Source : Webster's Revised Unabridged Dictionary (1913)

Pterosaur \Pter"o*saur\, n. [Gr. ? wind + ? a lizard.] (Paleon.)
   A pterodactyl.

Source : WordNet®

pterosaur
     n : extinct flying reptile of the Jurassic and Cretaceous having
         a birdlike beak and membranous wings supported by the
         very long fourth digit of each forelimb [syn: {flying
         reptile}]