Semantor

a genus of fossil mammals of the order Pinnipedia. The Semantor were closely related to true seals, although they also resembled otters (for example, in the structure of the hind limbs). They represent a unique extinct group of pinnipeds that had adapted to life in large bodies of water, such as lakes and rivers, and were relatively mobile on dry land. Some paleontologists assign the Semantor to the subfamily of Lutrinae. Remains of the Semantor are known from Neocene deposits in Kazakhstan.