genus Cervus vs mammal genus

genus Cervus and mammal genus both are nouns.

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

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

genus Cervus (noun)	mammal genus (noun)
the type genus of the Cervidae	a genus of mammals