Understanding edge angle variability and morpho-functional design of Late Middle Palaeolithic Keilmesser assemblages

<b>Understanding edge angle variability and morpho-functional design of Late Middle Palaeolithic Keilmesser assemblages </b> The Late Middle Palaeolithic <i>‘Keilmessergruppen’<i> (KMG) assemblages of Central and Eastern Europe are characterised by asymmetrically backed tools. Most of these items are bifacially worked, produced in a highly standardised mode and display characteristic wedge-(‘Keil’)-shaped sections. Due to their single working edge these tools have been interpreted as knives. In Keilmesser, long reduction sequences have repeatedly been documented (Jöris 2006), allowing for detailed morpho-technological reconstructions of their use-life histories, including repetitive phases of production, usage, re-sharpening and re-use. </i></i><i><i> </i></i> Due to the aforementioned characteristics, Keilmesser provide a unique archive for tracing certain features of late Neanderthal behaviour. These may range from understanding tool dedication, function and its underlying design and production concept, learning strategies, technical innovations, the transmission of ideas and knowledge to the formation of late Neanderthal regional traditions. At some KMG sites, Keilmesser frequently display the application of tranchet blows that sharpens the working edge at the tip of the tool through removing the lateral edge. The use of this method (within KMG contexts called <i>‘Prądnik method’<i>) reflects intentional design and puts special emphasize on the edge angle near the tool-tip. This observation implies a certain hierarchization of different parts of the working edge within the same tools that might be related to its use-life. Various interpretations consider the application of this method as e.g. tool-finishing or as maintenance, sharpening or optimization of an existing working edge. Nevertheless, which effect it has remains so far speculative. </i></i><i><i> </i></i> In order to address these aspects, here we apply a particular methodology, which includes - among others - 3D scanning to acquire the measurements and for morphometric analyses (Grosman <i>et al.<i> 2008). To obtain a more distinct picture of the working edge a sample of Keilmesser made of silicified schist is used as a case study. Our study aims at an improved understanding of how the working edge of a Keilmesser was actually designed and which effects specific edge angles might have had. Targeted objective and quantitative use-wear analyses (Marreiros <i>et al.<i> 2015) on the material will supplement this study. </i></i></i></i><i><i><i> </i></i></i> By including controlled experiments, 3D morphometric data analysis as well as macro and micro use-wear analysis, this approach will provide new data that aim to test the given interpretations of these asymmetrically backed tools from the Late Middle Palaeolithic. Hence, this research will contribute to a more holistic understanding of the concepts underlying tool design, function and its realisation.