| archosaur | (n) extinct reptiles including: dinosaurs; plesiosaurs; pterosaurs; ichthyosaurs; thecodonts, Syn. archosaurian, archosaurian reptile |
| archosauria | (n) a large subclass of diapsid reptiles including: crocodiles; alligators; dinosaurs; pterosaurs; plesiosaurs; ichthyosaurs; thecodonts, Syn. subclass Archosauria |
| archosaurian | (adj) of or relating to reptiles of the subclass Archosauria |