Ambulocetus was an amphibious early cetacean with short limbs and large feet used for swimming and perhaps also walking on land. It lacked the tail fluke, present in later early whales. Its pelvis was attached to its spine, like land mammals and unlike later whales. Along with other members of Ambulocetidae, it is a transitional fossil that shows how whales evolved from land-living mammals. It is also named the walking whale because of this; but recent studies show that it was fully aquatic like modern cetaceans.