Blank predetermination in the Iberian Acheulean: fact or fiction? Insight from the cleaver on flake assemblage from Casal do Azemel site (Leiria, Portugal) by a Geometric Morphometric approach

The increase of data available for the study of the Middle Pleistocene in the Iberian Peninsula has favoured the understanding of the technological trends of the regional Acheulean techno-complex. This has features of Large Flake Acheulean -LFA- with a significant presence of cleavers on flake, a specific tool type that is of great cultural and technological value. Moreover, these tools are privileged to discuss the importance of predetermination in Acheulean assemblages. Following this reason, besides the traditional techno-typological approach, we perform 2D Geometric Morphometric Analysis (GMA) to explore this topic on the cleaver on flake assemblage from Casal do Azemel (Leiria, Portugal), a paradigmatic Iberian Acheulean site with a large number of cleavers on flake (more than 100 pieces), one of the largest collections of this type of tools in Western Europe.

The results obtained note a strong degree of shape homogeneity and suggest that the different technological solutions underlying the definition of the distal cutting edge, or the intensity of secondary reshaping, do not produce major differences in the overall shape of the tool. Therefore, this homogeneity is a consequence of the existence of a specific pattern of support selection and/or is the outcome of the already predetermined nature of the chosen blank. These observations allowed to discuss the significance of blank predetermination in the Acheulean, highlighting the existence of highly structured technological and cognitive prerequisites.