Ocepeia daouiensis (Gheerbrant et al 2001, 2014; Paleocene, 60 mya; 9 cm skull length) is a Hippopotamus and mesonychid ancestor derived from a sister to Phenacodus. The original reconstruction was not an accurate representation of the fossil CT scan (above at right).
The pneumatized skull contains many air spaces. The larger skulls have larger canines and so are considered male. The jugal deepens below the orbit, hiding the posterior molars in lateral view. The premaxilla is transverse. The upper canine rubs against the lower large incsior creating a facet, as in hippos and Harpagolestes.
Ocepeia was found with aquatic taxa and was probably amphibious. Mesonychids became land hippos. Hippos gave rise to anthracobunids, desmostylians, thick-tailed desmostylians and finally baleen whales.
The name Ocepeia derives from the initials of Office Chérifien des Phosphates (O.C.P.), the national Moroccan phosphate mining company.