Ambulocetus

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Ambulocetus
Fossil range: Eocene

Extinct (fossil)

Scientific classification

Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Cetacea
Suborder:	Archaeoceti
Family:	Ambulocetidae
Subfamily:	Ambulocetinae
Genus:	Ambulocetus
Species:	A. natans

Binomial name

Ambulocetus natans
Thewissen et al., 1996

Reconstruction of Ambulocetus natans

Ambulocetus was an early cetacean that could walk as well as swim. It is a transitional fossil that shows how whales evolved from land-living mammals. Its name means 'walking whale'. Having the appearance of a three-metre long mammalian crocodile, it was clearly amphibious, as its back legs are better adapted for swimming than for walking on land, and it probably swam by undulating its back vertically, as otters, seals and whales do. It has been speculated that Ambulocetids hunted like crocodiles, lurking in the shallows to snatch unsuspecting prey. Chemical analysis of its teeth shows that it was able to move between salt and fresh water.

Ambulocetus did not have external ears. To detect prey on land, they may have lowered their heads to the ground and felt for vibrations.

The reason why scientists consider Ambulocetus to be an early whale is that it shares underwater adaptations with them: it had an adaptation in the nose that enabled it to swallow underwater, and it shared ear structure with whales, enabling it to hear well underwater. In addition, its teeth are similar to those of cetaceans.

The Ambulocetus fossils were found in Pakistan by anthropologist Johannes Thewissen. When the animal was alive, Pakistan was a coastal region bordering the ancient Tethys Sea.

1 In popular culture
2 See also
3 References
4 External links

[edit] In popular culture

Ambulocetus was featured in Walking With Beasts as a crocodile-like ambush predator.
Fighting Natans is the mascot for North Eastern Ohio Universities College of Medicine, the school at which Hans Thewissen currently works.

[edit] See also

Evolution of cetaceans

[edit] References

J. G. M. Thewissen, S. I. Madar, and S. T. Hussain (1996). "Ambulocetus natans, an Eocene cetacean (Mammalia) from Pakistan". Courier Forschungsinstitut Senckenberg 191: 1-86.