformes">
4961 <CGENUS name="Patagopteryx" silhouette="pygostylia-flightless"/>
4962 <CGENUS q="1" name="Gargantuavis" silhouette="pygostylia-flightless"/>
4963 <CGENUS q="1" name="Kuszholia" silhouette="pygostylia-flightless"/>
4965 <CLINK name="Hesperornithiformes"/>
4966 <CLADE name="Carinatae" in="Neornithes, Ichthyornis">
4967 <CLADE name="Ambiortimorphae" in="Ambiortus" out="Neornithes" silhouette="ambiortimorphae">
4969 <NOMEN name="Ambiortus"/> forms
4971 <CLADE name="Ambiortiformes">
4972 <CGENUS name="Ambiortus"/>
4974 <CLADE name="Chaoyangiiformes" q="1">
4975 <CLADE name="Chaoyangiidae">
4976 <CGENUS name="Chaoyangia"/>
4978 <CLADE name="Songlingornithidae">
4979 <CGENUS name="Songlingornis"/>
4982 <CLADE name="Ichthyornithiformes">
4983 <CSYNONYM name="Apatornithiformes" q="1"/>
4985 <NOMEN name="Ichthyornis"/> forms
4988 <PLACE name="N. America"/>
4990 <CGENUS name="Apatornis" q="1"/>
4991 <CGENUS name="Ichthyornis"/>
4994 <CLINK name="Neornithes"/>
4999 <P> Ornithurans include modern birds (<LINK content="neornitheans"/>) and
5000 their relatives. Except for neornitheans, ornithurans retained small
5001 teeth in their jaws, except at the front of the upper jaw (premaxilla). </P>
5003 <P header="Varieties"> Four main types are known: the flightless patagopterygiforms,
5004 the aquatic <LINK content="hesperornithiforms"/>, the seaside-dwelling
5005 ambiortimorphs, and the extremely diverse neornitheans. All lived in the
5006 <LINK content="Cretaceous Period"/>, and all except neornitheans died out at the
5007 end of the Cretaceous. </P>
5011 <TAXON name="Oviraptorosauria" nickname="Toothless Weirdos & Little Sprinters" silhouette="oviraptoridae-crested">
5012 <WORD key="1" content="egg, eggs, nest, nests"/>
5013 <WORD essay="1" content="toothless weirdos"/>
5015 <CLADE name="Oviraptorosauria" in="Oviraptor, Chirostenotes" silhouette="oviraptorosauria">
5016 <AUTHOR name="Barsbold" year="1976"/>
5017 <AUTHOR type="sensu" name="Padian, Hutchinson, Holtz" year="1998"/>
5019 <NOMEN name="Oviraptor"/> lizards
5021 <CSYNONYM name="Caenagnathidae" sensu="Paul" year="1988"/>
5022 <CSYNONYM name="Caenagnathoidea"/>
5023 <CSYNONYM name="Oviraptoroidea"/>
5024 <CGENUS name="Nomingia" incertae="1"/>
5025 <CLADE name="Caenagnathidae" in="Chirostenotes" out="Oviraptor">
5026 <UNNAMED comment="large">
5027 <TIME section="late" value="Maastrichtian"/>
5028 <PLACE name="S. Dakota"/>
5030 <CSYNONYM name="Elmisauridae"/>
5031 <CGENUS name="Caenagnathasia"/>
5032 <CLADE name="Caenagnathinae">
5033 <CSYNONYM name="Elmisaurinae"/>
5034 <CGENUS name="Chirostenotes"/>
5035 <CGENUS name="Elmisaurus"/>
5038 <CLADE name="Oviraptoridae" in="Oviraptor" out="Chirostenotes">
5039 <UNNAMED cf="Oviraptor">
5040 <REMAINS content="postcranium with nest of eggs"/>
5041 <PLACE name="Mongolia"/>
5042 <TIME value="Campanian"/>
5043 <TIME value="Maastrichtian"/>
5045 <UNNAMED comment="large">
5046 <PLACE name="Mongolia"/>
5048 <CGENUS name="Conchoraptor"/>
5049 <CGENUS name="Ingenia"/>
5050 <CGENUS name="Oviraptor" silhouette="oviraptoridae-crested"/>
5051 <CGENUS name="Rinchenia" silhouette="oviraptoridae-crested"/>
5056 <P header="Classification and Characteristics"> This group includes the oviraptorids and the caenagnathids. The latter
5057 are a somewhat poorly known group, known mainly by hands and feet, which
5058 are fairly <LINK content="bird"/>-like. </P>
5060 <P> Oviraptorids were a very peculiar group of <LINK content="theropods"/>.
5061 Their mouths were entirely toothless, forming beaks. They were sometimes
5062 classified with the <LINK content="ornithomimids"/>, another group of
5063 toothless theropods. However, they lack the arctometatarsalian foot of
5064 the ornithomimids and other <LINK content="arctometatarsalian"/>
5067 <P header="A Devoted Mother"> One oviraptorid specimen was found huddled atop a nest of its own eggs,
5068 its wing-like arms spread over them. Apparently it was protecting its brood
5069 when a sand avalanche buried and killed it. (The head of the
5070 specimen is missing, so it is not certain which type of oviraptorid it is,
5071 although it may well be <NOMEN name="Oviraptor"/>.) </P>
5073 <P header="The End"> It is not certain whether oviraptorosaurs made it to the very end of
5074 the <LINK content="Mesozoic Era"/>. There is no evidence of them from very
5075 late <LINK content="Maastrichtian"/> sediments, so they may have died out
5076 right before the K/T Extinction. But some dinosaur groups are only known to
5077 have died out in the K/T Extinction because their teeth have been found from
5078 that time. Since oviraptorosaurs had no teeth, and teeth preserve better than
5079 other remains, they may have made it to the end but not left any evidence
5080 that we have yet found. </P>
5084 <TAXON name="Pachycephalosauria" nickname="Bone-Heads">
5085 <WORD key="1" content="bone, butt, bone-headed, butt-headed, head, heads, headed, ram, ramming"/>
5086 <WORD essay="1" content="stone-headed chargers"/>
5088 <CLADE name="Pachycephalosauria" in="Pachycephalosaurus" out="Triceratops" silhouette="pachycephalosauria">
5090 <NOMEN name="Pachycephalosaurus"/>' <LOW>taxon</LOW>
5093 <PLACE name="India"/>
5095 <CGENUS name="Yaverlandia" incertae="1"/>
5096 <CGENUS name="Wannanosaurus"/>
5097 <CLADE name="Goyocephalia" in="Goyocephale, Pachycephalosaurus">
5099 <NOMEN name="Goyocephale"/>'s <LOW>taxon</LOW>
5101 <CGENUS name="Goyocephale"/>
5102 <CGENUS name="Micropachycephalosaurus"/>
5103 <CLADE name="Homalocephaloidea" in="Homalocephale, Pachycephalosaurus">
5104 <CGENUS name="Homalocephale"/>
5105 <CGENUS name="Ornatotholus" q="1"/>
5106 <CLINK name="Pachycephalosauridae"/>
5112 <P> This was an odd group of <LINK content="ornithischians"/>, characterized by an
5113 extremely thick skull roof, often lined with small bumps and spikes. The
5114 most commonly accepted explanation for these thick "bone-heads" is that
5115 they were used to butt heads in mating displays similar to those of
5118 <P header="History of Classification"> Pachycephalosaurs were once classified as <LINK content="ornithopods"/>,
5119 mainly because of their bipedal stance. But they seem to be more closely
5120 related to the <LINK content="ceratopsians"/>, due to similarities such
5121 as a ridge along the back of the skull, which evolved into a frill among
5122 the ceratopsians. </P>
5124 <P> The genera listed here were the "flat-headed" pachycephalosaurs. They
5125 were sometimes grouped into the family Homalocephalidae, although this is
5126 probably paraphyletic. </P>
5128 <P header="Location"> Pachycephalosaurs, known only from the northern hemisphere
5129 (with few possible exceptions), are fairly
5130 rare, leading some to theorize that they may have inhabited environments
5131 that were not conducive to fossilization, such as mountains. </P>
5135 <TAXON name="Pachycephalosauridae" nickname="Dome-Heads">
5136 <WORD key="1" content="bone, butt, dome, dome-headed, head, heads, headed, ram, sheep"/>
5138 <CLADE name="Pachycephalosauridae" silhouette="pachycephalosauridae">
5139 <CGENUS name="Stegoceras"/>
5140 <CLADE name="Pachycephalosaurinae">
5141 <CLADE content="Asian forms">
5142 <CGENUS name="Tylocephale"/>
5143 <CGENUS name="Prenocephale"/>
5145 <CLADE name="Pachycephalosaurini" content="N. American forms">
5146 <UNNAMED comment="high-domed">
5147 <TIME section="middle-late" value="Campanian"/>
5148 <PLACE name="Alberta"/>
5150 <CGENUS name="Gravitholus" q="1"/>
5151 <CGENUS name="Microcephale" q="1"/>
5152 <CGENUS name="Pachycephalosaurus"/>
5153 <CGENUS name="Stygimoloch" silhouette="stygimoloch"/>
5159 <P> Pachycephalosaurids were the "dome-headed" pachycephalosaurs. Their skull
5160 roofs were immensely thickened to create a large dome of solid bone on the
5161 top of their skulls. The dome was adorned by bumps and spikes, which grew
5162 quite long in <NOMEN name="Stygimoloch"/>. The spine was strengthened,
5163 possibly for head-on butting. </P>
5165 <P> <NOMEN name="Pachycephalosaurus"/>, at around 25 feet in length, was
5166 by far the giant of the group. Most other species were less than 10 feet
5167 long. <NOMEN name="Microcephale"/> was one of the smallest
5168 non-<LINK content="avian"/> dinosaurs. </P>
5172 <TAXON name="Pterodactyloidea" nickname='"Pterodactyls" - Advanced Fliers'>
5173 <WORD key="1" content="pterodactyl, ptero, pterodactyls, flying, flight, soaring, flew, wing"/>
5175 <CLADE name="Pterodactyloidea" silhouette="pterodactyloidea">
5176 <UNNAMED q="1" comment="large">
5177 <TIME value="Kimmeridgian"/>
5178 <REMAINS content="right manual phalanx II"/>
5179 <!--WINGSPAN value="3.5"/-->
5180 <!--WINGSPAN value="5"/-->
5182 <CGENUS incertae="1" name="Dermodactylus"/>
5183 <CGENUS incertae="1" name="Eosipterus"/>
5184 <CGENUS incertae="1" name="Herbstosaurus"/>
5185 <CGENUS incertae="1" name="Kepodactylus"/>
5186 <CGENUS incertae="1" name="Mesadactylus"/>
5187 <CGENUS incertae="1" name="Wyomingopteryx"/>
5189 <CGENUS name="Nyctosaurus" silhouette="pterodactyloidea-crested"/>
5190 <CLADE name="Ornithocheiroidea">
5191 <CLADE name="Ornithocheiridae" silhouette="pterodactyloidea-curved">
5193 <TIME value="Cenomanian"/>
5194 <PLACE name="Morocco"/>
5195 <REMAINS content="teeth"/>
5198 <TIME value="Albian"/>
5199 <PLACE name="Australia"/>
5200 <REMAINS content="shoulder girdle, vertebra, mandible section"/>
5202 <CGENUS name="Araripedactylus" q="1"/>
5203 <CGENUS name="Araripesaurus" q="1"/>
5204 <CGENUS name="Brasileodactylus"/>
5205 <CGENUS name="Ornithocheirus"/>
5206 <CGENUS name="Santanadactylus"/>
5208 <CLADE name="Pteranodontoidea" silhouette="pteranodontoidea">
5210 <TIME value="Cenomanian"/>
5211 <PLACE name="Morocco"/>
5212 <REMAINS content="jaw fragments"/>
5215 <TIME value="Albian"/>
5216 <PLACE name="Australia"/>
5217 <REMAINS content="partial pelvis, sacral centra, sacral rib"/>
5218 <REMAINS q="1" content="toothed jaw fragment"/>
