The Middle Stone Age archaeology of the Senegal River Valley

The importance of Africa in human origins is widely recognised, yet knowledge remains strongly biased towards certain regions of the continent at the expense of others. West Africa in particular is a vast area with extremely limited archaeological, environmental and fossil records. In this paper, we contribute towards redressing this imbalance though a summary of the state of knowledge of the West African Middle Stone Age (MSA), and the presentation of preliminary analyses of ten newly discovered MSA archaeological sites situated along the Senegal River. Archaeological, fossil and genetic data relevant to the West African MSA, a period currently thought to span from at least ∼150 ka until the Terminal Pleistocene, are first discussed. Technological analyses of newly discovered MSA assemblages in Senegal are then presented and contextualised with the ecology and environmental evolution of West Africa. Our preliminary findings suggest an overall high level of technological diversity along the Senegal River, but identify common technological features between assemblages in northern Senegal. These include an emphasis on centripetal methods of Levallois reduction (both preferential and recurrent). The discovery of tools in northern Senegal with basal modifications consistent with tanging may also suggest some form of connection with North African assemblages and is commensurate with the role of Senegal as a transitional zone between sub-Saharan and Saharan Africa. Although preliminary, the emerging results demonstrate the potential of the region to contribute to debates on intra-African dispersals, including population persistence and turnovers.