Reithrodontomys vs mammal genus

Reithrodontomys and mammal genus both are nouns.

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

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

Reithrodontomys (noun)	mammal genus (noun)
New World harvest mice	a genus of mammals