5220 <CGENUS name="Bogolubovia" q="1"/>
5221 <CGENUS name="Ornithostoma"/>
5222 <CGENUS name="Ornithodesmus latidens"/>
5223 <CGENUS name="Pteranodon" silhouette="pteranodon"/>
5224 <CLADE name="Anhangueridae" silhouette="anhangueridae">
5227 <PLACE name="Australia"/>
5228 <REMAINS content="front of upper jaw without tip"/>
5230 <CGENUS q="1" name="Cearadactylus"/>
5231 <CGENUS name="Coloborhynchus clavirostris"/>
5232 <CGENUS name="Criorhynchus"/>
5233 <CGENUS name="Siroccopteryx"/>
5234 <CGENUS name="Tropeognathus"/>
5235 <CLADE name="Anhanguerinae">
5236 <CGENUS name="Anhanguera" silhouette="anhanguera"/>
5237 <CGENUS name="Arthurdactylus" silhouette="pterodactyloidea"/>
5245 <CGENUS name="Cycnorhamphus" silhouette="pterodactyloidea-crested"/>
5246 <CGENUS name="Normannognathus" q="1"/>
5247 <CLADE name="Pterodactylidae">
5248 <CSYNONYM name="Germanodactylidae"/>
5249 <CGENUS name="Germanodactylus" q="1"/>
5250 <CGENUS name="Pterodactylus"/>
5252 <CLADE name="Ctenochasmatidae" silhouette="ctenochasmatidae">
5253 <CGENUS name="Ctenochasma" silhouette="pterodactyloidea-curved"/>
5254 <CGENUS name="Huanhepterus"/>
5255 <CGENUS name="Pterodaustro" silhouette="pterodaustro"/>
5256 <CLADE name="Gnathosaurinae" status="informal" silhouette="gnathosaurinae">
5257 <CGENUS name="Gnathosaurus"/>
5258 <CGENUS name="Plataleorhynchus"/>
5263 <CLADE name="Dsungaripteridae" silhouette="dsungaripteridae">
5264 <CGENUS name="Dsungaripterus"/>
5265 <CGENUS name="Noripterus"/>
5266 <CGENUS name="Phobetor"/>
5267 <CGENUS name="Puntanipterus"/>
5269 <CLADE name="Azhdarchoidea" silhouette="azhdarchoidea">
5271 <TIME value="Cenomanian"/>
5272 <PLACE name="Morocco"/>
5273 <REMAINS content="jaw fragments"/>
5275 <CGENUS name="Tapejara" silhouette="tapejara"/>
5277 <CGENUS name="Tupuxuara" silhouette="tupuxuara"/>
5278 <CLADE name="Azhdarchidae">
5280 <TIME value="Cenomanian"/>
5281 <PLACE name="Morocco"/>
5282 <REMAINS content="jaw fragments"/>
5284 <UNNAMED comment="Solana giant">
5285 <PLACE name="Spain"/>
5288 <PLACE name="Brazil"/>
5289 <TIME value="Albian"/>
5290 <REMAINS content="specimen with skin impressions"/>
5293 <PLACE name="Australia"/>
5294 <TIME value="Maastrichtian"/>
5295 <REMAINS content="proximal end of ulna"/>
5297 <CGENUS name="Arambourgiania"/>
5298 <CGENUS name="Azhdarcho"/>
5299 <CGENUS name="Bennettazhia" q="1"/>
5300 <CGENUS name="Diopocephalus" silhouette="azhdarchidae-small"/>
5301 <CGENUS name="Doratorhynchus" q="1"/>
5302 <CGENUS name="Montanazhdarcho"/>
5303 <CGENUS name="Quetzalcoatlus" silhouette="quetzalcoatlus"/>
5304 <CGENUS name="Zhejiangopterus"/>
5312 <CLADOGRAM alternate="1">
5313 <CLADE name="Pterodactyloidea">
5314 <CLADE name="Scalmognatha" status="informal">
5315 <CGENUS name="Germanodactylus"/>
5317 <CGENUS name="Pteranodon"/>
5319 <CGENUS name="Nyctosaurus"/>
5320 <CLADE name="Dsungaripteridae"/>
5321 <CLADE name="Tapejaridae">
5322 <CGENUS name="Tapejara"/>
5323 <CGENUS name="Tupuxuara"/>
5328 <CLADE name="Euthygnatha" status="informal">
5329 <CGENUS name="Germanodactylus rhamphastinus"/>
5333 <CGENUS name="Cycnorhamphus"/>
5334 <CGENUS name="Ornithodesmus latidens"/>
5336 <CLADE name="Ornithocheiroidea">
5337 <CGENUS name="Ornithocheirus"/>
5338 <CLADE name="Anhangueridae"/>
5341 <CGENUS name="Pterodactylus"/>
5343 <CGENUS name="Pterodaustro"/>
5345 <CLADE name="Ctenochasmatidae">
5346 <CGENUS name="Ctenochasma"/>
5347 <CGENUS name="Gnathosaurus"/>
5349 <CLADE name="Tanydiroptera" status="informal">
5350 <CGENUS name="Diopocephalus"/>
5351 <CGENUS name="Doratorhynchus"/>
5352 <CGENUS name="Huanhepterus"/>
5353 <CLADE name="Azhdarchidae"/>
5362 <P> Pterodactyloids included the largest flying animals of all time. Giants
5363 like <NOMEN name="Quetzalcoatlus"/> could grow to have wingspans over 30
5364 feet, possibly weighing over 500 pounds. </P>
5366 <P header="Rise and Fall"> These short-tailed <LINK
5367 content="pterosaurs"/> came in a wide
5368 variety of forms, from the forceps-beaked <NOMEN name="Dsungaripterus"/> to
5369 the sieve-toothed <NOMEN name="Pterodaustro"/> to the toothless
5370 <NOMEN name="Pteranodon"/>. Several had enormous crests atop their heads. </P>
5372 <P> Pterodactyloid diversity declined throughout the
5373 <LINK content="Late Cretaceous"/>. By the end there were only a few giant
5374 forms, the smaller niches having all been taken over by
5375 <LINK content="birds"/>. This last remnant went extinct at the end of the
5376 <LINK content="Cretaceous"/>, as did all <LINK content="ornithodirans"/>
5377 save for <LINK content="neornithean birds"/>. </P>
5381 <TAXON name="Pterosauria" nickname="Flying Reptiles">
5382 <WORD key="1" content="pterodactyl, flying, reptile, wing, flight"/>
5384 <CLADE name="Pterosauria" in="Pterodactylus, Preondactylus" silhouette="pterosauria">
5385 <AUTHOR type="sensu" name="Sereno" year="1991"/>
5386 <MEANING>winged lizards</MEANING>
5387 <CSYNONYM name="Ornithosauria"/>
5388 <UNNAMED comment="crested, toothed"/>
5390 <TIME value="Barremian"/>
5391 <PLACE name="Australia"/>
5394 <TIME value="Aptian"/>
5395 <PLACE name="Australia"/>
5398 <TIME value="Berriasian"/>
5399 <PLACE name="Africa"/>
5401 <CGENUS incertae="1" name="Comodactylus"/>
5402 <CGENUS incertae="1" name="Laopteryx"/>
5403 <CGENUS incertae="1" name="Rhamphinion"/>
5404 <CGENUS name="Preondactylus"/>
5406 <CLADE name="Anurognathidae" silhouette="anurognathidae">
5407 <CGENUS q="1" name="Dendrorhynchoides"/>
5408 <CGENUS name="Anurognathus" silhouette="anurognathus"/>
5409 <CGENUS name="Batrachognathus"/>
5412 <CGENUS name="Sordes"/>
5414 <CGENUS name="Scaphognathus"/>
5415 <CGENUS name="Odontorhynchus" q="1"/>
5417 <CGENUS name="Dorygnathus" silhouette="dorygnathus"/>
5419 <CLADE name="Dimorphodontidae" silhouette="dimorphodontidae">
5420 <CGENUS name="Dimorphodon" silhouette="pterosauria"/>
5421 <CGENUS name="Nesodactylus" q="1"/>
5422 <CGENUS name="Peteinosaurus"/>
5425 <CLADE name="Campylognathoididae">
5426 <CGENUS name="Campylognathoides"/>
5427 <CGENUS name="Eudimorphodon"/>
5430 <CLADE name="Rhamphorhynchidae" silhouette="rhamphorhynchidae">
5431 <CGENUS name="Rhamphocephalus"/>
5432 <CGENUS name="Rhamphorhynchus"/>
5435 <CGENUS name="Angustinaripterus"/>
5436 <CGENUS name="Parapsicephalus"/>
5437 <CLINK name="Pterodactyloidea"/>
5448 <CLADOGRAM alternate="1">
5449 <CLADE name="Pterosauria">
5450 <CGENUS name="Preondactylus"/>
5452 <CLADE name="Dimorphodontidae">
5453 <CGENUS name="Peteinosaurus"/>
5455 <CGENUS name="Dimorphodon"/>
5457 <CGENUS name="Nesodactylus"/>
5458 <CLADE name="Anurognathinae">
5459 <CGENUS name="Anurognathus"/>
5460 <CGENUS name="Batrachognathus"/>
5465 <CLADE name="Tipidactyla" status="informal">
5466 <CLADE name="Rhamphorhynchidae">
5467 <CGENUS name="Eudimorphodon"/>
5469 <CGENUS name="Campylognathoides"/>
5470 <CLADE name="Rhamphorhynchinae">
5471 <CGENUS name="Dorygnathus"/>
5472 <CGENUS name="Rhamphorhynchus"/>
5477 <CGENUS name="Sordes"/>
5479 <CGENUS name="Scaphognathus"/>
5481 <CGENUS name="Parapsicephalus"/>
5483 <CGENUS name="Angustinaripterus"/>
5484 <CLADE name="Pterodactyloidea"/>
5494 <P header="Fliers Unlike Any Other"> Although they were the only other flying <LINK content="archosaurs"/>,
5495 pterosaurs were not closely related to <LINK content="birds"/>. Their
5496 wings had a very different structure. Birds support their wings with their
5497 second finger (or possibly third, if the frame shift hypothesis is true),
5498 while pterosaurs used the fourth. Additionally, pterosaurian
5499 wings were largely made up of skin membranes strengthened by fibers, while
5500 avian wings consist mainly of feathers. </P>
5502 <P header="Origins and Evolution"> Pterosaurs originated at about the
5504 <LINK content="dinosaurs"/>. They began as small, long-tailed forms,
5505 sometimes called "rhamphorhynchoids". From these came larger,
5506 short-tailed forms, which make up the group
5507 <LINK content="Pterodactyloidea"/>. </P>
5509 <P> There is a recent theory that pterosaurs were not archosaurs, but
5510 derived from some type of basal <LINK content="archosauromorph"/>.
5512 <REFER page="http://home.stlnet.com/~azero/Pterosaur_Homepage.htm"
5513 title="The Pterosaur Home Page"/> </P>
5515 <P header="Integument"> Pterosaurs were unique among <LINK content="reptiles"/> in that at least some
5516 of them were covered with hair, similar but not homologous to
5517 <LINK content="mammalian"/> hair. Although in some cases fibers in the wing
5518 membrane have been mistaken for hair, some fossils such as those of
5519 <NOMEN name="Sordes pilosus"/> ("hairy demon") do show hair on the head,
5520 neck, and torso, much like modern-day bats. </P>
5524 <TAXON name="Sauropoda" nickname="Behemoths of the Land">
5525 <WORD key="1" content="brontosaur, cetiosaur, big, huge, large, humongous, giant, enormous, gigantic, biggest, largest, hugest, heaviest, heavy, bulky, bulkiest, earth, shaking, club, tail, tailed, neck, long, longest, defense, weapon"/>
5526 <WORD essay="1" content="cetiosaur"/>
5528 <CLADE name="Sauropoda" in="Saltasaurus" out="Plateosaurus" silhouette="sauropoda">
5529 <AUTHOR name="Marsh" year="1878"/>
5530 <AUTHOR type="sensu" name="Wilson, Sereno"/>
5531 <MEANING>lizard feet</MEANING>
5532 <CSYNONYM name="Opisthocoelia" sensu="Riggs">
5533 <AUTHOR name="Owen" year="1860"/>
5536 <TIME value="Hettangian"/>
5537 <TIME value="Sinemurian"/>
5538 <PLACE name="China"/>
5539 <REMAINS content="left maxilla"/>
5542 <TIME section="middle" value="Barremian"/>
5543 <PLACE name="China"/>
5546 <TIME section="late" value="Barremian"/>
5547 <PLACE name="China"/>
5550 <TIME section="late" value="Aptian"/>
5551 <PLACE name="China"/>
5554 <TIME value="Campanian"/>
5555 <TIME value="Maastrichtian"/>
5556 <PLACE name="New Zealand"/>
5559 <TIME value="Albian"/>
5560 <PLACE name="Australia"/>
5563 <TIME value="Bajocian"/>
5564 <PLACE name="Australia"/>
