A Non-Destructive Method for Distinguishing Reindeer Antler (Rangifer tarandus) from Red Deer Antler (Cervus elaphus) Using X-Ray Micro-Tomography Coupled with SVM Classifiers.

Over the last decade, biomedical 3D-imaging tools have gained widespread use in the analysis of prehistoric bone artefacts. While initial attempts to characterise the major categories used in osseous industry (i.e. bone, antler, and dentine/ivory) have been successful, the taxonomic determination of prehistoric artefacts remains to be investigated. The distinction between reindeer and red deer antler can be challenging, particularly in cases of anthropic and/or taphonomic modifications. In addition to the range of destructive physicochemical identification methods available (mass spectrometry, isotopic ratio, and DNA analysis), X-ray micro-tomography (micro-CT) provides convincing non-destructive 3D images and analyses. This paper presents the experimental protocol (sample scans, image processing, and statistical analysis) we have developed in order to identify modern and archaeological antler collections (from Isturitz, France). This original method is based on bone microstructure analysis combined with advanced statistical support vector machine (SVM) classifiers. A combination of six microarchitecture biomarkers (bone volume fraction, trabecular number, trabecular separation, trabecular thickness, trabecular bone pattern factor, and structure model index) were screened using micro-CT in order to characterise internal alveolar structure. Overall, reindeer alveoli presented a tighter mesh than red deer alveoli, and statistical analysis allowed us to distinguish archaeological antler by species with an accuracy of 96%, regardless of anatomical location on the antler. In conclusion, micro-CT combined with SVM classifiers proves to be a promising additional non-destructive method for antler identification, suitable for archaeological artefacts whose degree of human modification and cultural heritage or scientific value has previously made it impossible (tools, ornaments, etc.).

Circulation of whale-bone artifacts in the northern Pyrenees during the late Upper Paleolithic.

The importance of coastal resources in the late Upper Paleolithic of western Europe has been reevaluated in recent years thanks to a growing body of new archeological evidence, including the identification of more than 50 implements made of whale bone in the Magdalenian level of the Isturitz cave (western Pyrenees). In the present study, the assemblages of osseous industry from 23 Magdalenian sites and site clusters in the northern Pyrenees were investigated, systematically searching for whale-bone implements. The objective of this research was to determine if, and how, tools and weapons of coastal origin were circulated beyond Isturitz into the inland, and if similar implements existed on the eastern, Mediterranean side of the Pyrenees. A total of 109 whale-bone artifacts, mostly projectile heads of large dimensions, were identified in 11 sites. Their geographic distribution shows that whale bone in the Pyrenean Magdalenian is exclusively of Atlantic origin, and that objects made of this material were transported along the Pyrenees up to the central part of the range at travel distances of at least 350 km from the seashore. This phenomenon seems to have taken place during the second half of the Middle Magdalenian and the first half of the Late Magdalenian, ca. 17,500-15,000 cal BP (calibrated years before present). The existence of a durable, extended coastal-inland interaction network including the circulation of regular tools is thus demonstrated. Additionally, differences between the whale-bone projectile heads of the Middle Magdalenian and those of the Late Magdalenian document an evolutionary process in the design of hunting weapons.

From flakes to grooves: a technical shift in antlerworking during the last glacial maximum in southwest France.

The evolution of antlerworking technology in Paleolithic and Mesolithic Europe, especially the production of splinters, is usually described as a cumulative process. A progressive increase in blank standardization and productivity was prompted by the application of a key technical process, the groove and splinter technique (GST). The Badegoulian, however, appears as an interruption in this continuum. According to the original definition of this post-Solutrean, pre-Magdalenian archeological culture, one of its distinctive features is the absence of the GST and the manufacture of antler blanks by knapping only. However, this conception has been recently questioned, leading to an alternative hypothesis suggesting that both GST and knapping were used during the Badegoulian. In this article, we present new evidence from several sites in southwest France, which sheds new light on the issue of Badegoulian antlerworking and the transition with the subsequent Lower Magdalenian. Our study is based on two complementary methods: the technological analysis of antler assemblages well-dated to the Badegoulian (Le Cuzoul de Vers) or to the Lower Magdalenian (La Grotte des Scilles, Saint-Germain-la-Rivière), and the direct (14)C dating of specific antler artifacts from mixed or problematic contexts (Cap-Blanc, Reverdit and Lassac). The results firmly establish that, in southwest France, knapping is the only method used for the production of antler splinters during the Badegoulian, before ca. 20,500 cal BP (calibrated years before present), and that it is rapidly replaced by the GST at the beginning of the Lower Magdalenian, after ca. 20,500 cal BP. This technical shift is not linked to an influx of new human populations, environmental change or the supposed economic advantages of the GST. Instead, it must be understood as one of the expressions of a broader reconfiguration of the technical world that starts to take shape in the middle of the Last Glacial Maximum.