genus Bison vs mammal genus

genus Bison and mammal genus both are nouns.

Word	Noun	Adjective	Verb	Adverb
genus Bison	Yes	No	No	No
mammal genus	Yes	No	No	No

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

genus Bison (noun)	mammal genus (noun)
sometimes considered a subgenus of genus Bos: American buffalo	a genus of mammals