5567 <TIME value="Aptian"/>
5568 <TIME value="Albian"/>
5569 <PLACE name="Japan"/>
5572 <TIME value="Albian"/>
5573 <PLACE name="Utah"/>
5576 <TIME value="Albian"/>
5577 <TIME value="Cenomanian" section="early"/>
5578 <PLACE name="Africa"/>
5582 <PLACE name="Yemen"/>
5585 <REMAINS content="teeth"/>
5586 <TIME value="Barremian"/>
5587 <TIME value="Aptian"/>
5588 <PLACE name="Japan"/>
5591 <REMAINS content="tooth"/>
5592 <TIME value="K" q="1"/>
5593 <PLACE name="Japan"/>
5596 <REMAINS content="tooth"/>
5597 <TIME value="Coniacian"/>
5598 <TIME value="Santonian"/>
5599 <PLACE name="Japan"/>
5601 <UNNAMED comment="large">
5602 <TIME value="Barremian"/>
5603 <PLACE name="China"/>
5605 <UNNAMED comment="small">
5606 <PLACE name="England"/>
5610 <PLACE name="Portugal"/>
5612 <CGENUS incertae="1" name="Asiatosaurus"/>
5613 <CGENUS incertae="1" name="Cardiodon"/>
5614 <CGENUS incertae="1" name="Kunmingosaurus"/>
5615 <CGENUS incertae="1" name="Moshisaurus"/>
5616 <CGENUS incertae="1" name="Pleurocoelus altus"/>
5617 <CGENUS incertae="1" name="Qinlingosaurus"/>
5618 <CGENUS name="Titanosaurus falloti" incertae="1"/>
5619 <CGENUS incertae="1" name="Titanosaurus rahioliensis"/>
5620 <CGENUS incertae="1" name="Ultrasaurus"/>
5621 <CLADE name="Tendaguriidae" incertae="1">
5622 <AUTHOR name="Bonaparte, Heinrich, Wild" year="2000"/>
5623 <CGENUS name="Tendaguria"/>
5625 <CGENUS name="Isanosaurus"/>
5626 <CGENUS name="Kotasaurus" q="1"/>
5628 <CGENUS name="Vulcanodon"/>
5629 <CLADE in="Saltasaurus" out="Vulcanodon">
5630 <CSYNONYM name="Eusauropoda" sensu="Wilson, Sereno"/>
5631 <CGENUS name="Datousaurus" incertae="1"/>
5632 <CGENUS name="Shunosaurus" incertae="1" silhouette="shunosaurus"/>
5633 <CGENUS name="Barapasaurus"/>
5634 <CGENUS name="Ohmdenosaurus" q="1"/>
5635 <CGENUS name="Zizhongosaurus" q="1"/>
5636 <CLADE name="Eusauropoda" in="Saltasaurus" out="Barapasaurus, Ohmdenosaurus, Vulcanodon, Zizhongosaurus">
5637 <AUTHOR name="Upchurch"/>
5638 <MEANING>true sauropods</MEANING>
5639 <CGENUS incertae="1" name="Chuanjiesaurus"/>
5640 <CGENUS incertae="1" name="Dachongosaurus"/>
5641 <CGENUS name="Euhelopus" incertae="1" silhouette="euhelopodinae"/>
5642 <CGENUS incertae="1" name="Hudiesaurus"/>
5643 <CGENUS incertae="1" name="Klamelisaurus"/>
5644 <CGENUS incertae="1" name="Lancanjiangosaurus"/>
5645 <CGENUS name="Lapparentosaurus" incertae="1"/>
5646 <CGENUS incertae="1" name="Morosaurus agilis"/>
5647 <CGENUS name="Mamenchisaurus" incertae="1" silhouette="euhelopodinae"/>
5648 <CGENUS incertae="1" name="Nurosaurus"/>
5649 <CGENUS incertae="1" name="Omeisaurus" silhouette="euhelopodinae"/>
5650 <CGENUS incertae="1" name="Oshanosaurus" q="1"/>
5651 <CGENUS incertae="1" name="Protognathosaurus"/>
5652 <CGENUS incertae="1" name="Rhoetosaurus"/>
5653 <CGENUS incertae="1" name="Tehuelchesaurus" silhouette="euhelopodinae"/>
5654 <CGENUS incertae="1" name="Tienshanosaurus"/>
5655 <CGENUS name="Amygdalodon"/>
5657 <CGENUS name="Volkheimeria" q="1"/>
5659 <CGENUS name="Patagosaurus" q="1"/>
5661 <CGENUS name="Cetiosaurus" q="1"/>
5663 <CGENUS name="Rebbachisaurus tasmenensis" incertae="1" q="1"/>
5664 <CGENUS name="Jobaria"/>
5665 <CLADE name="Neosauropoda" in="Saltasaurus, Diplodocus">
5669 <CGENUS name="Cetiosauriscus" incertae="1"/>
5670 <CGENUS name="Haplocanthosaurus"/>
5671 <CLADE name="Agustiniidae" incertae="1" silhouette="agustiniidae">
5672 <CSYNONYM name="Agustinidae"/>
5673 <CGENUS name="Agustinia"/>
5675 <CLINK name="Diplodocimorpha"/>
5676 <CLINK name="Macronaria"/>
5687 <CLADOGRAM alternate="1">
5688 <CLADE name="Sauropoda">
5689 <CLADE name="Vulcanodontidae">
5690 <CSYNONYM name="Barapasauridae"/>
5691 <CGENUS name="Barapasaurus"/>
5692 <CGENUS name="Ohmdenosaurus"/>
5693 <CGENUS name="Vulcanodon"/>
5694 <CGENUS name="Zizhongosaurus"/>
5696 <CLADE name="Eusauropoda">
5698 <CGENUS name="Cetiosaurus"/>
5699 <CLADE name="Neosauropoda"/>
5701 <CLADE name="Euhelopodidae">
5702 <CSYNONYM name="Mamenchisauridae"/>
5703 <CGENUS incertae="1" name="Bellusaurus"/>
5704 <CGENUS incertae="1" name="Hudiesaurus" q="1"/>
5705 <CGENUS incertae="1" name="Klamelisaurus"/>
5706 <CGENUS incertae="1" name="Nurosaurus" q="1"/>
5707 <CGENUS incertae="1" name="Tienshanosaurus" q="1"/>
5708 <CGENUS name="Datousaurus"/>
5709 <CGENUS name="Shunosaurus"/>
5710 <CLADE name="Euhelopodinae">
5711 <CSYNONYM name="Mamenchisaurinae"/>
5712 <CGENUS name="Euhelopus"/>
5713 <CGENUS name="Mamenchisaurus"/>
5714 <CGENUS name="Omeisaurus"/>
5720 <CLADOGRAM alternate="1">
5721 <CLADE name="Sauropoda">
5722 <CGENUS name="Vulcanodon"/>
5723 <CLADE name="Eusauropoda" in="Saltasaurus" out="Vulcanodon">
5724 <AUTHOR type="sensu" name="Wilson, Sereno"/>
5725 <CGENUS name="Shunosaurus"/>
5727 <CGENUS name="Barapasaurus"/>
5729 <CGENUS name="Omeisaurus"/>
5731 <CGENUS name="Jobaria"/>
5732 <CLADE name="Neosauropoda"/>
5740 <P> Sauropods were giant, long-necked <LINK content="dinosaurian"/> plant-eaters.
5741 All sauropods were quite large. Even the smallest ones were about as big as
5742 the largest members of other dinosaur groups. </P>
5744 <P header="Diversity"> Early sauropods like <NOMEN name="Vulcanodon"/> resembled
5745 "<LINK content="prosauropods"/>", especially
5746 <LINK content="melanorosaurids"/>. As sauropod evolution progressed,
5747 they became larger and more diverse. There were crested forms
5748 (<LINK content="macronarians"/>), armored forms
5749 (<LINK content="titanosaurs"/>), a plated form (<NOMEN name="Agustinia"/>),
5750 sailback forms (some <LINK content="diplodocimorphs"/>), and a
5751 club-tailed form (<NOMEN name="Shunosaurus"/>), but they were
5752 never quite as diverse as the other two major dinosaurian groups,
5753 <LINK content="Theropoda"/> and <LINK content="Ornithischia"/>. </P>
5755 <P header="Classification"> The eusauropods shown here were often grouped together in Cetiosauridae,
5756 but it is probably a paraphyletic grouping. Vulcanodontidae, consisting of
5757 the non-eusauropod sauropods, is also probably paraphyletic. </P>
5759 <P header="Euhelopodidae or Not Euhelopodidae?"> There is a wide variance
5760 of opinion about this group, if it is a group. Some hold that the
5761 club-tailed <NOMEN name="Shunosaurus"/>, the long-necked euhelopodines
5762 (<NOMEN name="Euhelopus"/>, <NOMEN name="Mamenchisaurus"/>, and <NOMEN
5763 name="Omeisaurus"/>), and some of their relatives form a distinct clade.
5764 More recently, other studies have strewn these animals all over Sauropoda,
5765 placing <NOMEN name="Shunosaurus"/> as a basal <LINK content="sauropod"/>,
5766 <NOMEN name="Omeisaurus"/> as a "<LINK content="cetiosaur"/>"
5767 just outside <LINK content="Neosauropoda"/>, and <NOMEN name="Euhelopus"/>
5768 as a relative of <LINK content="titanosaurs"/>! </P>
5772 <TAXON name="Sauropodomorpha" nickname="Long-Necked Plant-Eaters">
5773 <WORD key="1" content="brontosaur, prosauropod, early, plant, eating, herbivore, herbivourous"/>
5774 <WORD essay="1" content="Prosauropoda, prosauropod, prosauropods"/>
5776 <CLADE name="Sauropodomorpha" in="Saltasaurus" out="Neornithes" silhouette="sauropodomorpha">
5777 <AUTHOR name="von Huene" year="1932"/>
5778 <AUTHOR type="sensu" name="Gauthier" year="1986"/>
5783 <TIME value="MTr" q="1"/>
5784 <TIME value="LTr" q="1"/>
5785 <PLACE name="Madagascar"/>
5788 <TIME value="Carnian"/>
5789 <PLACE name="Brazil"/>
5792 <REMAINS content="teeth"/>
5793 <TIME value="Carnian"/>
5794 <PLACE name="Canada"/>
5798 <PLACE name="U.S.A."/>
5801 <REMAINS content="left maxilla with 12 teeth, rostral parts of jaw, pectoral girdles, forelimbs, vertebrae, ribs, gastralia"/>
5803 <PLACE name="Brazil"/>
5805 <CGENUS name="Gyposaurus sinensis" incertae="1"/>
5806 <CGENUS name="Azendohsaurus"/>
5807 <CGENUS name="Saturnalia"/>
5808 <CGENUS q="1" name="Thecodontosaurus"/>
5809 <CLADE name="Brontosauria" silhouette="sauropodomorpha-large">
5810 <AUTHOR name="Olshevsky" year="1991"/>
5811 <MEANING><NOMEN name="Brontosaurus"/>' <LOW>taxon</LOW>/thunder lizards</MEANING>
5812 <CGENUS name="Gongxianosaurus" incertae="1"/>
5813 <CGENUS name="Mussaurus" incertae="1" silhouette="sauropodomorpha"/>
5814 <CGENUS name="Camelotia" incertae="1"/>
5815 <CGENUS name="Chinshakiangosaurus" incertae="1"/>
5816 <CGENUS name="Thotobolosaurus" incertae="1"/>
5817 <CGENUS name="Yimenosaurus" incertae="1"/>
5818 <CGENUS name="Anchisaurus" silhouette="sauropodomorpha"/>
5819 <CGENUS name="Ammosaurus" silhouette="sauropodomorpha"/>
5820 <CGENUS name="Blikanasaurus"/>
5821 <CLADE name="Melanorosauridae">
5822 <CGENUS name="Hortalotarsus" incertae="1" q="1"/>
5823 <CGENUS name="Lessemsaurus" q="1"/>
5824 <CGENUS name="Melanorosaurus"/>
5825 <CGENUS q="1" name="Microdontosaurus"/>
5826 <CGENUS name="Riojasaurus" q="1"/>
5828 <CLINK name="Sauropoda"/>
5829 <CLADE in="Plateosaurus" out="Saltasaurus">
5830 <CSYNONYM name="Prosauropoda" sensu="Wilson, Sereno"/>
5831 <CLADE name="Plateosauria" in="Plateosaurus, Massospondylus">
5833 <NOMEN name="Plateosaurus"/>' <LOW>taxon</LOW>
5836 <TIME value="MTr" q="1"/>
5837 <TIME value="LTr" q="1"/>
5838 <PLACE name="Madagascar"/>
5841 <PLACE name="Antarctica"/>
5843 <UNNAMED q="1" comment="therizinosaur-like">
5845 <PLACE name="China"/>
5846 <REMAINS content="lower jaw"/>
5848 <CGENUS name="Euskelosaurus" incertae="1" q="1"/>
5849 <CLADE name="Massospondylidae">
5850 <CSYNONYM name="Yunnanosauridae"/>
5851 <CGENUS name="Massospondylus"/>
5852 <CLADE name="Yunnanosaurinae">
5853 <CGENUS name="Jingshanosaurus"/>
5854 <CGENUS name="Yunnanosaurus"/>
5857 <CLADE name="Plateosauridae">
5858 <CGENUS name="Coloradisaurus" q="1"/>
5859 <CGENUS name="Sellosaurus"/>
5860 <CLADE name="Plateosaurinae">
5861 <CGENUS name="Lufengosaurus"/>
5862 <CGENUS name="Plateosaurus"/>
5870 <CLADOGRAM alternate="1">
5871 <CLADE name="Sauropodomorpha">
5872 <CLADE name="Sauropoda"/>
5873 <CLADE name="Prosauropoda" in="Thecodontosaurus, Melanorosaurus, Plateosaurus" out="Saltasaurus">
