Morphological variation in Middle-Late Pleistocene stone points: a pan-African perspective

Abstract

Stone points are central to defining the African Middle Stone Age (MSA), yet their morphological variability has rarely been quantitatively examined at a continental scale. Longstanding distinctions between ‘specific’ industries (e.g., Aterian, Still Bay, Howiesons Poort) and more geographically widespread ‘generic’ MSA assemblages remain unresolved, in part because typological definitions of these cultural entities were historically based on qualitative assessments of limited samples. Here, we present the first continental-wide geometric morphometric analysis of Middle–Late Pleistocene stone points, focused on almost 1000 artefacts from 44 assemblages across eastern, northern, and southern Africa. Using outline-based elliptic Fourier analysis and multivariate statistics, we identify the main axes of shape variability and evaluate their relationships with size, region, cultural industries, raw materials, chronology, and modelled palaeoenvironmental conditions. We find that point shape is dominated by two main dimensions: an axis of elongation versus breadth (PC1), and the presence of basal tanging (PC2). Palaeoenvironment (primarily total annual precipitation and temperature seasonality) and region are the strongest predictors of shape in our sample. We find northern African Aterian points form the only consistently distinct cultural group compared to the general MSA point morpho-space, driven primarily by the prevalence oftanged bases (PC2). In contrast, our (smaller) sample of southern African Howiesons Poort and Still Bay retouched points fall mostly within the broader range of “generic” MSA variability. Raw material properties also exert significant constraints on point shape. This quantitative framework helps refine interpretations of cultural characterisations within the MSA and contributes to broader models of behavioural evolution during the African Middle–Late Pleistocene.