Kentriodon

Kentriodon is an extinct genus of toothed whale related to modern-day dolphins. Fossils have been found in Europe, Japan, Korea, and the Western Hemisphere. Seven species have been described so far.
Description.
"Kentriodon" was the most diverse of all the kentriodontids, which are represented by seventeen described genera. These were small to medium-sized odontocetes with largely symmetrical skulls, and thought likely to include ancestors of some modern species. "Kentriodon" is also the oldest described kentriodontid genus, reported from the Late Oligocene to the Middle Miocene.
Kentriodontines ate small fish and other nectonic organisms; they are thought to have been active echolocators, and might have formed pods. The diversity, morphology and distribution of fossils appear parallel to some modern species.