Stone tools recovered from near the Senegalese coast extend occupation of the region back to 150 thousand years ago and are comparable to those seen across Africa at this time, but uniquely persist in the region until 10 thousand years ago

Evidence from West Africa about human evolution remains scarce, but recent research has indicated unique patterns of cultural change in comparison to other regions of the continent. A new article in the journal Nature Ecology and Evolution adds to our understanding with a study of the oldest directly dated archaeological site in West Africa. The site shows technological continuity spanning roughly 140,000 years and offers insights into the ecological stability of the region.

Our species emerged in Africa around 300 thousand years ago and until around 30-60 thousand years ago typically used tools and tool-making techniques referred to as Middle Stone Age toolkits. Around that time, distinct Later Stone Age toolkits began to emerge in northern, eastern, and southern Africa. While recent evidence suggests Middle Stone Age toolkits persisted in West Africa much later, to around 10 thousand years ago, the antiquity of these technologies is poorly understood.

The new study, led by scientists from the MPI of Geoanthropology, Université Cheikh Anta Diop de Dakar, University of Sheffield, and University of South Florida, extends the timeframe in which Middle Stone Age toolkits are known from West Africa to 150 thousand years ago, based on excavations from the near-coastal site of Bargny 1.1

The site itself is located close to the modern coastline, south of Dakar, Senegal. While no artefacts indicating direct human engagement with coastal resources were recovered at the site, study of the associated environments offer a wider perspective.2

The study highlights long-term durability of core elements of Middle Stone Age toolkits in West Africa without evidence for the appearance of specialized technological developments observed elsewhere.  

  • 1. “The stone tool assemblage dating from 150 thousand years ago shows classic features of the Middle Stone Age, with the use of Levallois and discoidal reduction methods and the use of small retouched flake tools rather than larger implements,” says Dr Khady Niang, lead author of the study. “The assemblage from Bargny 1 is closely comparable to those of a similar age from across the continent, and is the first site from West Africa dating to the Middle Pleistocene, prior to the onset of substantial technological regionalization elsewhere in Africa.”
  • 2. “We found mangrove and brackish wetland plant microfossils associated with the site’s occupation,” adds Dr Chris Kiahtipes of the University of South Florida, co-author on the study. “This is particularly interesting because it shows that the site was located near an estuary and demonstrates how important these habitats are to humans past and present.”
150-thousand-year-old sediments at Bargny 1 that contain West Africa’s oldest Middle Stone Age toolkits
150-thousand-year-old sediments at Bargny 1 that contain West Africa’s oldest Middle Stone Age toolkits © Jimbob Blinkhorn

Niang, K., Blinkhorn, J., Bateman, M.D. et al. Longstanding behavioural stability in West Africa extends to the Middle Pleistocene at Bargny, coastal Senegal. Nat Ecol Evol, 2023 DOI: 10.1038/s41559-023-02046-4

Middle Stone Age (MSA) technologies first appear in the archaeological records of northern, eastern and southern Africa during the Middle Pleistocene epoch. The absence of MSA sites from West Africa limits evaluation of shared behaviours across the continent during the late Middle Pleistocene and the diversity of subsequent regionalized trajectories. Here we present evidence for the late Middle Pleistocene MSA occupation of the West African littoral at Bargny, Senegal, dating to 150 thousand years ago. Palaeoecological evidence suggests that Bargny was a hydrological refugium during the MSA occupation, supporting estuarine conditions during Middle Pleistocene arid phases. The stone tool technology at Bargny presents characteristics widely shared across Africa in the late Middle Pleistocene but which remain uniquely stable in West Africa to the onset of the Holocene. We explore how the persistent habitability of West African environments, including mangroves, contributes to distinctly West African trajectories of behavioural stability.

Fig. 2: Photo of sediment section at Bargny 1 and the results of geochronological, sedimentological and palaeoecological analyses.
Fig. 2: Photo of sediment section at Bargny 1 and the results of geochronological, sedimentological and palaeoecological analyses. - Top, photo of excavated and sampled section at Bargny 1 (outlined in white), illustrating the division of major sediment units (red) and the locations of dating samples (blue). Bottom left, log diagram of sediment units, illustrating relative position of geochronological samples (black dots) with results of sedimentological and palaeoecological studies including mean fine-sediment particle size (pink; nm), sorting (blue), total organic matter (%; yellow), carbonates (%; green), diagnostic phytoliths (log-transformed concentration, purple) and diagnostic pollen (log-transformed concentration, orange).