Parietobalaena is an extinctgenus of baleen whale, belonging to the family Pelocetidae. Fossils are found in Miocene-aged marine strata in North America, Europe, Australia, and Japan, including the Temblor and Itahashi formations.[1][2][3][4][5] Based on previous estimates of juvenile specimens, Tsai (2017) suggested a body size of 12-15 m for P. yamaokai, akin to that of the gray whale.[5]
Otsuka, H.; Ota, Y. (2008). "Cetotheres from the early Middle Miocene Bihoku Group in Shobara District, Hiroshima Prefecture, West Japan". Miscellaneous Reports of the Hiwa Museum for Natural History. 49: 1–66.