One of the land ancestors of all whales is a cloven-hoofed dog-like carnivore who lived during the Paleocene and Eocene periods, finally becoming extinct in the early Oligocene (that is, between about 62 and 30 million years ago) called the Mesonychid. Despite its appearance, however, it was not an ancestor of modern wolves. One of its evolutionary offshoots, called artiodactyls, were even-toed, hoofed creatures whose descendants would come to include pigs, cows, deer, and hippopotamuses. These last are considered the land mammals closest in relation to modern whales.
Mesonychid land ancestor if whales