5877 <CSYNONYM name="Paleopoda"/>
5878 <CGENUS name="Thecodontosaurus"/>
5880 <CGENUS name="Anchisaurus"/>
5882 <CGENUS name="Ammosaurus"/>
5884 <CLADE name="Yunnanosauridae"/>
5886 <CGENUS name="Sellosaurus"/>
5887 <CLADE name="Plateosauridae"/>
5889 <CGENUS name="Blikanasaurus"/>
5890 <CLADE name="Melanorosauridae"/>
5899 <CLADOGRAM alternate="1">
5900 <CLADE name="Sauropodomorpha">
5901 <CLADE name="Sauropoda"/>
5902 <CLADE name="Prosauropoda">
5903 <CGENUS name="Riojasaurus"/>
5904 <CGENUS name="Gyposaurus sinensis"/>
5906 <CGENUS name="Ammosaurus"/>
5907 <CLADE name="Plateosauria" in="Plateosaurus, Massospondylus">
5908 <CLADE name="Plateosauridae"/>
5909 <CLADE name="Massospondylidae">
5910 <CSYNONYM name="Yunnanosauridae"/>
5911 <CGENUS name="Massospondylus"/>
5912 <CGENUS name="Yunnanosaurus"/>
5919 <CLADOGRAM alternate="1">
5920 <CLADE name="Sauropodomorpha">
5921 <CGENUS name="Thecodontosaurus"/>
5923 <CGENUS name="Anchisaurus"/>
5926 <CGENUS name="Yunnanosaurus"/>
5927 <CLADE name="Sauropoda"/>
5930 <CGENUS name="Sellosaurus"/>
5932 <CGENUS name="Plateosaurus"/>
5934 <CGENUS name="Blikanasaurus"/>
5935 <CLADE name="Melanorosauridae"/>
5944 <P> Sauropodomorphs were the long necked, herbivorous, lizard-hipped
5945 <LINK content="dinosaurs"/>, including the largest land animals of all
5948 <P header='The "Prosauropods"'> The primitive sauropodomorphs listed
5949 here are commonly called
5950 "prosauropods". These were semi-quadrupedal herbivores from the
5951 <LINK content="Triassic"/> and <LINK content="Early Jurassic"/> with large,
5952 hooked claws on their feet. They were once thought to be omnivorous, since
5953 <LINK content="theropod"/> teeth found with them were often mistakenly
5954 thought to be the teeth of the prosauropods themselves. Instead, they were
5955 the largest herbivores of their day (although primitive ones may have been
5958 <P> It is not certain whether "prosauropods" gave rise to the larger
5959 <LINK content="sauropods"/>, or if they are just the sister group to
5960 Sauropoda. No cladistic analysis has yet been done to test "prosauropod"
5961 monophyly. All to date have simply assumed monophyly based on the
5962 fact that prosauropods lack a digit that sauropods possess, lack of a digit
5963 usually being a derived trait, not a primitive one. </P>
5965 <P header="Brontosauria">
5966 The taxon Brontosauria was originally designated for a group containing
5967 Sauropoda and Prosauropoda, considered paraphyletic by its author. Here
5968 it has been cladistically translated as the node containing Sauropoda
5969 and Prosauropoda (<I>sensu</I> Wilson & Sereno), although this definition
5970 has not yet been used formally, to my knowledge. </P>
5974 <TAXON name="Sauropsida" nickname="Scaly Ones" simple="1">
5975 <WORD key="1" content="reptilian, monster, evolution, origin"/>
5976 <INCLUDED content="Mesosaurus"/>
5978 <CLADE name="Sauropsida" in="Reptilia" out="Mammalia" silhouette="sauropsida">
5982 <CLADE extinct="1" name="Mesosauridae" content='"sauropsid otters"'/>
5983 <CLADE name="Reptilia" in="Crocodylia, Squamata, Sphenodon, Chelonia">
5984 <AUTHOR name="Linnaeus"/>
5985 <AUTHOR type="sensu" name="Gauthier" year="1984"/>
5989 <CLINK name="Anapsida"/>
5990 <CLADE name="Romeriida" in="Sauria" out="Chelonia">
5992 Romer's <LOW>taxon</LOW>
5994 <CLADE extinct="1" name="Batropetidae" q="1"/>
5995 <CLADE extinct="1" name="Bolosauridae" q="1"/>
5996 <CLADE extinct="1" name="Captorhinidae"/>
5998 <CLADE extinct="1" name="Protorothyrididae" paraphyletic="1"/>
5999 <CLADE name="Diapsida" comment="two temporal fenestrae, at least primitively">
6003 <CGENUS extinct="1" incertae="1" name="Longisquama"/>
6004 <CLADE extinct="1" name="Endennasauridae" q="1"/>
6005 <CLADE extinct="1" name="Mesenosauridae" q="1"/>
6006 <CLADE extinct="1" name="Araeoscelida">
6007 <CLADE extinct="1" name="Araeoscelidae"/>
6008 <CLADE extinct="1" name="Petrolacosauridae"/>
6010 <CLADE name="Neodiapsida">
6014 <CLADE extinct="1" name="Coelurosauravidae"/>
6015 <CLADE extinct="1" name="Thalattosauria" q="1">
6016 <CLADE extinct="1" name="Askeptosauridae"/>
6017 <CLADE extinct="1" name="Claraziidae"/>
6018 <CLADE extinct="1" name="Thalattosauridae"/>
6020 <CLADE incertae="1">
6021 <CGENUS extinct="1" name="Lazarussaurus"/>
6022 <CLADE extinct="1" name="Choristodera">
6023 <CSYNONYM name="Champsosauria"/>
6024 <CGENUS extinct="1" name="Cteniogenys"/>
6025 <CLADE extinct="1" name="Neochoristodera">
6026 <CLADE extinct="1" name="Champsosauridae"/>
6027 <CLADE extinct="1" name="Simedosauridae"/>
6031 <CLADE name="Sauria" in="Crocodylia, Squamata, Sphenodon">
6035 <CLINK name="Ichthyopterygia" q="1"/>
6036 <CLINK name="Sauropterygia" q="1"/>
6037 <CLINK name="Lepidosauromorpha"/>
6038 <CLINK name="Archosauromorpha"/>
6048 <P> Sauropsida is one of the two great lineages of
6049 <LINK content="amniote"/> (the other being <LINK content="Synapsida"/>,
6050 which includes <LINK content="Mammalia"/>). All sauropsids, except for
6051 primitive forms like mesosaurids, belong to the clade Reptilia. </P>
6053 <P header="History of Classification"> Reptilia was once a "grab-bag" taxon for every amniote that was neither
6054 a <LINK content="bird"/> nor a mammal. It was divided into four sections based
6055 on the number and alignment of certain holes in the back of the skull
6056 (temporal fenestrae): Anapsida (no holes), Synapsida (a low hole),
6057 Euryapsida (a high hole), and Diapsida (two holes -- includes
6058 <LINK content="dinosaurs"/>). </P>
6060 <P> Reptilia has since been re-defined as a clade: all the descendants of the
6061 most recent common ancestor of the four living groups considered reptiles:
6062 <LINK content="Chelonia"/> (turtles), <NOMEN nolink="1" name="Sphenodon"/> (tuatara),
6063 <LINK content="Squamata"/> (lizards and snakes), and <LINK content="Crocodylia"/>
6064 (crocodiles and kin). This definition excludes some creatures once considered
6065 reptiles (Synapsida -- formerly called "mammal-like reptiles"), and
6066 includes some creatures previously not considered reptilian
6067 <LINK content="Aves"/> -- birds). </P>
6069 <P> The groups Anapsida and Diapsida are still used as clades within Reptilia,
6070 slightly modified from their traditional meanings (Anapsida now excludes
6071 the most primitive sauropsids; Diapsida now includes birds). "Euryapsida",
6072 which included marine reptiles such as <LINK content="ichthyosaurs"/> and
6073 <LINK content="plesiosaurs"/>, is now recognized as an unnatural grouping of
6074 various aberrant diapsid lineages which lost their lower temporal
6077 <P header="Domination"> The <LINK content="Mesozoic"/> is often called "The Age of Reptiles"
6078 because of the reptilian dominance during most of that era. Dinosaurs ruled
6079 the land, <LINK content="pterosaurs"/> ruled the skies, and a great variety
6080 of marine reptiles <LINK content="mosasaurs"/>, plesiosaurs, ichthyosaurs,
6081 etc.) ruled the oceans. Most of these creatures died out in the K-T
6082 extinction (ichthyosaurs died out earlier; champsosaurs, a freshwater
6083 lineage, later). </P>
6087 <TAXON name="Sauropterygia" nickname="Flipper Reptiles - Longnecks & Bigheads" simple="1">
6088 <WORD key="1" content="loch, ness, pliosaurs, marine, sea, sea-going, oceanic, aquatic, swimming"/>
6089 <INCLUDED content="Cryptoclidus, Elasmosaurus, Kronosaurus, Leptocleidus, Plesiosaurus, Muraenosaurus"/>
6091 <CLADE name="Sauropterygia" silhouette="sauropterygia">
6095 <CLADE name="Placodontia" content='"reptilian walruses"'>
6096 <CLADE name="Helveticosauridae"/>
6097 <CLADE name="Placodontoidea">
6098 <CGENUS name="Chelyoposuchus"/>
6099 <CLADE name="Cyamodontidae"/>
6100 <CLADE name="Henodontidae"/>
6101 <CLADE name="Placodontidae"/>
6105 <CLADE name="Claudiosauridae" q="1"/>
6106 <CLADE name="Eusauropterygia">
6108 true sauropterygians
6110 <CGENUS name="Corosaurus"/>
6111 <CGENUS name="Simosaurus"/>
6112 <CLADE name="Nothosauridae"/>
6113 <CLADE name="Pachypleurosauridae"/>
6115 <CGENUS name="Cymatosaurus"/>
6117 <CGENUS name="Pistosaurus"/>
6118 <CLADE name="Plesiosauria">
6120 <NOMEN nolink="1" name="Plesiosaurus"/>' <LOW>taxon</LOW>
6122 <CLADE name="Pliosauridae"/>
6123 <CLADE name="Plesiosauroidea">
6124 <CLADE name="Plesiosauridae"/>
6126 <CLADE name="Cryptoclididae"/>
6128 <CLADE name="Elasmosauridae"/>
6129 <CLADE name="Polycotylidae"/>
6141 <P> Sauropterygians were a group of marine reptiles of uncertain origin. At times
6142 allied to <LINK content="turtles"/> or <LINK content="prolacertiforms"/>, they are probably
6143 <LINK content="diapsids"/>, possibly a basal lineage of either
6144 <LINK content="Lepidosauromorpha"/> or <LINK content="Archosauromorpha"/>. </P>
6146 <P header="Characteristics and Niches"> Their limbs had evolved into
6147 flippers, which they used to swim through the
6148 <LINK content="Mesozoic"/> seas. The advanced sauropterygians, plesiosaurs,
6149 came in two main body forms. Pliosaurs had long, large heads, and short necks,
6150 similar to the distantly related <LINK content="mosasaurs"/>. Plesiosauroids
6151 had extremely long necks with tiny heads, looking something like a cross
6152 between a <LINK content="sea turtle"/> and a <LINK content="snake"/>.
6153 All sauropterygians were carnivorous. </P>
6155 <P> Placodonts may or may not have been sauropterygians. They were
6156 large, probably sluggish creatures somewhat similar in form to today's
6157 <LINK content="walruses"/> and <LINK content="sirenians"/>
6158 (manatees and dugongs). Their broad teeth splayed outward from their mouths.
6159 It has been suggested that they used them to crush <LINK content="mollusk"/>
6162 <P header="The End"> Sauropterygians died out at the end of the <LINK content="Cretaceous"/>,
6163 along with all non-<LINK content="neornithean"/> <LINK content="dinosaurs"/>.
