In Depth
Diorocetus was first named from fossils recovered from the United States by R. Kellog in 1968, establishing the type species Diorocetus hiatus. Then in 2003 and 2008 respectively two new species, Diorocetus chichibuensis and Diorocetus shobarensis were named from fossils discovered in Japan. Out of these D. shobarensis seems to be the earliest with fossils roughly dated to the Burdigalian of the Miocene, while at the time of writing fossils for D. hiatus and D. chichibuensis are Langhian to Serravalian in age. Noted for having quite a slender skull for a mysticetid whale, Diorocetus was considered in a 2009 study by Beatty & Dooley to potentially be a bottom feeder as opposed to feeding in open water like the baleen whales that we know today.
Diorocetus might have been preyed upon by large ‘megatoothed sharks’ such as C. chubutensis and of course the famous C. megalodon.
Further Reading
- A hitherto unrecognized Calvert Cetothere. Bulletin of the United States National Museum 247(6):133-161 - R. Kellogg - 1968. - New cetothere (Cetacea: Mysticeti) from the Miocene Chichibumachi Group, Japan. - Bulletin of the Saitama Museum of Natural History 20-21:1-10. Bulletin 247:133-161. - K. Yoshida, T. Kimura & Y. Hasegawa - 2003. - Cladistic analysis and a revised classification of fossil and recent mysticetes. - Zoological Journal of the Linnean Society 150:875-894. - M. E. Steeman - 2007. - 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 (2) :1-66. - H. Otsuka & Y. Ota - 2008. - Injuries in a Mysticete Skeleton from the Miocene of Virginia, With a Discussion of Buoyancy and the Primitive Feeding Mode in the Chaeomysticeti. - Jeffersoniana, Virginia Museum of natural History, 20. Brian Lee Beatty & Alton C. Dooley Jr - 2009.
