See text Balaenoptera (from Latin balaena 'whale' and Ancient Greek πτερά (pterá) 'fin') is a genus of rorquals containing eight extant species.

[2] Balaenoptera comprises all but two of the extant species in its family (the humpback whale and gray whale); the genus is currently polyphyletic, with the two aforementioned species being phylogenetically nested within it.

[3] This genus is known in the fossil records from the Neogene to the Quaternary (13.65 million years ago to the present).

Some (namely B. borealina, B. definata, B. emarginata, B. gibbosa, B. rostratella, and B. sibbaldina) are either nondiagnostic, highly fragmentary, or had no holotype specimen named, hence are considered nomina dubia.

[8][9] The valid fossil species of Balaenoptera are: