Table provides you the classification of the living primates. The primate fossil history dates back to 60 million years i.e. to Paleocene times, more specifically to the cretaceous age, The fossils of mammals of this period, their teeth, jaws and skulls bear affinities with Lemuroids.
In all these fossils apart from the structure of the molar teeth which is of primate character, there is a tendency in the skulls towards the expansion of the brain. Further there is a shortening of the face in these skulls, and the eyes which were initially laterally placed get a frontal
position. Also, there is a relative increase in the size of the cranium to accommodate a larger volume of brain.
The Lemurs found in the fossil records of the Eocene times were comparable to modern lemurs except that their brain was smaller and teeth specialisations were not found. Eocene times also showed tarsiers, the fossils of which showed primitive skulls, brain and limbs, significantly the number of teeth were reduced from 44 to 32, which is an anthropoid characteristic. Besides the numbers, the structure of the teeth with bicuspid premolars and tricuspid molars were typically anthropoid an in nature. Primates were abundant in North America and Europe until the end of Eocene and then disappeared completely.
There is a poor fossil record of primates in Oligocene times i.e. some 30 million years ago. In Egypt, in a place called Fayum a considerable diversity of primate remains were obtained. These primates belong to the genera Aegyptopithecus, Apidium, Aelopithecus and Oligopithecus. These fossils were clearly distinct from lemuroid fossils of Eocene times. All of them were small mammals and anthropoid in their characters. A nearly complete fossil of the skull jaws and other skeletal parts were obtained for Aegyptopithecus. The skeleton resembled that of a tree dweller, possessed a tail and was not a brachiator. The fossil suggested that the animal had along .snout, small bony eye sockets, sexual dimorphism of the canine and its teeth resembled those of apes. Possibly this animal was an ancestor of gibbons.