genus Sinornis vs bird genus

genus Sinornis and bird genus both are nouns.

Word	Noun	Adjective	Verb	Adverb
genus Sinornis	Yes	No	No	No
bird genus	Yes	No	No	No

As nouns, bird genus is a hypernym of genus Sinornis; that is, bird genus is a word with a broader meaning than genus Sinornis:

genus Sinornis (noun)	bird genus (noun)
a genus of enantiornithine birds, now extinct (Sinornis)	a genus of birds