Experimentation preceding innovation in a MIS5 Pre-Still Bay layer from Diepkloof Rock Shelter (South Africa): emerging technologies and symbols

In southern Africa, key technologies and symbolic behaviors develop as early as the later Middle Stone Age in MIS5. These innovations arise independently in various places, contexts and forms, until their full expression during the Still Bay and the Howiesons Poort. The Middle Stone Age sequence from Diepkloof Rock Shelter, on the West Coast of the region, preserves archaeological proxies that help unravelling the cultural processes at work. This unit yields one of the oldest abstract engraving so far discovered in Africa, in the form of a rhomboid marking on the cortical surface of an ungulate long bone shaft. The comprehensive analysis of the lithic artefacts and ochre pieces found in association with the engraved bone documents the transport of rocks over long distance (>20km), the heat treatment of silcrete, the coexistence of seven lithic reduction strategies (including the production of bladelets and the manufacture of unifacial and bifacial points), the use of adhesives and the processing of ochre. At Diepkloof, the appearance of engraving practices take place in a context that demonstrates a shift in rock procurement and a diversification in lithic reduction strategies, suggesting that these behavioral practices acted as a cultural answer to cope with new environmental and/or socio-economic circumstances. We argue that the innovations later found during the Still Bay and the Howiesons Poort were already in the making during the MIS5 pre-Still Bay, though not all the benefits were yet taken advantage of by the populations.