subphylum Vertebrata vs bird family

subphylum Vertebrata and bird family both are nouns.

Word	Noun	Adjective	Verb	Adverb
subphylum Vertebrata	Yes	No	No	No
bird family	Yes	No	No	No

subphylum Vertebrata (noun)	bird family (noun)
fishes, amphibians, reptiles, birds, mammals	a family of warm-blooded egg-laying vertebrates characterized by feathers and forelimbs modified as wings