Zygiocetus

Zygiocetus is a genus of cetotheriid mysticete in the subfamily Cetotheriinae. The type and only species is  Zygiocetus nartorum, known from the Late Miocene (Messinian) of Adygea in the Russian Caucasus.

Zygiocetus nartorum is distinguished from other cetotheriines in having slightly arched lambdoid crests, and it is distinct from Cetotherium and Kurdalagonus in having a wide supraoccipital that is shaped like an extended isosceles triangle with arched lateral sides.[1]