Research on late Pliocene Oldowan sites at Kanjera South, Kenya

The late Pliocene is notable for the appearance of two new hominid genera a s well as the first archaeological sites, generally attributed to the Oldow an Industrial Complex. However, the behavioral ecology of Oldowan hominids has been little explored, particularly at sites older than 2.0 Ma. Moreover , debates on Oldowan hominid foraging ecology and behavior have centered on data from only two regions, and often from single site levels. Here we des cribe the preliminary results of our investigation of Oldowan occurrences a t Kanjera South. These occurrences preserve the oldest known traces of homi nid activity in southwestern Kenya, and unlike most of the Oldowan sites in the 2.0-2.5 Ma time interval, artefacts are found in spatial association w ith a well-preserved fauna. In 1996 and 1997, this project initiated the first excavation program for K anjera South. Magneto- and biostratigraphy indicate that deposition began a pproximately 2 2 Ma, substantially earlier than previously thought. At Exca vation 1, artefacts were found in spatial association with a taxonomically diverse faunal assemblage in Beds KS-1 and KS-2. Excavation 2 yielded a par tial hippopotamus axial skeleton with artefacts in KS-3. Cores from both si tes were incidentally flaked and represent a Mode I lithic technology indis tinguishable from the Oldowan. Approximately 15% of the artefacts were manu factured from non-local raw materials, indicating a flow of resources into the area. Stable isotopic analysis of KS-I and KS-2 pedogenic carbonates suggests tha t the Excavation 1 assemblages formed in a relatively open (>75% C-4 grass) habitat. The Excavation 1 and 2 faunas contain a high proportion of equids relative to Oldowan accumulations from Bed I Olduvai Gorge, Tanzania. Beds KS-1 and KS-2 thus preserve traces of Oldowan hominid activities in a more open setting than has been previously documented. (C) 1999 Academic Press.