Main Entry: ptero·saur

Pronunciation: \ˈter-ə-ˌsȯr\

Function: noun

Etymology: New Latin Pterosauria, from Greek pteron wing + sauros lizard

Date: 1862

: any of an order (Pterosauria) of extinct flying reptiles existing from the Late Triassic throughout the Jurassic and most of the Cretaceous and having a featherless wing membrane extending from the side of the body along the arm to the end of the greatly elongated fourth digit