class Aves vs Dinornithiformes

class Aves and Dinornithiformes both are nouns.

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

class Aves (noun)	Dinornithiformes (noun)
(ornithology) the class of birds	a ratite bird order: recently extinct flightless birds of New Zealand