US Geological Survey


Date of this Version



Published in Journal of Human Evolution (1982) 11, 603-632.


In Oligocene times, the Fayum area of northern Egypt was a subtropical to tropical lowland coastal plain with damp soils and seasonal rainfall that supported an abundance and variety of vegetation, including lianes (large vines), tall trees, and possibly mangroves, and a large and varied vertebrate fauna. The Oligocene marine strandline was close by and principal Jebel Qatrani Formation streams were probably brackish several kilometers inland due to tidal incursions. Sediments of the Jebel Qatrani Formation were deposited by several large meandering streams, associated with minor but sometimes extensive flood basin ponds. These rocks provide no evidence for the former existence, in early Tertiary time, of a "Proto-Nile" River. Large accumulations of silicified fossil logs in the Jebel Qatrani Formation are autochthonous and the logs were transported only a short distance before burial. The Oligocene higher primates Argyplopithecus, , Propliopithecus, Parapithecus, and Apidium lived in this paleoenvironment and postcranial remains of Aegyptopithecus and Apidium demonstrate that these animals were arboreal. This scenario for the paleoenvironment of the Fayum area in Oligocene times differs greatly from the nearly treeless, sparsely vegetated, semiarid sahtlien Oligocene Fayum paleoenvironment populated by terrestrial primates that ,vas recently proposed by Kortlandt (1980).