Regional variability in the Acheulian to Middle Stone Age transition in southern Africa.

Homo sapiens emerged in Africa around 300 − 200 thousand years ago (ka). Although the earliest H. sapiens fossils are associated with the Middle Stone Age (MSA), lithic technologies considered diagnostic of the MSA have been found alongside Acheulian technology in eastern Africa and the interior of southern Africa by ~ 500 − 400 ka, suggesting a deep evolutionary history of our species in these regions. The southern coastal plain of South Africa, geographically separated from the interior by the Cape Fold Belt and Great Escarpment, has one of the best documented records of the MSA in Africa; however, only a single site is older than 125 ka and little is known about the origins of the MSA in this region. Here, we report a stratified sequence of Acheulian to MSA lithic assemblages from the open-air site of Amanzi Springs covering the period between ~ 379 to 95 ka. We show that the MSA emerged around 230 ± 18 ka, significantly earlier than previously documented along the southern coast. The pattern of technological change also differs to the interior, with no diagnostic MSA elements found in the late Acheulian, although persistent methods of flake production indicate a gradual transition and continuity into the MSA. The relatively late emergence of the MSA along the southern coast highlights the variable and complex nature of demographic and behavioural change during this period, with regionally distinct technological trajectories extending into the Middle Pleistocene in southern Africa.