genus Phaethon vs bird genus

genus Phaethon and bird genus both are nouns.

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

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

genus Phaethon (noun)	bird genus (noun)
type genus of the Phaethontidae	a genus of birds