Named By: Thewissen et al - 1996.
Classification: Chordata, Mammalia, Cetacea, Archaeoceti, Ambulocetidae, Ambulocetinae.
Species: A. natans.
Size: 3 meters long.
Known locations: Pakistan.
Time period: Ypresian of the Eocene.
Fossil representation: Several individuals with partial remains, one specimen with a much more complete skeletal frame.
is a very important transitional fossil as it displays the link between
terrestrial mammals and the early whales. Ambulocetus
name from the fact that it could both swim by undulating its back
as well as leave the water and walk on land.
The ear structure of Ambulocetus is very interesting as it appears to have only worked while it was underwater. If Ambulocetus ever hunted on land, it may have had to use another method to detect prey such as holding its throat to the ground and sensing vibrations in a similar manner as other creatures that lack ears.
The skull of Ambulocetus is arranged in such a way that it could swallow food while underwater. This was achieved by the arrangement of air passages in the snout. The teeth were also very similar to other early cetaceans and a chemical analysis of these teeth has shown them to have been exposed to both fresh and salt water. This implies that Ambulocetus was active in river estuaries where fresh meets salt water, but can also suggest that Ambulocetus was a go anywhere predator. Other primitive whales important to the study of whale evolution include Pakicetus and Rodhocetus.