PLIOCENE ARCHAEOLOGICAL OCCURRENCES IN THE LAKE TURKANA BASIN

Archaeological evidence from the Lake Turkana basin, as well as from several other localities in eastern and central Africa, shows that stone tool manufacture and use occurred at least by the later part of the Pliocene, about 2.4 million years (Ma). However, little is known from the archaeological record about the technological characteristics of Ptiocene material culture, and related aspects of hominid behavior, such as habitat use and preference and subsistence of the tool makers. Expanded excavations at the West Turkana site of Lokalalei, dated to about 2.35 Ma indicate that hominids making artifacts at this site had little success in striking off whole flakes from the parent core forms. The large number of scars left on these forms consists of step, hinge, and small flakes (>2 cm) which may not have been very successful in cutting or slicing, despite the fact that the raw material utilized was a medium-grained volcanic lava with observable conchoidal fracture mechanics. The fauna is characterized by mainly size 1 or 2 bovids, suggesting early access if scavenged or hunted. This lithic technology patterning, which is shared by other assemblages in the basin, suggests that the Oldowan is not the earliest stone tool technology industry. Rather, the Oldowan represents a point in a continuum from simpler Pliocene technology characterized by little understanding of stone fracture mechanics to greater technological complexity and appreciation of fracture mechanics in the Pleistocene.