Lepidosaur vs. Archosaur

Lepidosaurnoun

(zoology) A member of the Lepidosauria, reptiles with overlapping scales

Archosaurnoun

A reptile of the taxon Archosauria, which includes the extinct dinosaurs, plesiosaurs, pterosaurs and ichthyosaurs and modern crocodiles and birds.

Archosaurnoun

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

Archosaur

Archosauria (lit. 'ruling reptiles') is a clade of diapsids, with birds and crocodilians as the only living representatives. Archosaurs are broadly classified as reptiles, in the cladistic sense of term which includes birds.