Objective: The purpose of this lab is for you to learn about some highlights in the fossil record and to see up dose casts of various fossil hominines, compare and contrast several morphological features, and begin the process of learning to distinguish the various forms from one another (Remember: a hominine is any human or fossil human ancestor). THE FOSSIL RECORD I OLIGOCENE PRE-HOMININES One Oligocene fossil stands out as significant to understanding the evolution of modern primates including humans. The Aegyptopithecus sp. (also known as the Dawn Ape) lived about 35 mya and was the largest of the Anthropoids in the Fayum deposits (Egypt), weighing 13 to 18 pounds. Its skull was similar to modern monkeys and had considerable sexual dimorphism. For our purposes it's most significant trait is that it has 1 the "2-1-2-3" dental formula shared by Old World anthropoids including humans. Although its brain size is relatively small, it is considered the best candidate to have given rise to Old World monkeys, apes and humans./nMIOCENE, PLIOCENE, AND PEISTOCENE HOMININES The earliest fossils that show clear evidence of an early hominine (hominid-like) creature are of Sahelanthropus tchadensis and Orrorin tugenensis, both around 6 million years ago at the end of the Miocene Epoch. Sahelanthropus sp. is represented by 3 isolated teeth, 2 jaw fragments and a nearly complete cranium. Orrorin sp. is represented by 2 jaw fragments, 6 isolated teeth, femoral pieces, partial humerus, hand phalanx but no reasonable complete cranial fragments. The femoral head of Orrorin sp. indicates bipedalism, but it is an equally good candidate for intermediary from between gorillas, chimps and australopithecines. The other significant fossil genus from this time period is Ardipithecus sp. There are two Ardipithicines (one 5.8-5.6 mya, one 4.4 mya) that have been named by Tim White, but the fossil material for both species is extremely thin. The best evidence is for Ardipithecus ramidus dating to 4.4 mya. According to White there are up to 50 individuals recovered from Aramis in Ethiopia, including many postcranial elements, but do date this information has not been published.

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