The Lichtenberg Keilmesser - it's all about the angle.

The presence of the 'Keilmesser-concept' in late Middle Paleolithic assemblages of Central and Eastern Europe defines the eponymous 'Keilmessergruppen'. The site of Lichtenberg (Lower Saxony, Germany) was discovered in 1987 and yielded one of the most important Keilmessergruppen assemblages of the northwestern European Plain. At that time, researchers used the bifacial backed knives to define a new type, the 'Lichtenberger Keilmesser', which they characterized by an aesthetic form-function concept with a specific range of morphological variability on the one hand, and a standardized convex cutting edge one the other hand. Thereby, a shape continuum was observed between different form-function concepts in the Lichtenberg assemblage, from Keilmesser through to Faustkeilblätter and handaxes. In a contrasting view, it was recently suggested that the morphology of Keilmesser, including what is defined here as type Lichtenberg, is the result of solutions to establish and maintain edge angles during resharpening. With the intention to evaluate these contrasting hypotheses, I conducted a re-analysis of the Keilmesser from Lichtenberg and their relationship to central German late Middle Paleolithic knives, using 3D geometric morphometric analyses and an automatized approach to measure edge angles on 3D models. Despite a morphological overlap of the tools from both regions, I could show that the Lichtenberg Keilmesser concept refers to one solution to create a tool with specific functionalities, like potentially cutting, prehension, and reusability. To establish and maintain its functionality, certain angles where created by the knappers along the active edges. This behavior resulted in specific shapes and positions of the active parts and created what looks like a standardized or template morphology of this Keilmesser type.