it was non-functional, and the malleus and jawbone (which are connected in the embryo stage of mammals) happened to stop separating. Palaeoecology During the Eocene, the Indian subcontinent was an island just beginning its collision with Asia which would eventually lead to the uprising of the Himalayas. The Eocene had a greenhouse climate (no permanent ice sheets at the poles) as opposed to the icehouse climate of today, so, in general, areas were much warmer. The abundance of Eocene brown coal deposits preserving tropical biota on the Indian subcontinent indicates the proliferation of tropical rainforests in a hot climate. Mangroves seem to have commonly grown along the subcontinent's western margin in the Early Eocene but decreased nearing the Middle Eocene Climatic Optimum (a warming trend). The waters off the western coast seem to have featured upwelling and low oxygen. The holotype was identified in the upper level of the Kuldana Formation at Locality 9209, which features green mud and silt as well as a bed of marine shells, including marine snails (such as Turritella) and bivalves. It was likely a coastal area. A redbed underlies this layer, followed by grey, green, and purple freshwater mud, silts, sandstones, and limestone. These beds alternate with showing marine deposits. The holotype was found in green mud. Near Locality 9209, the formation begins with of grey and green mud, silt, and sandstone, containing two bivalve beds. The first often stretches only one shell, whereas the second stretches down, and the formation terminates with a bed before transitioning to the younger Kohat Formation. The holotype was found a few decimeters above the second bed. The area may have formed in a shallow sea off the shores of a coastal swamp or forest. The only other vertebrate remain found at the 9209 locality was a (now lost) reptile scute. Other localities of the upper level of the formation have yielded remains of requiem sharks, the fish Stephanodus, catfish, turtles, crocodiles, and the anthracobunid Anthracobune pinfoldi. Other archaeocetes from the formation are: the ambulocetid Gandakasia, the remingtonocetid Attockicetus, and the pakicetids Nalacetus, Pakicetus calcis, and P. chittas. Stable carbon and oxygen isotope analysis indicates Ambulocetus inhabited brackish waters (part fresh and part salt water), possibly at a river mouth. See also Evolution of cetaceans Ice Hunt — novel by James Rollins featuring Ambulocetus Notes References External links Ambulocetidae Prehistoric cetacean genera Lutetian life Eocene mammals of Asia