rorqual vs whalebone whale

rorqual and whalebone whale both are nouns.

Word	Noun	Adjective	Verb	Adverb
rorqual	Yes	No	No	No
whalebone whale	Yes	No	No	No

As nouns, whalebone whale is a hypernym of rorqual; that is, whalebone whale is a word with a broader meaning than rorqual:

rorqual: any of several baleen whales of the family Balaenopteridae having longitudinal grooves on the throat and a small pointed dorsal fin
whalebone whale: whale with plates of whalebone along the upper jaw for filtering plankton from the water

Other hypernyms of rorqual include baleen whale.

rorqual (noun)	whalebone whale (noun)
any of several baleen whales of the family Balaenopteridae having longitudinal grooves on the throat and a small pointed dorsal fin	whale with plates of whalebone along the upper jaw for filtering plankton from the water