''Miobalaenoptera'' is an extinct genus of

rorqual Rorquals () are the largest group of baleen whales, which comprise the family Balaenopteridae, containing ten extant species in three genera. They include the largest animal that has ever lived, the blue whale, which can reach , and the fin ...

from the

Late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene Epoch made up of two stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million years ago) to 5.333 Ma. The ...

(Messinian) of Japan.

Description

''Miobalaenoptera'' is distinguished from other rorquals (both extinct and extant) in the features of the earbone (incl. periotic) as well strongly diverging basioccipital crests The holotype specimen was found in marine deposits in Numata town, Hokkaido, Japan. It was initially assigned to ''Balaenoptera'' cf. ''acutorostrata'' by Shinohara (2012) and thought to be Pliocene in age, but analysis of diatoms in the matrix and preparation showed it to not only late Miocene but also a distinct species of extinct rorqual.Shinohara, S. 2012. A fossil whale (Balaenoptera sp.) from the early Pliocene in Numata, Hokkaido, Japan. Annual Report of Numata Fossil Museum, 12, 19–22.

References

Miocene cetaceans Prehistoric cetacean genera Miocene mammals of Asia Fossil taxa described in 2019 {{paleo-whale-stub