This contribution presents the results of single and multi-variable osteometric analyses performed on a sample of short bones and phalanxes assigned to Vicugna sp. from Lago Sofía Cave 4 site (13500 – 11000 BP), Región de Magallanes, Chile. The elements analyzed show a similar size to the reference collections for Vicugna vicugna, and do not exceed the metrics for the pampean pleistocenic specimens of Vicugna gracilis. This confirms the morphological and ancient DNA data that indicated the presence of vicuña in southern Chilean Patagonia. The taxonomic, biogeographic and palaeoecologic discussion of these results, suggests that the presence of this species outside its current distribution range was due to shared environmental conditions between the Puna and Patagonia during the Pleistocene-Holocene transition. The extinction of this form is, most likely, due to the impact of climatic change during the begining of the Holocene over its pasturing diet and its territorial and non migratory habits. It is added to this, a hunting pressure by human and non-human predators.