any of an order (Saurischia) of dinosaurs with, typically, a pelvic structure similar to that of modern reptiles, including the theropods and sauropods
adjective
of the saurischians
See saurischian in American Heritage Dictionary 4
(sô-rĭsˈkē-ən)
noun
A dinosaur of the order Saurischia, having a pelvic girdle similar to that of modern reptiles.