Ambulocetidae
The First Costal Whales


The skeleton of Ambulocetus natans
(approximately 12 feet long)
To see a flesh-and-blood reconstruction go to Carl Buell's painting.


Ambulocetids are large, powerful animals, with short limbs, but big feet, and a strong tail. They are only found in northern Pakistan and western India in rocks that indicate that the environment was nearshore marine and swampy. These rocks cannot be dated with great accuracy, but they are clearly younger than the sediments in which pakicetids are found. Although ambulocetids could walk on land as well as swim, it is clear that they were not fast on either terrain. The post-cranial skeleton of ambulocetids is well known thanks to the discovery of a very complete skeleton of the species Ambulocetus natans. The name of this whale means “the walking and swimming whale,” and indicates that it was amphibious. Ambulocetus was first described by Thewissen et al. (1994), and later, in more detail, by Thewissen et al. (1996)

The bones of Ambulocetus natans arranged in its approximate body shape. These are the original fossils, all pertaining to a single individual. Note hammer for scale.

Three genera of whales make up the family Ambulocetidae: Ambulocetus , Gandakasia , and Himalayacetus . Gandakasia and Himalayacetus are only known from a single lower jaw fragment each, and cannot be compared in detail with Ambulocetus .

Head of Ambulocetus as drawn by Marion Lipka

Some publications on ambulocetids:
Thewissen, J.G.M., S.T. Hussain, and M. Arif. 1994. Fossil evidence for the origin of aquatic locomotion in archaeocete whales. Science 263:210-212.
Thewissen, J.G.M., S. I. Madar, and S. T. Hussain. 1996. Ambulocetus natans, an Eocene cetacean (Mammalia) from Pakistan. Courier Forschungs-Institut Senckenberg, 190:1-86.
Thewissen, J.G.M., and F. E. Fish. 1997. Locomotor evolution in the earliest cetaceans: functional model, modern analogues, and paleontological evidence. Paleobiology 23:482-490.
Madar, S.I., J. G. M. Thewissen, and S. T. Hussain. 2002. Additional holotype remains of Ambulocetus natans (Cetacea, Ambulocetidae), and their implications for locomotion in early whales. Journal of Vertebrate Paleontology 22:405-422.

All pictures on Dr.Thewissen’s website are public access, but the source must be identified immediately near the place where it is used (i.e., on the same webpage, or in the caption of the figure used).