†Suborder Sauropodomorpha †Thecodontosaurus †Family Plateosauridae †Riojasaurus †Family Massospondylidae †Infraorder Sauropoda †Family Vulcanodontidae †Family Omeisauridae †Division Neosauropoda †Family Cetiosauridae †Family Diplodocidae †Subdivision Macronaria †Family Camarasauridae †Infradivision Titanosauriformes †Family Brachiosauridae †Cohort Somphospondyli †Family Euhelopodidae †Family Titanosauridae †Order Ornithischia †Family Pisanosauridae †Family Fabrosauridae †Suborder Thyreophora †Family Scelidosauridae †Infraorder Stegosauria †Infraorder Ankylosauria †Family Nodosauridae †Family Ankylosauridae †Suborder Cerapoda †Infraorder Pachycephalosauria †Infraorder Ceratopsia †Family Psittacosauridae †Family Protoceratopsidae †Family Ceratopsidae †Infraorder Ornithopoda †Family Heterodontosauridae †Family Hypsilophodontidae †Family Iguanodontidae * †Family Hadrosauridae Weishampel/Dodson/Osmólska classification The following is based on the second edition of The Dinosauria, a compilation of articles by experts in the field that provided the most comprehensive coverage of Dinosauria available when it was first published in 1990. The second edition updates and revises that work. The cladogram and phylogenetic definitions below reflect the current understanding of evolutionary relationships. The taxa and symbols in parentheses after a given taxa define these relationships. The plus symbol ("+") between taxa indicates the given taxa is a node-based clade, defined as comprising all descendants of the last common ancestor of the "added" taxa. The greater-than symbol (">") indicates the given taxon is a stem-based taxon, comprising all organisms sharing a common ancestor that is not also an ancestor of the "lesser" taxon. Saurischia (Triceratops/Stegosaurus) Herrerasauria (Herrerasaurus > Liliensternus, Plateosaurus) Herrerasauridae (Herrerasaurus + Staurikosaurus) ? Eoraptor lunensis Sauropodomorpha (Saltasaurus > Theropoda) ? Saturnalia tupiniquim ? Thecodontosauridae Prosauropoda (Plateosaurus > Sauropoda) ? Thecodontosauridae ? Anchisauria (Anchisaurus + Melanorosaurus) ? Anchisauridae (Anchisaurus > Melanorosaurus) ? Melanorosauridae (Melanorosaurus > Anchisaurus) Plateosauria (Jingshanosaurus + Plateosaurus) Massospondylidae Yunnanosauridae Plateosauridae (Plateosaurus > Yunnanosaurus, Massospondylus) Sauropoda (Saltasaurus > Plateosaurus) ? Anchisauridae ? Melanorosauridae Blikanasauridae Vulcanodontidae Eusauropoda (Shunosaurus + Saltasaurus) ? Euhelopodidae Mamenchisauridae Cetiosauridae (Cetiosaurus > Saltasaurus) Neosauropoda (Diplodocus + Saltasaurus) Diplodocoidea (Diplodocus > Saltasaurus) Rebbachisauridae (Rebbachisaurus > Diplodocus) Flagellicaudata Dicraeosauridae (Dicraeosaurus > Diplodocus) Diplodocidae (Diplodocus > Dicraeosaurus, Apatosaurus) Macronaria (Saltasaurus > Diplodocus) ? Jobaria tiguidensis Camarasauromorpha (Camarasaurus + Saltasaurus) Camarasauridae Titanosauriformes (Brachiosaurus + Saltasaurus) Brachiosauridae (Brachiosaurus > Saltasaurus) Titanosauria (Saltasaurus > Brachiosaurus) Andesauridae Lithostrotia (Malawisaurus + Saltasaurus) Isisaurus colberti Paralititan stromeri Nemegtosauridae Saltasauridae (Opisthocoelicaudia + Saltasaurus) Theropoda (Passer domesticus > Cetiosaurus oxoniensis) ? Eoraptor lunensis ? Herrerasauridae Ceratosauria (Ceratosaurus nasicornis > Aves) ? Coelophysoidea (Coelophysis > Ceratosaurus) ? Dilophosaurus wetherilli Coelophysidae (Coelophysis + Megapnosaurus) ? Neoceratosauria (Ceratosaurus > Coelophysis) Ceratosauridae Abelisauroidea (Carnotaurus sastrei > C. nasicornis) Abelisauria (Noasaurus + Carnotaurus) Noasauridae Abelisauridae (Abelisaurus comahuensis + C. sastrei) Carnotaurinae (Carnotaurus > Abelisaurus) Abelisaurinae (Abelisaurus > Carnotaurus) Tetanurae