mammal genus vs genus

mammal genus and genus both are nouns.

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

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

mammal genus (noun)	genus (noun)
a genus of mammals	a general kind of something
	(biology) taxonomic group containing one or more species