extinct reptiles including: dinosaurs; plesiosaurs; pterosaurs; ichthyosaurs; thecodonts

An archosaur is any member of the superorder Archosauria - a taxonomic grouping which includes the dinosaurs, pterosaurs, modern birds and, of course, the crocodylia.

'Ruling Reptile'. The group of animals that included dinosaurs, crocodiles, birds, and pterosaurs