What is "cornwallius"

Cornwallius is an extinct herbivorous marine mammal of the family Desmostylidae. Cornwallius lived along the North American Pacific Coast from the Early Oligocene ( Chattian) through the Oligocene (28.4 mya—20.6 Mya) and existing for approximately .

The type locality is the Chattian Sooke Formation, Vancouver Island, British Columbia, Canada (, paleocoordinates ).

Cornwallius was named by . Its type is Desmostylus sookensis, named by and recombined to Cornwallius sookensis by .

Fossils have been discovered from Baja California Peninsula, Oregon and Washington coasts, and Unalaska Island.