6164 There have been reports of modern-day populations of plesiosauroids, but
6165 these have either turned out to be other animals (rotting basking shark
6166 carcasses) or deliberate hoaxes (the Loch Ness monster). </P>
6170 <TAXON name="Spinosauria" nickname="Sail-Backed Crocodile-Mimics">
6171 <WORD key="1" content="sail, back, backed, sail-backed, sailbacked, finback, fin, crocodiles, sails, fins"/>
6173 <CLADE name="Spinosauria" silhouette="spinosauria">
6175 <NOMEN name="Spinosaurus"/>' <LOW>taxon</LOW>
6177 <CGENUS incertae="1" q="1" name="Siamosaurus"/>
6178 <CLADE name="Spinosauridae" in="Spinosaurus, Baryonyx">
6179 <AUTHOR name="Stromer" year="1915"/>
6180 <CSYNONYM name="Spinosauroidea" sensu="Charig, Milner" year="1997"/>
6181 <CLADE name="Baryonychinae" in="Baryonyx" out="Spinosaurus">
6182 <AUTHOR type="implied" name="Charig, Milner" year="1986"/>
6183 <CSYNONYM name="Baryonychidae" sensu="Charig, Milner" year="1986"/>
6184 <CGENUS name="Cristatusaurus" incertae="1"/>
6185 <CGENUS name="Baryonyx"/>
6186 <CGENUS name="Suchomimus"/>
6188 <CLADE name="Spinosaurinae" in="Spinosaurus" out="Baryonyx">
6189 <AUTHOR type="implied" name="Stromer" year="1915"/>
6190 <CSYNONYM name="Spinosauridae" sensu="Charig, Milner" year="1986"/>
6191 <CGENUS name="Spinosaurus"/>
6192 <CLADE name="Irritatorini">
6193 <AUTHOR type="implied" name="Martill, al." year="1996"/>
6194 <CGENUS name="Angaturama"/>
6195 <CGENUS name="Irritator"/>
6202 <P> Spinosauria once included all theropods with tall vertebral spines. Some
6203 of these creatures, such as <NOMEN name="Acrocanthosaurus"/> and
6204 <NOMEN name="Becklespinax"/>, have since been allied to other groups. </P>
6206 <P header="Physical Characteristics"> Spinosaurs all have <LINK content="crocodile"/>-like conical teeth. Their
6207 long snouts have kinks like those of <LINK content="coelophysids"/> and some
6208 early <LINK content="synapsids"/>. It is thought that they used these for
6209 fishing, possibly in conjunction with other carnivorous activities. </P>
6211 <P> Baryonychines have more teeth at the end of their lower jaw than
6212 spinosaurines. Spinosaurines are characterized by straight, unserrated
6217 <TAXON name="Stegosauria" nickname="Plated Dinosaurs" silhouette="stegosaurinae">
6218 <WORD key="1" content="stegosaurians, plates, plated, spikes, armored, armor, armoured, thermoregulation"/>
6220 <CLADE name="Stegosauria" in="Stegosaurus, Ankylosaurus" silhouette="stegosauria">
6221 <MEANING><NOMEN nolink="1" name="Stegosaurus"/>' <LOW>taxon</LOW></MEANING>
6223 <TIME value="Aalenian" q="1"/>
6224 <PLACE name="Scotland"/>
6225 <REMAINS content="partial arm bones"/>
6227 <CGENUS incertae="1" name="Changtusaurus"/>
6228 <CGENUS incertae="1" name="Craterosaurus"/>
6229 <CGENUS incertae="1" name="Gigantspinosaurus"/>
6230 <CGENUS incertae="1" name="Katsuyamakensaurus"/>
6231 <CGENUS incertae="1" name="Regnosaurus"/>
6232 <CLADE name="Huayangosauridae" in="Huayangosaurus" out="Stegosaurus">
6233 <CGENUS name="Huayangosaurus"/>
6235 <CLADE name="Stegosauridae" in="Stegosaurus" out="Huayangosaurus" silhouette="stegosauridae">
6237 <TIME value="LJ" section="late"/>
6238 <PLACE name="U.S.A."/>
6241 <TIME value="Hauterivian"/>
6242 <PLACE name="Argentina"/>
6244 <CGENUS incertae="1" name="Monkonosaurus"/>
6245 <CGENUS incertae="1" name="Yingshanosaurus"/>
6246 <CGENUS name="Dacentrurus"/>
6248 <CGENUS name="Kentrosaurus"/>
6250 <CGENUS name="Chialingosaurus"/>
6251 <CGENUS name="Chungkingosaurus"/>
6252 <CLADE name="Stegosaurinae" silhouette="stegosaurinae">
6253 <CGENUS name="Lexovisaurus"/>
6254 <CGENUS name="Paranthodon" q="1"/>
6255 <CGENUS name="Tuojiangosaurus"/>
6256 <CLADE name="Stegosaurini">
6257 <CGENUS name="Stegosaurus"/>
6258 <CGENUS name="Wuerhosaurus"/>
6267 <P header='"Roofed Reptiles"'> These primarily <LINK
6268 content="Jurassic"/> herbivores had two rows of
6269 plates and/or spikes going down the back. </P>
6271 <P> Although the spikes, which were usually found on the tail, were certainly
6272 used for defense, the exact purpose of the plates is unknown. They could
6273 not have made very effective armor, since they left the sides completely
6274 exposed. Perhaps they performed a similar function to the sails of
6275 <NOMEN name="Spinosaurus"/>, <NOMEN name="Ouranosaurus"/>, and
6276 <NOMEN name="Rebbachisaurus"/>, whatever that
6277 function was (possibly heat regulation, sexual display, or both). </P>
6279 <P header="The End"> Stegosaurs did not last to the end of the <LINK content="Mesozoic Era"/>,
6280 but died out during the <LINK content="Cretaceous Period"/>, possibly due to
6281 competition from other <LINK content="ornithischian"/> herbivores or from a
6282 change in flora (the transition from gymnosperms to angiosperms) which they
6283 could not adapt to. One creature which was thought to be a
6284 <LINK content="Late Cretaceous"/> stegosaur (<NOMEN name="Dravidosaurus"/>)
6285 has turned out to be a <LINK content="plesiosaur"/>! (This is not the only
6286 time marine <LINK content="vertebrate"/> remains have been mistaken for
6287 stegosaur remains -- the plates of
6288 <NOMEN name="Lexovisaurus durobrivensis"/> turned out to be gill
6289 rakers from a fish!) </P>
6293 <TAXON name="Synapsida" nickname="Mammals and Kin" simple="1">
6294 <WORD key="1" content="proto-mammals, proto, mammals, mammal-like, like, pelycosaurian, sailbacked, sail, back, fin, finbacked, backed"/>
6295 <WORD essay="1" key="1" content="pelycosaurs"/>
6296 <INCLUDED content="Cynognathus, Edaphosaurus, Dimetrodon, Lycaenops, Lystrosaurus, Moschops, Titanopheus"/>
6298 <CLADE name="Synapsida" in="Mammalia" out="Reptilia" silhouette="synapsida">
6302 <CSYNONYM name="Theropsida"/>
6303 <CLADE name="Caseasauria" in="Casea" out="Mammalia">
6305 <NOMEN nolink="1" name="Casea"/> lizards
6307 <CLADE name="Caseidae"/>
6308 <CLADE name="Eothyrididae"/>
6310 <CLADE name="Eupelycosauria" in="Mammalia" out="Casea">
6314 <CLADE name="Varanopsidae"/>
6316 <CLADE name="Ophiacodontidae"/>
6318 <CLADE name="Edaphosauridae"/>
6319 <CLADE name="Sphenacodontia">
6321 <NOMEN nolink="1" name="Sphenacodon"/>'s <LOW>taxon</LOW>
6323 <CGENUS name="Haptodus"/>
6325 <CGENUS name="Palaeohatteria"/>
6327 <CGENUS name="Pantelosaurus"/>
6329 <CGENUS name="Cutleria"/>
6330 <CLADE name="Sphenacodontoidea" in="Sphenacodon, Mammalia">
6331 <CLADE name="Sphenacodontidae" content="Dimetrodon, Sphenacoon, etc."/>
6332 <CLADE name="Therapsida" in="Mammalia" out="Sphenacodon">
6336 <CSYNONYM name="Neotheropsida"/>
6337 <CLADE name="Biarmosuchia"/>
6339 <CLADE name="Dinocephalia" content="Moschops, etc.">
6345 <CLADE name="Anomodontia">
6346 <CLADE name="Dromasauria"/>
6347 <CLADE name="Venyukiamorpha"/>
6348 <CLADE name="Dicynodontia"/>
6350 <CLADE name="Theriodontia">
6351 <CLADE name="Gorgonopsia" content="Lycaenops, etc."/>
6353 <CLADE name="Therocephalia">
6358 <CLADE name="Cynodontia">
6362 <CLADE name="Dviniidae"/>
6363 <CLADE name="Galesauridae"/>
6364 <CLADE name="Procynosuchidae"/>
6365 <CLADE name="Eucynodontia" in="Cynognathus, Mammalia">
6369 <CLADE name="Cynognathidae"/>
6370 <CLADE name="Probainognathia">
6371 <CLADE name="Tritylodontoidea"/>
6373 <CGENUS name="Eoraetia" q="1"/>
6374 <CGENUS name="Kunminia" q="1"/>
6375 <CLADE name="Chiniquodontidae"/>
6376 <CLADE name="Tritheledontidae"/>
6377 <CLADE name="Mammaliformes">
6381 <CSYNONYM name="Mammalia" sensu="lato"/>
6382 <CGENUS name="Adelobasilus" q="1"/>
6383 <CGENUS name="Sinoconodon" q="1"/>
6384 <CGENUS name="Theroteinus" q="1"/>
6385 <CGENUS name="Tricuspes" q="1"/>
6386 <CLADE name="Gobiconodontidae" q="1"/>
6388 <CLADE name="Morganucodontidae" q="1"/>
6390 <CLADE name="Docodonta" q="1"/>
6391 <CLINK name="Mammalia"/>
6415 <P> Once called <LINK content="mammal"/>-like <LINK content="reptiles"/>,
6416 the animals shown here are no longer considered reptiles. Instead, they were
6417 the non-mammalian members of a separate lineage. Their skin was
6418 not scaly like true reptiles. </P>
6420 <P header="Evolutionary Dynasties"> Synapsids were the first terrestrial vertebrates to truly dominate the
6421 landscape. There were two main "waves", the "pelycosaurs" (non-therapsid
6422 synapsids) in the Permian and then the therapsids in the
6423 <LINK content="Triassic"/>. </P>
6425 <P> "Pelycosaurs" were probably cold-blooded. They ranged from large
6426 herbivores like <NOMEN nolink="1" name="Casea"/> to snaggle-toothed,
6427 sail-backed predators like <NOMEN nolink="1" name="Dimetrodon"/>.
6428 The advanced ones show the beginnings of the mammalian tooth pattern -- incisors,
6429 canines, and molars. </P>
6431 <P> Some (but probably not all) therapsids were warm-blooded, fur-covered,
6432 and milk-giving. They varied from the beaked, tusked, and herbivorous
6433 dicynodonts to the sleek, predatory <NOMEN nolink="1" name="Cynognathus"/>.
6434 By the end of the Triassic, most of these forms had died out, replaced by
6435 <LINK content="archosaurs"/> (including <LINK content="dinosaurs"/>). The
6436 only survivors were a group of small, furry cynodonts: the mammals. </P>
6440 <TAXON name="Tetanurae" nickname="Three-Fingered Meat-Eaters">
6441 <WORD key="1" content="tetanurines, megalosaurs, predators, carnivorous, flesh, meat, hunters, carnivores"/>
6442 <WORD essay="1" content="megalosaur, megalosaurs"/>
6444 <CLADE name="Tetanurae" in="Neornithes" out="Ceratosaurus" silhouette="tetanurae">
6445 <AUTHOR name="Gauthier" year="1986"/>
6450 <REMAINS content="pedal phalanx, caudal centrum"/>
6452 <PLACE name="Mississippi"/>
6455 <TIME value="Callovian"/>
6456 <PLACE name="France"/>
6457 <REMAINS content="braincase"/>
6459 <UNNAMED cf="Erectopus">
6460 <TIME value="Albian"/>
6461 <TIME value="Cenomanian" section="early"/>
6462 <PLACE name="Africa"/>
6464 <UNNAMED comment="tall-spined" silhouette="acrocanthosaurus">
6465 <PLACE name="England"/>
6468 <CGENUS incertae="1" name="Allosaurus sp."/>
6469 <CGENUS incertae="1" name="Altispinax"/>
6470 <CGENUS incertae="1" name="Becklespinax" silhouette="acrocanthosaurus"/>
6471 <CGENUS incertae="1" name="Brontoraptor"/>
6472 <CGENUS incertae="1" q="1" name="Calamospondylus" silhouette="neotheropoda"/>
6473 <CGENUS name="Eustreptospondylus" incertae="1"/>
6474 <CGENUS incertae="1" name="Kaijiangosaurus"/>
6475 <CGENUS incertae="1" name="Magnosaurus"/>
6476 <CGENUS incertae="1" name="Megalosaurus andrewsi"/>
6477 <CGENUS incertae="1" name="Metriacanthosaurus"/>
6478 <CGENUS incertae="1" name="Newtonsaurus"/>
6479 <CGENUS incertae="1" name="Piatnitzkysaurus"/>
6480 <CGENUS incertae="1" name="Streptospondylus"/>
6481 <CGENUS incertae="1" name="Walkersaurus"/>
6482 <CGENUS incertae="1" name="Wyomingraptor"/>
6483 <CGENUS incertae="1" name="Xuanhanosaurus"/>
6484 <CSYNONYM name="Avipoda" q="1"/>
6485 <CLADE in="Neornithes, Torvosaurus">
6486 <CSYNONYM name="Tetanurae" sensu="Sereno"/>
6487 <CSYNONYM name="Spinosauroidea" sensu="Sereno" q="1"/>
6488 <CLADE name="Torvosauridae" in="Torvosaurus" out="Spinosaurus">
6489 <CSYNONYM name="Megalosauridae"/>
6490 <CSYNONYM name="Eustreptospondylidae" q="1"/>
6491 <CGENUS name="Edmarka"/>
6492 <CGENUS name="Megalosaurus"/>
6493 <CGENUS name="Poekilopleuron"/>
6494 <CGENUS name="Torvosaurus"/>
6497 <CGENUS name="Afrovenator" q="1"/>
6498 <CLINK name="Spinosauria"/>
6499 <CLADE name="Neotetanurae" in="Neornithes, Allosaurus">
6500 <MEANING>new tetanurans</MEANING>
6501 <AUTHOR name="Sereno, al." year="1994"/>
6502 <CSYNONYM name="Avetheropoda">
6503 <AUTHOR name="Paul" year="1988"/>
6504 <AUTHOR type="sensu" name="Holtz" year="1994"/>
6506 <CSYNONYM name="Tetanurae" sensu="Novas"/>
6507 <CGENUS incertae="1" name="Chingkankousaurus"/>
6508 <CGENUS incertae="1" name="Erectopus"/>
6509 <CGENUS incertae="1" name="Marshosaurus"/>
6510 <CGENUS incertae="1" name="Walgettosuchus"/>
6511 <CLINK name="Carnosauria"/>
6512 <CLINK name="Coelurosauria"/>
6518 <CLADOGRAM alternate="1">
6519 <CLADE name="Tetanurae">
