Balaenoptera, from balaena and pteron, is a genus of Balaenopteridae, the rorquals, and contains eight extant species. The speciesBalaenoptera omurai was published in 2003. Balaenoptera is a diverse genus and comprises all but one of the extant species in its family—the other species is the humpback whale. This genus is known in the fossil records from the Neogene to the Quaternary. from the Pliocene in Italy
Many fossil Balaenoptera species have been described. Some are either nondiagnostic, highly fragmentary, or had no holotype specimen named, hence are considered nominadubia. The species "Megaptera" hubachi may in fact be a species of Balaenoptera, and is certainly not a member of Megaptera. The valid fossil species of Balaenoptera are:
†Balaenoptera cephalus was originally thought to be a species of Eschrichtius or Cetotherium, but more recent analysis shows it to be a member of Balaenoptera. Fossils of the species were found in the Calvert Formation of Maryland.
†Balaenoptera colcloughi is known from four specimens, including four skulls and some postcranial remains, found at the San Diego Formation. It was a close relative of Megaptera novaeangliae, B. siberi, and B. physalus.
†"Balaenoptera" cortesii is a small species based on a juvenile specimen from Montezago; it probably represents a distinct, unnamed genus of balaenopterid.
†Balaenoptera davidsonii, like B. cephalus, was originally classified under Eschrichtius, but it has since been moved to Balaenoptera. It was native to the Pliocene San Diego Formation of California. The only known fossil of B. davidsonii is a fragment of the left dentary.
†"Balaenoptera" portisi is based on MGPT 13803 from Montafia, and may be the same genus or species as Cetotheriophanes capellinii. The species "B. floridana" is indistinguishable from "B." portisi.
†"Balaenoptera" ryani represents a genus of basal balaenopterid distinct from Balaenoptera.
†Balaenoptera siberi is known from two complete skeletons. Its affinity with the genus Balaenoptera has been questioned.
†Balaenoptera sursiplana is a fragmentary species, based on a single fossilized tympanic bone.
†Balaenoptera taiwanica is named after Taiwan, where the fossil was found in the Pliocene-aged Cholan Formation. B. taiwanica is also based on a single tympanic bone, which is similar to that of B. physalus, the fin whale.
