class Aves vs Archaeornithes

class Aves and Archaeornithes both are nouns.

Word	Noun	Adjective	Verb	Adverb
class Aves	Yes	No	No	No
Archaeornithes	Yes	No	No	No

class Aves (noun)	Archaeornithes (noun)
(ornithology) the class of birds	primitive reptile-like fossil birds of the Jurassic or early Cretaceous