6520 <CLADE name="Neotetanurae"/>
6521 <CLADE name="Spinosauroidea" in="Spinosaurus, Torvosaurus">
6522 <AUTHOR type="sensu" name="Sereno"/>
6523 <CSYNONYM name="Megalosauroidea"/>
6524 <CSYNONYM name="Torvosauroidea"/>
6525 <CLADE name="Spinosauridae" in="Spinosaurus" out="Torvosaurus">
6526 <AUTHOR type="sensu" name="Sereno"/>
6528 <CLADE name="Torvosauridae"/>
6533 <P> Tetanurae consists of the advanced <LINK content="theropods"/>,
6534 including <LINK content="birds"/> and their ancestors. Tetanurans are
6535 characterized by three fingers or less, an opening in the skull between the
6536 antorbital fenestra and the naris (nostril) called the maxillary fenestra, and
6537 stiffened tails (Tetanurae means "stiffened tails"). </P>
6539 <P header="Classification and History"> The non-neotetanuran groups listed
6540 here are sometimes grouped together in a group sometimes called
6541 Megalosauria or Megalosauroidea, although this is probably a paraphyletic
6542 group, as shown here. Most "megalosaurs" were large carnivores. Some think
6543 <LINK content="Spinosauridae"/> and Torvosauridae (=Megalosauridae) make a
6544 group, sharing enlarged, sickle-shaped thumb claws. </P>
6546 <P> <NOMEN name="Megalosaurus"/> was the first
6547 non-<LINK content="neornithean"/> <LINK content="dinosaur"/> to be
6548 described. The family Megalosauridae was once a grab-bag for all sorts of
6549 large theropods: <LINK content="spinosaurs"/>, <LINK content="allosaurs"/>,
6550 large <LINK content="ceratosaurs"/>, large <LINK content="coelurosaurs"/>
6553 <P header="Advanced Characteristics"> Neotetanurans, an advanced group of tetanurans, had complex air
6554 passages in their vertebrae and ribs. The furcula, a bone which is not always
6555 preserved, has been found in a <LINK content="carnosaur"/>
6556 (<NOMEN name="Allosaurus"/>) and several <LINK content="coelurosaurs"/>, so
6557 it seems to be a neotetanuran trait as well. </P>
6561 <TAXON name="Tetrapoda" nickname="Terrestrial Vertebrates" simple="1">
6562 <WORD key="1" content="terrestrial, land, amniotic"/>
6563 <INCLUDED content="Acanthostega, Limnoscelis, Siderops"/>
6565 <CLADE name="Tetrapoda" silhouette="tetrapoda">
6569 <CLADE extinct="1" name="Elginerpetonidae"/>
6572 <CGENUS extinct="1" name="Metaxygnathus" q="1"/>
6573 <CGENUS extinct="1" name="Ventistega"/>
6576 <CGENUS extinct="1" name="Acanthostega"/>
6578 <CGENUS extinct="1" name="Ichthyostega"/>
6580 <CGENUS extinct="1" name="Antlerpeton" q="1"/>
6581 <CGENUS extinct="1" name="Hynerpeton"/>
6583 <CGENUS extinct="1" name="Tulerpeton"/>
6585 <CGENUS extinct="1" name="Crassigyrinus"/>
6587 <CLADE extinct="1" name="Temnospondyli"/>
6589 <CGENUS extinct="1" name="Whatcheeria"/>
6591 <CLADE extinct="1" name="Embolomeri"/>
6593 <CLADE extinct="1" name="Gephyrostegida"/>
6595 <CGENUS extinct="1" name="Solenodonsaurus" q="1"/>
6596 <CLADE extinct="1" name="Chroniosuchidae" q="1"/>
6597 <CLADE extinct="1" name="Limnoscelidae" q="1"/>
6598 <CLADE extinct="1" name="Seymouriamorpha"/>
6599 <CLADE extinct="1" name="Nycteroleteridae" q="1"/>
6600 <CLADE extinct="1" name="Tokosauridae" q="1"/>
6601 <CLADE extinct="1" name="Tseajaiidae" q="1"/>
6602 <CLADE in="Lissamphibia, Amniota">
6603 <CSYNONYM name="Tetrapoda" sensu="stricto"/>
6604 <CLADE name="Amphibia" content="frogs, salamanders, blindworms, etc." in="Lissamphibia" out="Amniota">
6609 <CLADE name="Amniotomorpha" in="Amniota" out="Lissamphibia">
6613 <CLADE extinct="1" name="Lysorophia" q="1"/>
6615 <CGENUS extinct="1" name="Westlothiana"/>
6616 <CLADE name="Amniotiformes" status="informal">
6620 <CLADE extinct="1" name="Diadectomorpha"/>
6621 <CLADE name="Amniota" in="Reptilia, Mammalia" comment="possess amniotic sac in egg">
6622 <CLADE extinct="1" name="Acleistorhinidae" q="1"/>
6623 <CLINK name="Synapsida"/>
6624 <CLINK name="Sauropsida"/>
6644 <P> Among terrestrial vertebrates, <LINK content="dinosaurs"/> belong to
6645 Amniota, a clade characterized by the ability to procreate on land. Of the
6646 two main branches of amniotes, dinosaurs belong to
6647 <LINK content="Sauropsida"/>, which includes other
6648 <LINK content="reptiles"/> as well. The sister clade to Sauropsida,
6649 <LINK content="Synapsida"/>, includes <LINK content="mammals"/>. </P>
6653 <TAXON name="Therizinosauria" nickname="Weirdest of the Weird">
6654 <WORD key="1" content="scythe, sickle, feathers, feathered, integument, skin, impressions"/>
6656 <CLADE name="Therizinosauria" in="Therizinosaurus" out="Oviraptor, Ornithomimus, Troodon" silhouette="therizinosauria">
6657 <AUTHOR type="sensu" name="D. A. Russell" year="1997"/>
6658 <AUTHOR type="emended" name="herein"/>
6660 <NOMEN name="Therizinosaurus"/>' <LOW>taxon</LOW>
6662 <CSYNONYM name="Segnosauria"/>
6663 <CSYNONYM name="Segnosaurischia"/>
6665 <PLACE name="Utah"/>
6666 <TIME value="Aptian"/>
6667 <TIME value="Albian"/>
6669 <UNNAMED cf="Erlikosaurus" q="1" incertae="1">
6670 <TIME section="middle-late" value="Campanian"/>
6671 <PLACE name="Alberta"/>
6672 <REMAINS content="frontal"/>
6674 <CGENUS name="Chilantaisaurus zheziangensis" incertae="1"/>
6675 <CGENUS q="1" name="Beipiaosaurus"/>
6676 <CLADE name="Therizinosauroidea" in="Therizinosaurus, Alxasaurus">
6677 <AUTHOR type="implied" name="Maleev" year="1954"/>
6678 <AUTHOR type="sensu" name="D. A. Russell, Dong" year="1995"/>
6679 <CSYNONYM name="Segnosauroidea"/>
6680 <CLADE name="Alxasauridae" in="Alxasaurus" out="Therizinosaurus">
6681 <AUTHOR name="D. A. Russell, Dong" year="1995"/>
6682 <CGENUS name="Alxasaurus"/>
6684 <CLADE name="Therizinosauridae" in="Therizinosaurus" out="Alxasaurus">
6685 <AUTHOR name="Maleev" year="1954"/>
6686 <AUTHOR type="non" name="Sereno" year="1999"/>
6687 <CSYNONYM name="Segnosauridae"/>
6688 <CGENUS q="1" name="Nanshiungosaurus bohlini"/>
6689 <CGENUS name="Enigmosaurus"/>
6690 <CGENUS name="Erlikosaurus"/>
6691 <CGENUS name="Nanshiungosaurus"/>
6692 <CGENUS name="Segnosaurus"/>
6693 <CGENUS name="Therizinosaurus"/>
6699 <P header="A Puzzler"> These Asian <LINK content="dinosaurs"/> pose some taxonomic problems. They were
6700 originally classified as <LINK content="theropods"/>, although they have
6701 some features very uncharacteristic for theropods. Their hips are
6702 bird-like, although some theropods such as the <LINK
6703 content="dromaeosaurids"/> and <LINK content="birds"/> themselves have
6704 bird-like hips as well. The front of the snout is a toothless beak,
6705 although <LINK content="oviraptorids"/>, <LINK content="ornithomimids"/>,
6706 and several <LINK content="avian"/> lineages have toothless beaks as well.
6707 But the feet, which have four functional, forward-facing toes, are utterly
6708 unlike any other theropod feet. Except for some <LINK
6709 content="modern birds"/>, all theropods have three functional toes and a
6710 reduced dewclaw. </P>
6712 <P header="Competing Viewpoints"> Another theory was that they were an
6713 outgroup to the <LINK content="ornithischians"/>, since ornithischians have
6714 bird-like hips (although they are only superficially bird-like), beaks, and,
6715 in the most primitive ornithischians, four toes. It has also been proposed
6716 that they are late-surviving relatives of
6717 "<LINK content="prosauropods"/>", since their teeth and feet are
6718 similar to those of "prosauropods". (They are similar enough that
6719 one jawbone from the Early Jurassic of China was published as the earliest
6720 therizinosaur, although it is more likely a "prosauropod".) </P>
6722 <P header="A Consensus (Sort Of)"> The discovery of <NOMEN name="Alxasaurus"/>,
6723 a therizinosaur more primitive than those previously known, seemed to bolster
6724 the theropod theory, as it had some <LINK content="coelurosaurian"/>
6725 features. More recently, the discovery of an even more primitive
6726 therizinosaur, <NOMEN name="Beipiaosaurus"/>, solidifies the therizinosaurs'
6727 status as theropods, since it has a dewclaw. Interestingly, it also has
6728 impressions of feathers or feather-like integument. </P>
6730 <P> There is still disagreement over which coelurosaurian group
6731 therizinosaurs are related to. They have been allied with <LINK
6732 content="deinonychosaurs"/>, <LINK content="ornithomimosaurs"/>, and <LINK
6733 content="oviraptorosaurs"/>. <NOMEN name="Beipiaosaurus"/> has
6734 oviraptorosaur-like features in its pelvis. </P>
6738 <TAXON name="Theropoda" nickname="Meat-Eaters & Kin" silhouette="neotheropoda">
6739 <WORD key="1" content="predatory, predator, carnivorous, flesh, meat, carnivore, raptor, meat-eating, flesh-eating, hunter, bird, avian, herrerasaur, staurikosaur"/>
6741 <CLADE name="Theropoda" in="Neornithes" out="Saltasaurus" silhouette="dinosauria">
6742 <AUTHOR name="Marsh" year="1881"/>
6746 <CSYNONYM name="Goniopoda"/>
6748 <PLACE name="New Zealand"/>
6750 <CGENUS name="Aniksosaurus" incertae="1"/>
6751 <CGENUS name="Arctosaurus" incertae="1" q="1"/>
6752 <CGENUS name="Carnosaurus" incertae="1" q="1"/>
6753 <CGENUS name="Coelurosaurus" incertae="1" q="1"/>
6754 <CGENUS name="Dolichosuchus" incertae="1" q="1"/>
6755 <CGENUS name="Protoavis" incertae="1"/>
6756 <CGENUS name="Rileyasuchus" incertae="1"/>
6757 <CGENUS name="Sinosaurus" incertae="1"/>
6758 <CGENUS name="Spinosuchus" incertae="1" q="1"/>
6759 <CGENUS name="Spondylosoma" incertae="1" q="1"/>
6760 <CGENUS name="Velocipes" incertae="1" q="1"/>
6761 <CGENUS name="Eoraptor"/>
6763 <UNNAMED comment="large">
6764 <PLACE name="S. America"/>
6766 <UNNAMED comment="large, primitive">
6767 <PLACE name="Germany"/>
6769 <CGENUS name="Aliwalia" incertae="1"/>
6770 <CGENUS name="Alwalkeria" incertae="1"/>
6771 <CGENUS name="Caseosaurus" incertae="1"/>
6772 <CGENUS name="Liassaurus" incertae="1" q="1"/>
6773 <CGENUS name="Merosaurus" incertae="1" q="1"/>
6774 <CLADE name="Herrerasauria">
6775 <MEANING><NOMEN name="Herrerasaurus"/>' <LOW>taxon</LOW></MEANING>
6776 <CSYNONYM q="1" name="Herreravia">
6777 <AUTHOR name="Paul" year="1988"/>
6779 <CLADE name="Herrerasauridae" in="Herrerasaurus, Staurikosaurus">
6780 <CSYNONYM q="1" name="Spondylosomatidae"/>
6781 <AUTHOR name="Benedetto" year="1973"/>
6782 <AUTHOR type="sensu" name="Novas" year="1992"/>
6785 <PLACE name="Brazil"/>
6786 <REMAINS content="pubis, ischium, dorsal & caudal vertebrae"/>
6788 <CGENUS name="Chindesaurus"/>
6789 <CLADE name="Staurikosaurinae" in="Staurikosaurus" out="Herrerasaurus">
6790 <CGENUS name="Staurikosaurus"/>
6792 <CLADE name="Herrerasaurinae" in="Herrerasaurus" out="Staurikosaurus">
6793 <AUTHOR type="implied" name="Benedetto" year="1973"/>
6794 <CGENUS name="Herrerasaurus"/>
6798 <CLADE name="Neotheropoda" in="Neornithes, Coelophysis" silhouette="neotheropoda">
6799 <MEANING>new theropods</MEANING>
6800 <AUTHOR name="Bakker" year="1986"/>
6801 <AUTHOR type="sensu" name="Sereno"/>
6803 <TIME section="late" value="Barremian"/>
6804 <PLACE name="China"/>
6806 <UNNAMED indet="1" comment="(dromaeosaurid?)">
6808 <PLACE name="Australia"/>
6809 <REMAINS content="partial humerus"/>
6812 <PLACE name="Brazil"/>
6813 <TIME value="Albian"/>
6815 <UNNAMED indet="1" q="1">
6816 <TIME value="Maastrichtian"/>
6817 <PLACE name="Australia"/>
6820 <TIME value="Albian"/>
6821 <PLACE name="Utah"/>
6824 <TIME value="Campanian"/>
6825 <TIME value="Maastrichtian"/>
6826 <PLACE name="New Zealand"/>
6829 <TIME value="Aptian"/>
6830 <PLACE name="Japan"/>
6831 <REMAINS content="neck vertebra"/>
6834 <TIME value="Barremian"/>
6835 <TIME value="Aptian"/>
6836 <PLACE name="Japan"/>
6837 <REMAINS content="teeth, vertebra"/>
6840 <TIME value="Coniacian"/>
6841 <TIME value="Santonian"/>
6842 <PLACE name="Japan"/>
6843 <REMAINS content="tibia"/>
6846 <TIME value="Valanginian"/>
6847 <PLACE name="Japan"/>
6848 <REMAINS content="teeth"/>
6851 <TIME value="Valanginian"/>
6852 <TIME value="Aptian"/>
6853 <PLACE name="Japan"/>
6854 <REMAINS content="teeth"/>
6857 <TIME value="K" q="1"/>
6858 <PLACE name="Japan"/>
