Morphometric Assessment of Convergent Tool Technology and Function during the Early Middle Palaeolithic: The Case of Payre, France

Abstract

There appears to be little doubt as to the existence of an intentional technological resolve to produce convergent tools during the Middle Palaeolithic. However, the use of these pieces as pointed tools is still subject to debate: i.e., handheld tool vs. hafted tool. Present-day technological analysis has begun to apply new methodologies in order to quantify shape variability and to decipher the role of the morphology of these pieces in relation to function; for instance, geometric morphometric analyses have recently been applied with successful results. This paper presents a study of this type of analysis on 37 convergent tools from level Ga of Payre site (France), dated to MIS 8–7. These pieces are non-standardized knapping products produced by discoidal and orthogonal core technologies. Moreover, macro-wear studies attest to various activities on diverse materials with no evidence of hafting or projectile use. The aim of this paper is to test the geometric morphometric approach on non-standardized artefacts applying the Elliptical Fourier analysis (EFA) to 3D contours and to assess the potential relationship between size and shape, technology and function. This study is innovative in that it is the first time that this method, considered to be a valuable complement for describing technological and functional attributes, is applied to 3D contours of lithic products. Our results show that this methodology ensures a very good degree of accuracy in describing shape variations of the sharp edges of technologically non-standardized convergent tools. EFA on 3D contours indicates variations in deviations of the outline along the third dimension (i.e., dorso-ventrally) and yields quantitative and insightful information on the actual shape variations of tools. Several statistically significant relationships are found between shape variation and use-wear attributes, though the results emphasize the large variability of the shape of the convergent tools, which, in general, does not show a strong direct association with technological features and function. This is in good agreement with the technological context of this chronological period, characterized by a wide diversity of non-standardized tools adapted to multipurpose functions for varied subsistence activities.

The application of 3D modeling and spatial analysis in the study of groundstones used in wild plants processing

“…The relative position in 3D space of the points is then determined through triangulation (Luhmann et al 2013;Porter et al 2016). Both techniques give the possibility to produce highresolution 3D models, which can be used in geometric morphometric analysis of stone tools (Bretzke and Conard 2012;Chacòn et al 2016;Grosman et al 2008;Morales et al 2015), percussion tools (e.g., Caruana et al 2014;Benito-Calvo et al 2015), and cutmarks on bone surfaces (Arriaza et al 2017;Maté-González et al 2018;Maté-González et al 2017). For the purpose of this study, we adopted the photogrammetric technique, following the methodological framework proposed by Porter et al (2016) to produce accurate 3D models of the experimental groundstones before and after use.…”

A Comparison of Châtelperronian and Protoaurignacian Core Technology Using Data Derived from 3D Models

“…These functions produce a series of elliptical Fourier descriptors, which can be investigated using several statistical methods. Elliptical Fourier analysis has previously been used in lithic analysis to look for patterns in the shape of flakes (Chacón et al 2016, Picin et al 2014, unifacial points (Iovita 2011) and bifaces (Fox 2015;Iovita 2010;Iovita and McPherron 2011;Putt et al 2014;Sholts et al 2012). To our knowledge, this method has only previously been applied to the shape of lithic artifacts from above in plan view, but not in cross section.…”

“…Abel et al 2011;Buchanan & Collard 2010;Clarkson & Hiscock 2011;Lin et al 2010;Magnani 2014;Morales et al 2015;Porter et al 2016;Shott 2014). Researchers have also begun to take advantage of techniques such as geometric morphometrics and landmark analysis (Archer et al 2018;Davis et al 2015;Lycett et al 2006;Lycett & von Cramon-Taubadel 2013;Shott & Trail 2010), attribute-based principal components analysis (Scerri 2013), elliptical Fourier analysis (Chacón et al 2016;Fox 2015;Iovita 2010;Iovita 2011;Iovita & McPherron 2011;Picin et al 2014;Putt et al 2014;Sholts et al 2012), vector analysis (Bretzke & Conard 2012;Clarkson et al 2006), and scar density analysis (Shipton and Clarkson 2015).…”

Exploiting 3d Multispectral Texture for a Better Feature Identification for Cultural Heritage

“…Virtual 3D models also help restoration field to virtually restore an object or formulate a hypothesis of how the object looked (Acke et al, 2018;Arbace et al, 2013;Hawotte, 2014;Zhao et al, 2018). It can be used in science for morphometrics (Chacón et al, 2016;Selden et al, 2014) or a comparison of similar objects in different museums or countries.…”