- Himalayacetus subathuensis
Location: Subathu Formation, northern India
Age: Early Eocene; 53 million years ago
Himalayacetus is an early ambulocetid whale known from a part of its lower jaw with teeth. It resembles those of Pakicetus with slight differences in the cusps. Oxygen isotope analysis of its teeth suggests that it drank saltwater, but its preservation in an oyster bed suggests it is also a marine mammal and may have hunted fish in both environments. The startling feature about Himalayacetus is its age. It predates the well-known Pakicetus, an accepted early whale relative. This means the whales diverged possibly as early as the late Paleocene or very early in the Eocene.
Bajpai, Sunil and Philip Gingerich "A new Eocene archaeocete (Mammalia, Cetacea) from India and the time of origin of whales" PNAS vol 95, December 1998 pgs 15464-15468