Old stones’ song—second verse. Use-wear analysis of rhyolite and fenetized andesite artifacts from the Oldowan lithic industry of Kanjera South, Kenya

This paper investigates Oldowan hominin behavioral ecology through use-wear analysis of artifacts from Kanjera South, Western Kenya.Itextendsdevelopmentofourexperimentaluse-wearreferencecollectionandanalysisofuse-wearonthewellpreservedand unweatheredOldowantoolsfromthissitetoincluderhyolite,anon-localmaterialof similar durability topreviously studiedquartz and quartzite tools, and fenetized andesite, a local material with considerably less durability. Variability in rhyolite and fenetized andesite texture, inclusions, and matrix required enhancement of previous methods so we combine the use of stereoscopic, metallographic, and scanning electron microscopy in this study. This study allows us to begin exploration of the links between specific artifactual raw materials and the materials they were used to process. Data assembled so far suggest that tools fashioned from non-local and local stone were, with one possible exception, used to process similar materials. Additionally, experiments carried out with replicas of tools made of rhyolite and fenetized andesite confirm interpretation of reduction sequences that tools madeoflessdurablelocalmaterialhadashorteruse-lifeandwereusedexpedientlycomparedtothemoredurablenon-localquartz, quartzite, and rhyolite. These new data improve our understanding, of the functional needs, behavioral solutions, and cognitive capacities of Oldowan hominins. Finally, these data show how use-wear analysis, combined with lithic raw material and lithic technology, can be a powerful means for evaluating two key points for human evolution: long-term memory, and planning.