The earliest stone tool complex of the Ayacucho Valley, in the central highlands of Peru, which may represent man's earliest presence in South America. Radiocarbon dates of 17,620 BC and 12,730 BC were obtained from sloth bone found in association with crude stone tools and flakes of volcanic tuff. Choppers, bifacial tools, and waste flakes therefore dated between 18,000-12,000 BC.