Pelagiarctos

Pelagiarctos was a genus of walrus that lived during the Middle Miocene, approx. 13-15 mya. Its fossilised remains have been found in the Sharktooth Hill Bonebed, in Kern County, California. It was originally described as an Otariidae, though it is now usually considered to be a basal Odobenidae.

==Anatomy== To date, the only material of Pelagiarctos that has been found includes a handful of partial mandibles. The mandibles themselves are approximately the same size as those of the contemporaneous pinniped Allodesmus kernensis, but differ in that the cheek teeth have two roots (instead of one, as in Allodesmus) and that the dentary itself is much thicker. They are also highly vascularized and covered in unusually large mental foramina, indicating that Pelagiarctos may have had somewhat fleshy lips. The cheek teeth resemble those of several terrestrial carnivores, specifically borophagine dogs and hyaenids. This, coupled with the robust dentary, indicates that Pelagiarctos probably had a large bite force. Though no postcranial remains have yet been found, the size of the dentary suggests an overall length of approx. 2.5–3 meters.