6859 <REMAINS content="small teeth"/>
6861 <UNNAMED comment="giant, tall-spined">
6862 <TIME section="earliest" value="Oxfordian"/>
6863 <PLACE name="Germany"/>
6865 <UNNAMED comment="large">
6866 <TIME value="J" q="1"/>
6867 <PLACE name="China"/>
6870 <TIME value="J" q="1"/>
6871 <PLACE name="China"/>
6872 <REMAINS content="postcranium"/>
6875 <TIME value="Barremian"/>
6876 <PLACE name="England"/>
6879 <TIME value="Barremian"/>
6880 <PLACE name="China"/>
6883 <PLACE name="Alabama"/>
6885 <CGENUS name="Betasuchus" incertae="1"/>
6886 <CGENUS name="Capitalsaurus" incertae="1"/>
6887 <CGENUS name="Chuandongocoelurus" incertae="1"/>
6888 <CGENUS name="Coeluroides" incertae="1"/>
6889 <CGENUS name="Dinosaurus2" incertae="1" q="1"/>
6890 <CGENUS name="Elaphrosaurus gautieri" incertae="1"/>
6891 <CGENUS name="Elaphrosaurus iguidensis" incertae="1"/>
6892 <CGENUS name="Embasaurus" incertae="1"/>
6893 <CGENUS name="Halticosaurus" incertae="1"/>
6894 <CGENUS name="Inosaurus" incertae="1"/>
6895 <CGENUS name="Kagasaurus" incertae="1"/>
6896 <CGENUS name="Kelmayisaurus" incertae="1"/>
6897 <CGENUS incertae="1" name="Labocania"/>
6898 <CGENUS name="Megalosaurus chubutensis" incertae="1"/>
6899 <CGENUS name="Megalosaurus insignis" incertae="1"/>
6900 <CGENUS name="Megalosaurus pannoniensis" incertae="1"/>
6901 <CGENUS name="Megalosaurus pombali" incertae="1"/>
6902 <CGENUS name="Megalosaurus terquemi" incertae="1"/>
6903 <CGENUS name="Ngexisaurus" incertae="1"/>
6904 <CGENUS name="Ornithomimus affinis" incertae="1"/>
6905 <CGENUS name="Ozraptor" incertae="1"/>
6906 <CGENUS name="Patricosaurus" incertae="1"/>
6907 <CGENUS name="Podokesaurus" incertae="1"/>
6908 <CGENUS name="Poekilopleuron schmidti" incertae="1"/>
6909 <CGENUS name="Rapator" incertae="1"/>
6910 <CGENUS name="Sigilmassasaurus" incertae="1"/>
6911 <CGENUS name="Sinocoelurus" incertae="1" q="1"/>
6912 <CGENUS name="Tsuchikurasaurus" incertae="1"/>
6913 <CGENUS name="Tugulusaurus" incertae="1"/>
6914 <CGENUS name="Unquillosaurus" incertae="1"/>
6915 <CGENUS name="Wakinosaurus" incertae="1"/>
6916 <CGENUS name="Zupaysaurus" incertae="1"/>
6917 <CLADE name="Ceratosauria" in="Ceratosaurus" out="Neornithes">
6919 <NOMEN name="Ceratosaurus"/>' <LOW>taxon</LOW>
6921 <AUTHOR type="sensu" name="Gauthier" year="1984"/>
6922 <AUTHOR type="non" name="Sereno" year="1999"/>
6923 <CGENUS name="Elaphrosaurus" incertae="1"/>
6924 <CGENUS name="Pterospondylus" incertae="1" q="1"/>
6925 <CLINK name="Coelophysoidea"/>
6926 <CLINK name="Neoceratosauria"/>
6928 <CLINK name="Tetanurae"/>
6933 <CLADOGRAM alternate="1">
6934 <CLADE name="Neotheropoda">
6935 <CLADE name="Coelophysoidea"/>
6937 <CSYNONYM name="Neotheropoda" sensu="Bakker"/>
6938 <CLADE name="Ceratosauria" comment="same membership as Neoceratosauria in main cladogram"/>
6939 <CLADE name="Tetanurae"/>
6943 <CLADOGRAM alternate="1">
6944 <REFER page="Dinosauria"/>
6947 <P> Theropoda is an incredibly diverse group of <LINK
6948 content="dinosaurs"/>. Most of the Mesozoic theropods were sharp-toothed
6949 predators, although there have been a few toothless, possibly herbivorous
6950 groups. During the <LINK content="Jurassic"/> (or possibly <LINK
6951 content="Triassic"/>), some theropods evolved into feathered, flying
6952 forms. Their descendants are today's <LINK content="birds"/>. </P>
6954 <P header="An Odd Name"> The group Theropoda ("beast feet") was named early on in
6955 paleontological history, along with <LINK content="Ornithopoda"/> ("bird
6956 feet" - a major <LINK content="ornithischian"/> group). It almost seems as
6957 though the names were somehow mixed up and improperly assigned, since
6958 theropods have bird-like feet and ornithopods have somewhat more <LINK
6959 content="mammal"/>-like feet, but the names stuck and it's far too late to
6960 change them now. </P>
6962 <P header="Origin and Evolution"> The non-neotheropod genera shown above
6963 are often informally referred
6964 to as "herrerasaurs". "Herrerasaurs" may be basal theropods, as shown
6965 here, basal <LINK content="saurischians"/>, or even basal <LINK
6966 content="dinosauriforms"/>. They had many primitive features, such as five
6967 digits on the hands, although the outer two were very small and had no
6970 <P> <ILLO name="coelophysid_manus" caption="ceratosaurian manus"/> <ILLO
6971 name="dromaeosaurid_manus" caption="tetanuran manus"/> The more advanced
6972 theropods, or neotheropods, are divided into two groups. The ceratosaurs
6973 retained four digits on the hand (the outer one reduced), while the more
6974 advanced <LINK content="tetanurans"/> only have three. Ceratosaurs were
6975 further characterized by extra openings in cervical and dorsal centra,
6976 fused pelvic bones and tarsals (in adults), and some modifications of the
6977 tibia and fibula. </P>
6979 <P> It is possible that Ceratosauria as shown here is a paraphyletic group,
6980 characterized only by primitive features. Neoceratosaurs may be share more recent
6981 ancestry with tetanurans than with coelophysoids. </P>
6985 <TAXON name="Thyreophora" nickname="Armored Dinosaurs" silhouette="thyreophoroidea">
6986 <WORD key="1" content="armored, armoured, armor, armour, plated, plates, scuted, spikes, spiked, defense, tank"/>
6987 <WORD essay="1" content="armored tanks"/>
6989 <CLADE name="Thyreophora" in="Ankylosaurus" out="Triceratops" silhouette="thyreophora">
6990 <CGENUS name="Scutellosaurus"/>
6991 <CLADE name="Thyreophoroidea" in="Ankylosaurus" out="Scutellosaurus" silhouette="thyreophoroidea">
6995 <CSYNONYM name="Enoplosauria" q="1"/>
6996 <CGENUS name="Lusitanosaurus" incertae="1"/>
6997 <CGENUS name="Tatisaurus" incertae="1"/>
6998 <CGENUS name="Emausaurus"/>
7000 <CGENUS name="Scelidosaurus"/>
7001 <CLADE name="Eurypoda" in="Ankylosaurus, Stegosaurus">
7002 <CGENUS name="Brachypodosaurus" incertae="1"/>
7005 <PLACE name="Argentina"/>
7007 <CLINK name="Stegosauria"/>
7008 <CLINK name="Ankylosauria"/>
7014 <CLADOGRAM alternate="1">
7015 <REFER page="Ornithischia"/>
7018 <P> Thyreophora includes the "armored <LINK content="dinosaurs"/>", a
7019 group of primarily quadrupedal <LINK content="ornithischians"/> with bony
7020 plates, scutes, and/or spikes protecting their backs from theropod
7021 predators. Some <LINK content="titanosaurian"/> <LINK content="sauropods"/>
7022 also exhibited armor like this. </P>
7024 <P header="Origin and Evolution"> <NOMEN name="Scutellosaurus"/> was
7025 once classified as a <LINK
7026 content="fabrosaurid"/>, but it is really the earliest and most primitive
7027 known member of this clade of armored dinosaurs. It was small, like
7028 "fabrosaurids", but more robust and with bony scutes as armor. </P>
7030 <P> The more advanced thyreophorans, like <NOMEN name="Scelidosaurus"/>, were
7031 larger and fully quadrupedal. Creatures like this are thought to have
7032 given rise to the two major lineages of thyreophorans, the plated <LINK
7033 content="stegosaurs"/> and the heavily armored <LINK
7034 content="ankylosaurs"/>.</P>
7038 <TAXON name="Titanosauria" nickname="Armored Sauropods - The Largest of the Large">
7039 <WORD key="1" content="big, huge, large, giant, long, armored, armor, armoured, armour, titan, titanic, gigantic, largest, biggest"/>
7040 <WORD essay="1" content="titanosaurian"/>
7042 <CLADE name="Titanosauria" in="Titanosaurus" out="Brachiosaurus, Euhelopus" silhouette="titanosauria">
7044 <NOMEN name="Titanosaurus"/>' <LOW>taxon</LOW>
7046 <AUTHOR type="sensu" name="Wilson, Sereno" year="1998"/>
7049 <PLACE name="Brazil"/>
7050 <REMAINS content="osteoderm"/>
7054 <PLACE name="Mongolia"/>
7055 <REMAINS content="postcranium"/>
7058 <PLACE name="Utah"/>
7059 <REMAINS content="vertebrae, braincase, etc."/>
7061 <UNNAMED cf="Aegyptosaurus">
7062 <TIME value="Albian"/>
7063 <TIME value="Cenomanian" section="early"/>
7064 <PLACE name="Africa"/>
7066 <UNNAMED cf="Alamosaurus" comment="large">
7067 <PLACE name="Texas"/>
7068 <TIME value="Maastrichtian"/>
7069 <REMAINS content="12 cervical vertebrae"/>
7071 <UNNAMED comment="giant">
7072 <PLACE name="Argentina"/>
7073 <TIME value="Albian"/>
7074 <TIME value="Cenomanian"/>
7075 <!-- LENGTH value="51"/ -->
7076 <REMAINS content="cervical vertebrae, femur, etc."/>
7078 <CGENUS name="Aegyptosaurus" incertae="1"/>
7079 <CGENUS name="Aepisaurus" incertae="1" q="1"/>
7080 <CGENUS name="Alamosaurus" incertae="1"/>
7081 <CGENUS name="Algoasaurus" incertae="1"/>
7082 <CGENUS name="Bruhathkayosaurus" incertae="1" q="1"/>
7083 <CGENUS name="Campylodoniscus" incertae="1"/>
7084 <CGENUS name="Clasmodosaurus" incertae="1" q="1"/>
7085 <CGENUS name="Iuticosaurus" incertae="1" q="1"/>
7086 <CGENUS name="Chubutisaurus"/>
7087 <CGENUS name="Pleurocoelus sp." q="1"/>
7089 <CGENUS name="Macrurosaurus" q="1"/>
7090 <CGENUS name="Tangvayosaurus" q="1"/>
7091 <CLADE name="Huabeisauridae" q="1" incertae="1">
7092 <CGENUS name="Huabeisaurus"/>
7094 <CLADE name="Nemegtosauridae" q="1" incertae="1">
7095 <CGENUS name="Nemegtosaurus"/>
7096 <CGENUS name="Phuwiangosaurus" q="1"/>
7097 <CGENUS name="Quaesitosaurus"/>
7101 <PLACE name="Argentina"/>
7102 <REMAINS content="skull"/>
7104 <CGENUS name="Andesaurus"/>
7105 <CLADE in="Epachthosaurus, Saltasaurus, Argyrosaurus, Lirainosaurus">
7106 <CSYNONYM name="Titanosauria" sensu="Sanz, J. Powell, Le Loeuff, Martinez, Pereda-Suberbiola" year="1999"/>
7107 <CGENUS name="Ampelosaurus" incertae="1"/>
7108 <CGENUS name="Hypselosaurus" incertae="1"/>
7109 <CGENUS name="Jainosaurus" incertae="1"/>
7110 <CGENUS name="Magyarosaurus" incertae="1"/>
7111 <CLADE name="Pellegrinisauridae" incertae="1">
7112 <AUTHOR type="implied" name="Salgado" year="1996"/>
7113 <CGENUS name="Pellegrinisaurus"/>
7115 <CGENUS name="Titanosaurus" incertae="1"/>
7116 <CGENUS name="Epachthosaurus"/>
7117 <CGENUS name="Janenschia"/>
7118 <CGENUS name="Malawisaurus"/>
7119 <CLADE in="Saltasaurus, Argyrosaurus, Lirainosaurus">
7120 <CSYNONYM q="1" name="Eutitanosauria">
7121 <AUTHOR name="Sanz, J. Powell, Le Loeuff, Martinez, Pereda-Suberbiola" year="1999"/>
7123 <CLADE incertae="1">
7124 <CGENUS name="Lirainosaurus"/>
7125 <UNNAMED comment="Peiropolis">
7126 <PLACE name="Brazil"/>
7129 <CGENUS incertae="1" name="Argentinosaurus"/>
7131 <CGENUS name="Antarctosaurus" q="1"/>
7132 <CGENUS name="Laplatasaurus"/>
7134 <CGENUS name="Argyrosaurus"/>
7137 <CGENUS name="Aeolosaurus"/>
7138 <CGENUS name="Gondwanatitan" q="1"/>
7140 <CLADE name="Saltasauridae" in="Saltasaurus, Opisthocoelicaudia">
7141 <CLADE name="Opisthocoelicaudinae" in="Opisthocoelicaudia" out="Saltasaurus">
7142 <CSYNONYM name="Nemegtosaurinae" q="1"/>
7143 <CGENUS name="Opisthocoelicaudia"/>
7145 <CLADE name="Saltasaurinae" out="Opisthocoelicaudia" in="Saltasaurus">
7146 <CGENUS name="Neuquensaurus"/>
7147 <CGENUS name="Saltasaurus"/>
7159 <CLADOGRAM alternate="1">
7160 <CLADE name="Titanosauroidea" sensu="Sanz, J. Powell, Le Loeuff, Martinez, Pereda-Suberbiola" year="1999">
7161 <CGENUS name="Opisthocoelicaudia"/>
7162 <CLADE name="Titanosauria" sensu="Sanz, J. Powell, Le Loeuff, Martinez, Pereda-Suberbiola" year="1999" in="Epachthosaurus, Saltasaurus, Argyrosaurus, Lirainosaurus">
7163 <CGENUS name="Epachthosaurus"/>
7164 <CLADE name="Eutitanosauria">
7166 <CGENUS name="Saltasaurus"/>
7167 <CGENUS name="Argyrosaurus"/>
7170 <CGENUS name="Lirainosaurus"/>
7171 <UNNAMED comment="Peiropolis"/>
7177 <CLADOGRAM alternate="1">
7178 <REFER page="Macronaria"/>
7181 <P> These primarily Cretaceous animals represent the last group of <LINK
7182 content="sauropods"/> before the great K/T extinction. Bony plates have
7183 been found with some specimens, indicating that they were armored, like
7184 <LINK content="ankylosaurs"/>. </P>
7186 <P header="True Titans"> South American forms such as <NOMEN name="Argentinosaurus"/> were some
7187 of the largest land animals of all time, probably larger than the gigantic
7188 <LINK content="brachiosaurids"/> of the <LINK content="Jurassic"/>.
