A new species of Middle Miocene baleen whale from the Nupinai Group, Hikatagawa Formation of Hokkaido, Japan.

A fossil whale from the Hikatagawa Formation (Middle Miocene, 15.2-11.5 Ma) of Hokkaido, Japan is described as a new genus and species and its phylogenetic position is examined. Consistent with the result of Marx, Lambert & de Muizon (2017), the Cetotheriidae form a clade with the Balaenopteroidea, and "a clade comprising and related taxa" is located basal to the Balaenopteroidea + Cetotheriidae clade. is placed in the clade with most of members of "Cetotheres" sensu lato comprising and related taxa. can be distinguished from the other members of "Cetotheres" sensu lato in having an anteriorly swollen short zygomatic process, high triangular coronoid process, and angular process, which does not reach as far posterior as the mandibular condyle. is only record of "Cetotheres" sensu lato from Hokkaido, Japan and the northern-most records of "Cetotheres" sensu lato in Japan.