Extinct flying reptile (11)
I believe the answer is:
pterodactyl
'extinct flying reptile' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for pterodactyl that I've seen before include "Flying dinosaur" , "Winged reptile of old" , "old flying reptile" , "Flying creature" , "reptile from the past" .)