7189 <NOMEN name="Argentinosaurus"/> has been estimated at 80-100 metric
7190 tonnes. Others, like <NOMEN name="Andesaurus"/>, <NOMEN
7191 name="Antarctosaurus"/>, and <NOMEN name="Argyrosaurus"/>, may have been
7192 of similar size. </P>
7194 <P header="Humble Beginnings"> Argentinian egg material has been attributed to titanosaurs. The eggs are
7195 typically 11-12cm in diameter, some up to 17cm. From relatively
7196 small eggs like these came creatures which would grow thousands of times
7197 larger! Eggs have also been attributed to <NOMEN name="Hypselosaurus"/>, a
7198 European titanosaur. Recently, Argentinian titanosaur eggs containing
7199 fossilized embryos with skin impressions were discovered. The impressions
7200 show non-overlapping scales, like those seen in many other
7201 <LINK content="dinosaur"/> skin impressions. </P>
7205 <TAXON name="Troodontidae" nickname="Brainy, Big-Eyed Dinos">
7206 <WORD key="1" content="dinosauroid, brainy, brain, smart, intelligent, intelligence, e.q., nocturnal, sickle, claw, switchblade"/>
7207 <WORD essay="1" content="night prowlers"/>
7209 <CLADE name="Troodontidae" in="Troodon" out="Deinonychus, Neornithes, Ornithomimus, Oviraptor, Therizinosaurus, Tyrannosaurus" silhouette="troodontidae">
7210 <AUTHOR name="Gilmore" year="1924"/>
7211 <AUTHOR type="sensu" name="Varricchio" year="1997"/>
7212 <AUTHOR type="emended" name="herein"/>
7213 <CSYNONYM name="Saurornithoididae"/>
7214 <CSYNONYM name="Troödontidae"/>
7215 <CSYNONYM name="Ornithodesmidae" q="1"/>
7218 <PLACE name="Mongolia"/>
7221 <TIME value="Albian"/>
7222 <PLACE name="Utah"/>
7225 <TIME value="Aptian"/>
7226 <TIME value="Albian"/>
7227 <PLACE name="Mongolia"/>
7229 <CGENUS name="Sinornithoides"/>
7231 <CGENUS name="Borogovia" incertae="1"/>
7232 <CGENUS name="Tochisaurus" incertae="1"/>
7233 <CGENUS name="Byronosaurus"/>
7235 <CGENUS name="Saurornithoides"/>
7236 <CGENUS name="Troodon"/>
7242 <P>The phylogeny above is somewhat tentative.</P>
7243 <P header="Intelligence and Niche"> Troodontids (formerly known as
7244 saurornithoidids) were remarkable in
7245 having the largest E.Q. (encephalization quotient) of all non-<LINK
7246 content="avialan"/> <LINK content="dinosaurs"/>. Intelligence-wise, they may
7247 have been on level with some modern-day <LINK content="birds"/>. The large
7248 brain, huge eyes, and grasping hands of these <LINK content="theropods"/>
7249 may indicate a nocturnal, predatory lifestyle. However, their teeth may
7250 indicate omnivory. </P>
7252 <P header="Feet of Death"> The feet were equipped with "switchblade claws", similar to those of
7253 <LINK content="dromaeosaurids"/>. They were once placed with the
7254 dromaeosaurids in <LINK content="Deinonychosauria"/>, but this grouping
7255 has been questioned. They share some features with <LINK
7256 content="ornithomimosaurs"/>, such as a pinched middle metatarsal
7257 (possibly a speed adaptation), features of the braincase, and large eyes.
7258 They have also been placed in basal <LINK content="Paraves"/>, basal <LINK
7259 content="Avialae"/>, and as sister group of the <LINK
7260 content="oviraptorosaur"/>-<LINK content="therizinosaur"/> group. </P>
7264 <TAXON name="Tyrannosauroidea" nickname="Tyrant Kings of the Dinosaurs">
7265 <WORD key="1" content="t-rex, rex, tyrant, trex"/>
7266 <WORD essay="1" content="gigantic predators, tyrannosaur, tyrannosaurs"/>
7268 <CLADE name="Tyrannosauroidea" in="Tyrannosaurus" out="Ornithomimus, Neornithes" silhouette="tyrannosauroidea">
7269 <CSYNONYM name="Tyrannosauria"/>
7270 <CSYNONYM name="Deinodontoidea"/>
7272 <REMAINS content="premaxillary tooth"/>
7273 <PLACE name="Japan"/>
7276 <CGENUS name="Futabasaurus" incertae="1" q="1"/>
7277 <CGENUS name="Iliosuchus" q="1"/>
7278 <CGENUS name="Itemirus" q="1"/>
7279 <CGENUS name="Siamotyrannus" q="1"/>
7280 <CGENUS name="Stokesosaurus" q="1"/>
7281 <CGENUS name="Tonouchisaurus" q="1"/>
7282 <CLADE name="Tyrannosauridae">
7283 <CSYNONYM name="Deinodontidae"/>
7284 <UNNAMED indet="1" comment="gracile">
7285 <TIME section="middle-late" value="Campanian"/>
7286 <PLACE name="Alberta"/>
7288 <CGENUS name="Aublysodon" incertae="1"/>
7289 <CGENUS name="Alectrosaurus"/>
7290 <CGENUS name="Shanshanosaurus"/>
7291 <CGENUS name="Stygivenator"/>
7292 <CLADE name="Tyrannosaurinae" in="Tyrannosaurus" out="Alectrosaurus, Aublysodon">
7293 <CSYNONYM name="Deinodontinae"/>
7294 <CGENUS name="Deinodon" incertae="1"/>
7295 <CGENUS name="Alioramus" silhouette="alioramus"/>
7297 <CGENUS name="Albertosaurus"/>
7298 <CGENUS name="Gorgosaurus"/>
7299 <CLADE name="Tyrannosaurini" in="Tyrannosaurus" out="Albertosaurus, Gorgosaurus">
7300 <CGENUS name="Daspletosaurus"/>
7301 <CGENUS name="Tyrannosaurus"/>
7308 <CLADOGRAM alternate="1">
7309 <CLADE name="Tyrannosauridae">
7310 <CGENUS name="Alectrosaurus"/>
7311 <CLADE name="Tyrannosaurinae"/>
7312 <CLADE name="Aublysodontinae">
7313 <CSYNONYM name="Shanshanosaurinae"/>
7314 <CGENUS name="Aublysodon" incertae="1"/>
7315 <CGENUS name="Shanshanosaurus"/>
7316 <CGENUS name="Stygivenator"/>
7321 <P> This was the last group of huge predatory
7322 <LINK content="dinosaurs"/>, including the
7323 ever-popular <NOMEN name="Tyrannosaurus rex"/> ("king of the tyrant
7324 lizards"), a 40+ foot-long monster, largest of all land predators,
7325 excluding some <LINK content="carcharodontosaurine allosaurids"/>. </P>
7327 <P> For all their size and strength, tyrannosaurids had remarkably small arms
7328 with only two fingers on the hand, the third digit having degenerated to
7329 near nothingness. </P>
7331 <P header="Fast Predators or Slow Scavengers?"> The near lack of forelimbs in tyrannosaurids (and to a lesser extent in
7332 some other large predatory dinosaurs) poses an interesting problem: How
7333 did they deal with tripping? A recent study of <NOMEN
7334 name="Tyrannosaurus rex"/> which incorporated data from studies of fall
7335 trauma suggests that if <NOMEN name="T. rex"/> were to trip while running
7336 at top speed, the force of its fall would crush it. Therefore, it may be
7337 that <NOMEN name="T. rex"/> and other large tyrannosaurids restrained
7338 themselves to a more conservative speed. </P>
7340 <P> There have been some proposals that <NOMEN name="Tyrannosaurus"/> and
7341 perhaps other large tyrannosaurines were scavengers rather than predators,
7342 since they had such tiny arms and couldn't run at top speed. But in
7343 today's world there are no such things as true terrestrial scavengers
7344 (vultures are aerial, not terrestrial, and can cover much more ground with
7345 much less effort). All other terrestrial animals that eat carrion will
7346 also hunt for their prey. It is likely that <NOMEN name="Tyrannosaurus"/>
7347 fell into this category -- a hunter who wouldn't pass up an opportunity
7348 for a "free meal". Its huge head, muscular neck, and dagger-like teeth
7349 would easily have made up for its tiny arms, and its main prey, <LINK
7350 content="duck-billed dinosaurs"/>, probably had similar problems in
7351 running at top speed, as they also had small forearms (albeit not nearly
7352 as small as tyrannosaurid forearms) and large body size. Large
7353 tyrannosaurines could almost certainly run faster than any animal of their
7354 size. Their legs were similar to those of their close relatives the <LINK
7355 content="ornithomimosaurs"/> (a.k.a. "ostrich mimics"), often considered
7356 the fastest (running) dinosaurs of all. </P>
7360 <TAXON name="Vertebrata" nickname="Animals with Backbones" simple="1">
7361 <WORD key="1" essay="1" content="fish"/>
7362 <WORD essay="1" content="ray"/>
7363 <INCLUDED content="Carcharias, Cladoselaches, Dunkleosteus, Leedsichthys, Lepidotes, Longania, Squatina, Stethacanthus"/>
7365 <CLADE name="Vertebrata" silhouette="vertebrata">
7369 <CLADE name="Hyperoartia" q="1" extinct="1"/>
7370 <CLADE name="Conodontia" q="1" extinct="1"/>
7371 <CLADE name="Pteraspidomorphi" content="lampreys, etc.">
7372 <CSYNONYM name="Diplorhina"/>
7374 <CLADE name="Thelodonti" extinct="1" q="1"/>
7376 <CLADE name="Anaspida" extinct="1" q="1"/>
7378 <CLADE name="Galeaspida" extinct="1"/>
7380 <CLADE name="Pituriaspida" q="1" extinct="1"/>
7381 <CLADE name="Osteostraci" extinct="1"/>
7382 <CLADE name="Gnathostomata" content="animals with jaws">
7386 <CLADE name="Placodermi" content="certain armored fish" extinct="1"/>
7387 <CLADE name="Chondrichthyes" content="sharks, rays, ratfish">
7392 <CLADE name="Teleostomi" content="animals with bony skeletons">
7393 <CLADE name="Acanthodii" content='spiny "sharks"' extinct="1"/>
7394 <CLADE name="Osteichthyes">
7398 <CSYNONYM name="Euteleostomi"/>
7399 <CSYNONYM name="Neoteleostomi"/>
7400 <CGENUS name="Psarolepis" q="1" extinct="1"/>
7401 <CLADE name="Lophosteiformes" q="1" extinct="1">
7402 <CLADE name="Actinopterygii" content="ray-finned fish">
7407 <CLADE name="Sarcopterygii" content="vertebrates with fleshy limbs">
7411 <CLADE name="Onychodontiformes" q="1" extinct="1">
7412 <CSYNONYM name="Sturniiformes"/>
7415 <CLADE name="Coelacanthomorpha" content="coelacanths, etc.">
7416 <CSYNONYM name="Actinistia"/>
7418 <CLADE name="Rhipidistia" status="informal">
7419 <CLADE name="Dipnomorpha">
7420 <CLADE name="Dipnoi" content="lungfish"/>
7421 <CLADE name="Porolepiformes" extinct="1"/>
7423 <CLADE name="Tetrapodomorpha">
7424 <CGENUS name="Kenichthys" extinct="1"/>
7426 <CLADE name="Rhizodontida" extinct="1"/>
7427 <CLADE name="Osteolepimorpha" status="informal">
7428 <CSYNONYM name="Choanata" q="1"/>
7429 <CLADE name="Osteolepididae" q="1"/>
7431 <CLADE name="Megalichthyidae" extinct="1"/>
7433 <CGENUS name="Medoevia" extinct="1"/>
7435 <CLADE name="Canowindridae" extinct="1"/>
7437 <CGENUS name="Gryptoptychius" extinct="1"/>
7439 <CLADE name="Thristicopteridae" extinct="1">
7440 <CSYNONYM name="Eusthenopteridae"/>
7442 <CLADE name="Elpistostegalia">
7443 <CSYNONYM name="Panderichthyida"/>
7444 <CGENUS name="Elpistostega" extinct="1"/>
7445 <CGENUS name="Panderichthys" extinct="1"/>
7446 <CLINK name="Tetrapoda"/>
7470 Within the group of animals that have backbones,
7471 <LINK content="dinosaurs"/> belong to the tetrapods, or terrestrial
projects / idzebra-moved-to-github.git / blob