flying reptile vs pterosaur

flying reptile and pterosaur both are nouns.

Word	Noun	Adjective	Verb	Adverb
flying reptile	Yes	No	No	No
pterosaur	Yes	No	No	No

As nouns, flying reptile and pterosaur are synonyms defined as:

flying reptile and pterosaur: an extinct reptile of the Jurassic and Cretaceous having a bird-like beak and membranous wings supported by the very long fourth digit of each forelimb

flying reptile (noun)	pterosaur (noun)
an extinct reptile of the Jurassic and Cretaceous having a bird-like beak and membranous wings supported by the very long fourth digit of each forelimb	an extinct reptile of the Jurassic and Cretaceous having a bird-like beak and membranous wings supported by the very long fourth digit of each forelimb