Pakicetus

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Pakicetus
Fossil range: Early Eocene

Illustration by Carl Buell, from [2]

Scientific classification

Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Cetacea
Suborder:	Archaeoceti
Family:	Pakicetidae
Subfamily:	Pakicetinae
Genus:	Pakicetus
Species:	P. inachus

Binomial name

Pakicetus inachus
Gingerich & Russell, 1981

Reconstruction of Pakicetus

Pakicetus is a genus of extinct cetaceans found in the early Eocene of Pakistan, whence their name. The strata where the fossils were found was then part of the coast of the Tethys Sea.

The first fossil, a lone skull, was thought to be a mesonychid, but Gingerich and Russell recognized it as an early cetacean from characteristic features of the inner ear, found only in cetaceans: the large auditory bulla is formed from the ectotympanic bone only. This suggests that it is a transitional species between extinct land mammals and modern cetaceans.

Complete skeletons were discovered in 2001, revealing that Pakicetus was primarily a land animal, about the size of a wolf, and very similar in form to the related mesonychids.

[edit] References

P. D. Gingerich & D. E. Russell (1981). "Pakicetus inachus, a new archaeocete (Mammalia, Cetacea) from the early-middle Eocene Kuldana Formation of Kohat (Pakistan)". Univ. Mich. Contr. Mus. Paleont 25: 235–246.
J. G. M. Thewissen, E. M. Williams, L. J. Roe and S. T. Hussain (2001). "Skeletons of terrestrial cetaceans and the relationship of whales to artiodactyls". Nature 413: 277–281. Abstract