Protocetus

Protocetus Temporal range: Middle Eocene PreЄ Є O S D C P T J K Pg N
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Underside of a skull cast at the Museum für Naturkunde, Berlin
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Cetacea
Suborder:	Archaeoceti
Family:	Protocetidae
Genus:	Protocetus
Species:	P. atavus
Binomial name
Protocetus atavus Fraas 1904

Protocetus atavus ("first whale") is an extinct species of primitive cetacean from Egypt. It lived during the middle Eocene period 45 million years ago.

The first discovered protocetid, Protocetus atavus was described by Fraas 1904 based on a cranium and a number of associated vertebrae and ribs found in middle Lutetian Tethyan marine limestone from Gebel Mokattam near Cairo, Egypt.

Description

File:Protocetus BW.jpg

Restoration

Protocetus had a streamlined, whale-like body around 2.5 metres (8.2 ft) long, but was relatively primitive in many respects; it still had small hind flippers, and its front flippers had webbed toes. Its jaws were long and lined with deadly teeth. The shape of the bones in the tails suggests that it may have evolved tail flukes, like those of modern whales, and, while it did not have a true blowhole, the nostrils had already begun to move backwards on the head.

Unlike its more primitive predecessor Pakicetus, the structure of the ears suggests that Protocetus was able to hear properly underwater, although it is unlikely that it could echolocate. Similarly, it retained sufficient olfactory apparatus to have a good sense of smell, although it probably relied more on its eyesight to find prey.

See also

• Evolution of cetaceans