US Geological Survey


Date of this Version



Published in Science, New Series, Vol. 234, No. 4781 (Dec. 5, 1986), pp. 1247-1249.


The earliest fossil record of African anthropoid prunates (monkeys and apes) comes from the Jebel Qatrani Formation in the Fayum depression of Egypt. Reevaluation of both geologic and faunal evidence indicates that this formation was deposited in the early part of the Oligocene Epoch, more than 31 million years ago, earlier than previous estimates. The great antiquity of the fossil higher prunates from Egypt accords well with their primitive morphology compared with later Old World higher prunates. Thus, the anthropoid primates and hystricomorph rodents from Fayum are also considerably older than the earliest higher primates and rodents from South America.