Muller Antoine, Sharon Gonen, Grosman Leore
Computational Archaeology Laboratory, Institute of Archaeology, Hebrew University of Jerusalem, Jerusalem, Israel.
Multidisciplinary Studies, Tel-Hai College, East Campus, Upper Galilee, Israel.
Sci Rep. 2024 Mar 28;14(1):7422. doi: 10.1038/s41598-024-57450-y.
The edges of stone tools have significant technological and functional implications. The nature of these edges-their sharpness, whether they are concave or convex, and their asymmetry-reflect how they were made and how they could be used. Similarly, blunt portions of a tool's perimeter hint at how they could have been grasped or hafted and in which directions force could be applied. However, due to the difficulty in accurately measuring the complex 3D geometry of tool edges with traditional methods, their attributes are often overlooked. When they are analyzed, they have traditionally been assessed with visual qualitative categories or unreliable physical measurements. We introduce new computational 3D methods for automatically and repeatably measuring key attributes of stone tool edges. These methods allow us to automatically identify the 3D perimeter of tools, segment this perimeter according to changes in edge angles, and measure these discrete edge segments with a range of metrics. We test this new computational toolkit on a large sample of 3D models of handaxes from the later Acheulean of the southern Levant. Despite these handaxes being otherwise technologically and morphologically similar, we find marked differences in the amount of knapped outline, edge angle, and the concavity of their edges. We find many handaxes possess blunt portions of perimeter, suitable for grasping, and some handaxes even possess more than one discrete sharp edge. Among our sample, sites with longer occupations and more diverse toolkits possessed handaxes with more diverse edges. Above all, this paper offers new methods for computing the complex 3D geometry of stone tool edges that could be applied to any number of artifact types. These methods are fully automated, allowing the analysis and visualization of entire assemblages.
石器的边缘具有重要的技术和功能意义。这些边缘的性质——它们的锋利程度、是凹面还是凸面以及它们的不对称性——反映了它们的制作方式以及使用方式。同样，工具周边的钝部也暗示了它们可能的握持或 hafted 方式以及可以施加力的方向。然而，由于用传统方法精确测量工具边缘复杂的三维几何形状存在困难，它们的属性常常被忽视。在对其进行分析时，传统上是用视觉定性类别或不可靠的物理测量来评估的。我们引入了新的计算三维方法，用于自动且可重复地测量石器边缘的关键属性。这些方法使我们能够自动识别工具的三维周边，根据边缘角度的变化对该周边进行分割，并使用一系列指标来测量这些离散的边缘段。我们在来自黎凡特南部阿舍利晚期的大量手斧三维模型样本上测试了这个新的计算工具包。尽管这些手斧在技术和形态上其他方面相似，但我们发现它们在敲击轮廓的数量、边缘角度以及边缘的凹度方面存在显著差异。我们发现许多手斧周边有适合握持的钝部，有些手斧甚至有不止一个离散的锋利边缘。在我们的样本中，居住时间较长且工具包更多样化的遗址拥有边缘更多样化的手斧。最重要的是，本文提供了计算石器边缘复杂三维几何形状的新方法，这些方法可应用于任何数量的 artifact 类型。这些方法是完全自动化的，允许对整个组合进行分析和可视化。
