Paleoparadoxia

Paleoparadoxia ("ancient paradox") is a genus of large, herbivorous aquatic mammals that inhabited the northern Pacific coastal region during the Miocene epoch (). It ranged from the waters of Japan (Tsuyama and Yanagawa), to Alaska in the north, and down to Baja California, Mexico. "Paleoparadoxia" was about long.
Description.
"Paleoparadoxia" is thought to have fed primarily on seaweeds and sea grasses. The jaws and the angle of the teeth resemble a backhoe bucket. Its bulky body was well adapted for swimming and underwater foraging. Originally interpreted as amphibious, "Paleoparadoxia" is now thought to have been a fully marine mammal like their living relatives, the sirenians, spending most of their lives walking across the sea bottom like marine hippos. Studies on its habitat preference show that it favoured deep, offshore waters.
 named the genus "Cornwallius" but synonymized it as a species of "Paleoparadoxia".