Geometric morphometrics of large South American camelids and their potential for the taxonomical identification in archaeological sites of the northern Argentina

Abstract

The large South American camelids, the llama (Lama glama) and the guanaco (Lama guanicoe), present a low level of morphological variation in the skeleton and a significant overlap in their body size at population scale. Therefore, if we consider the inter-specific and intra-specific variability, it is difficult to distinguish between wild (guanaco) and domestic (llama) species, based only on osteometric analysis of remains from archaeological sites. Techniques based on 2D geometric morphometric were applied in order to test their power for the taxonomic identification of these two camelids species through shape study of three anatomic elements: the first anterior and posterior phalanges, and the glenoid fossa of scapula. A total of 59 skeletal elements of 29 modern individuals and 14 archaeological specimens were analysed. The morphogeometric evaluation differentiated the skeletal element shapes of modern camelids groups. The archaeological samples revealed the presence of llama and guanaco in the archaeological record of the Argentinean Northwest at 1900-1300 BP. Nevertheless, domestic species were dominant in Antumpa site, whereas wild species were better represented in Condor II. This exploratory study provided an advance in the efforts of taxonomic identification of bone remains from the shape analysis performed on modern individuals of living species.