Hapalodectes

Hapalodectes (literally "soft biter"; ἁπαλός, hapalos = "soft, tender", δῆκτῆς, dêktês = "biter") is an extinct genus of otter-like mesonychids from the Late Paleocene to Early Eocene some 55 million years ago. Although the first fossils were found in Eocene strata of Wyoming, the genus originated in Mongolia, as the oldest species is H. dux, which was found in Late Paleocene strata in the Naran Bulak Formation.

The genus was once suggested to be related to the Archaeoceti, such as Pakicetus, due to extreme similarities between the skull and teeth anatomies of the two genera. Now, however, Hapalodectes and other mesonychians are thought to be related to basal artiodactyls, while the Archaeoceti are now determined to be descended from more derived artiodactyls, like Indohyus, which are related to hippopotamuses and anthracotheres.