Indohyus ("India's pig") is a genus of extinct artiodactyl known from Eocene fossils in Asia, purported to be approximately 48 million years old. A December 2007 article in Nature by Thewissen et al. using an exceptionally complete skeleton of Indohyus from Kashmir indicates that raoellids may be the "missing link" sister group to whales (Cetacea). All other Artiodactyla are "cousins" of these two groups. δ18O values and osteosclerotic bones indicate that the raccoon-like or chevrotain-like Indohyus was habitually aquatic, but δ13C values suggest that it rarely fed in the water. The authors suggest this documents an intermediate step in the transition back to water completed by the whales, and suggests a new understanding of the evolution of cetaceans.