Dinosauria The MRCA of Saurischia and Ornithischia, and its descendants *** Eoraptor The most basal known dinosaur Saurischia Everything closer to Megalosaurus than to Iguanodon Sauropodomorpha Sauropods and their ancestors and close relatives Brontosauria Plateosauria Massospondylidae Yunnanosaurinae *** Yunnanosaurus Sauropoda Huge, long-necked herbivores Eusauropoda *** Jobaria A surprisingly primitive Early Cretaceous form Neosauropoda Diplodocimorpha Diplodocus, Apatosaurus, Seismosaurus and kin Rebbachisauridae Rebbachisaurinae *** Rebbachisaurus Had a sail on its back Macronaria Camarasauromorpha Titanosauriformes Brachiosauridae *** Sauroposeidon The tallest known dinosaur (18m) Titanosauria Eutitanosauria *** Argentinosaurus The heaviest known dinosaur (100 tonnes) Theropoda Bipedal carnivores Neotheropoda Ceratosauria May be polyphyletic if neoceratosaurs are tenanuran Coelophysoidea Coelophysidae Coelophysinae *** Dilophosaurus Had a pair of long crests on its nose Neoceratosauria *** Xenotarsosaurus Tetanurae Spinosauria Large carnivores with sails on their backs Spinosauridae Spinosaurinae Irritatorini *** Irritator Avetheropoda aka. Neotetanurae Carnosauria Previously used just to mean "large theropods" *** Fukuiraptor Allosauroidea Allosauridae Carcharodontosaurinae Some consider these animals derived abelisaurs *** Giganotosaurus Probably the heaviest known theropod Coelurosauria Previously used just to mean "small theropods" Maniraptoriformes [unnamed] Unnamed clade {Ornithomimosauria+Tyrannosauria} Arctometatarsalia Ornithomimosauria *** Harpymimus Tyrannosauroidea Includes early form Eotyrannus Tyrannosauridae Tyrannosaurinae Tyrannosaurini Could be defined as {Tyrannosaurs+Tarbosaurus} *** Tyrannosaurus Maniraptora Oviraptorosauria Includes Caenagnathidae Oviraptoridae *** Oviraptor Some specimens found brooding their nests Therizinosauria Truly freaky long-necked, huge-clawed fatsos Therizinosauroidea Therizinosauridae *** Nanshiungosaurus Paraves Eumaniraptora Deinonychosauria Troodontidae Highest encephalisation quotient on known dinos *** Byronosaurus Dromaeosauridae Velociraptorinae *** Velociraptor Much smaller in real life than in Jurassic Park Avialae Aves Birds, including modern birds Metornithes Alvarezsauria Short, stong args; long, gracile legs. Weird Alvarezsauridae Mononykinae Hands had only a single, spike-like finger *** Parvicursor Ornithischia Everything closer to Iguanodon than to Megalosaurus Genasauria Thyreophora The armoured dinosaurs, ankylosaurs and stegosaurs Thyreophoroidea Eurypoda Stegosauria Single or double row of plates down the back Stegosauridae *** Kentrosaurus Had spikes on its back instead of plates Ankylosauria Heavily armoured, above and below *** Minmi Cerapoda Defined as {Triceratops+Iguanodon} Marginocephalia Defined as {Triceratops+Pachycephalosaurus} Ceratopsia Neoceratopsia Everything closer to Triceratops than to Psittacosaurus *** Udanoceratops Coronosauria Ceratopsoidea Ceratopsomorpha Ceratopsidae {Chasmosaurinae+Centrosaurinae} *** Zuniceratops Pachycephalosauria Thick-headed, wide-bodied herbivorous bipeds *** Wannanosaurus Ornithopoda The least interesting of all the dinosaur groups *** Qantassaurus A profoundly dull basal ornithopod Euornithopoda Iguanodontia Euiguanodontia Dryomorpha Ankylopollexia Styracosterna *** Lurdosaurus Looks a lot like a fat Iguanodon Iguanodontoidea Hadrosauroidea Hadrosauridae Euhadrosauria Lambeosaurs (crested) + Hadrosaurs (not) Lambeosaurinae The least dull of all the ornithopods Lambeosaurini *** Corythosaurus