Dictionary
ar•cho•saur
Pronunciation: (är'ku-sôr"), [key]—
n.
any reptile of the subclass Archosauria, including the dinosaurs, pterosaurs, and crocodilians and characterized by two pairs of openings in the temporal region of the skull.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.