genus Erethizon vs mammal genus

genus Erethizon and mammal genus both are nouns.

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

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

genus Erethizon (noun)	mammal genus (noun)
a genus of Erethizontidae	a genus of mammals