Indohyus

Indohyus (meaning "Indian pig", from Greek ινδός, indos, meaning 'Indian' and ὗς, hus, meaning 'pig' or 'swine') is an extinct genus of raoellid artiodactyl known from Eocene fossils in Asia. The fossils were discovered among rocks that had been collected in 1970 in Kashmir by the Indian geologist A. Ranga Rao, who found a few teeth and parts of a jawbone. He named the type and only species, Indohyus indirae, one year later. In 2007, Hans Thewissen recognised an auditory bulla, a highly distinctive ear structure found only in cetaceans, in a broken skull collected from these rocks and given to him by Ranga Rao's widow. Later analysis of oxygen-18 values and the presence of osteosclerotic bones indicate that the chevrotain-like Indohyus was habitually aquatic. About the size of a fox, this omnivorous pig-like creature shared some of the traits of whales, and showed signs of adaptations to aquatic life. Their bones were similar to the bones of modern creatures such as the hippopotamus, and helped reduce buoyancy so that they could stay underwater. This suggests a survival strategy similar to that of 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. Indohyus was possibly sexually dimorphic, as significant intraspecific variation in the size of its maxillary canine teeth has been interpreted as evidence of such.