Indohyus

Indohyus (meaning "India's pig") is a small deer-like creature, which lived about 49 or 48 million years ago in Kashmir, India. It belongs to the artiodactyls family "Raoellidae", and is believed to be the closest sister group of Cetacea. It lived during the same time as the related "Pakicetus". The two may have coexisted.
About the size of a raccoon or domestic cat, this herbivorous creature shared some of the traits of whales. It also showed signs of adaptations to aquatic life, including a thick and heavy outer bone coating. This is similar to the bones of modern creatures such as the hippopotamus, and reduces buoyancy so that they can stay underwater. This suggests a similar survival strategy to the African mousedeer or water chevrotain which, when threatened by a bird of prey, dives into water and hides beneath the surface for up to four minutes.
There are two known species of Indohyus: