Aegyptopithecus zeuxis, also known as the Dawn Ape, is believed to be the common ancestor of Old World monkeys (the monkeys of Asia and Africa) and apes, including humans.

This small primate lived about 33 million years ago. It looked like a lemur, but its eye sockets were different.

Aegyptopithecus lived in trees and ate fruits and leaves. It probably moved around in treetops on all floors, like modern monkeys.

Its teeth resembled those of an ape.

The first known of Aegyptopithecus fossil - the intact skull of a male - was discovered in 1965 by Dr. Grant E. Mayer and Dr. Elwyn L. Simons of Yale's Peabody Museum.

The skull was found in Egypt's Fayum desert, which is about 60 miles south of Cairo.

In this area, there are lava flows from volcanoes that are no longer active. Water and wind have eroded these lava flows, exposing fossils.

When Aegyptopithecus was alive, this region was a subtropical forest.

Since then, paleontologists have discovered several more body parts of males.

The skull of a female was discovered in 2004.

A female Aegyptopithecus weighed about half the size of a male. Females weighed about 6 pounds and males weighed about 13 pounds.

This sexual dimorphism indicates that Aegyptopithecus was probably polygamous.

The name Aegyptopithecus means Egyptian ape. Zeuxis means linking - Aegyptopithecus zeuxis is the link between Old World monkeys and apes.