genus Dromaius vs bird genus

genus Dromaius and bird genus both are nouns.

Word	Noun	Adjective	Verb	Adverb
genus Dromaius	Yes	No	No	No
bird genus	Yes	No	No	No

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

genus Dromaius (noun)	bird genus (noun)
a genus of birds in the order Casuariiformes	a genus of birds