genus Pteropus vs mammal genus

genus Pteropus and mammal genus both are nouns.

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

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

genus Pteropus: a genus of Megachiroptera, comprising some of the flying foxes (Pteropus)
mammal genus: a genus of mammals

genus Pteropus (noun)	mammal genus (noun)
a genus of Megachiroptera, comprising some of the flying foxes (Pteropus)	a genus of mammals