genus Cavia vs mammal genus

genus Cavia and mammal genus both are nouns.

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

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

genus Cavia (noun)	mammal genus (noun)
type genus of the Caviidae: guinea pigs	a genus of mammals