Earliest tool use by chimpanzees

The earliest known use of tools by chimpanzees Pan troglodytes dates back 4,300 years, when chimpanzees were using pieces of stone as hammers to smash nuts in the rainforest of the Ivory Coast (Côte d'Ivoire), western Africa. The chimp tools were discovered when a team of scientists from Canada's University of Calgary featuring Dr Julio Mercador dug out a 4,300-year-old archaeological Panin site in the Ivory Coast's Tai National Park. Some Stone Age human tools were also present at this site, but the chimp ones were readily distinguished by being larger and more primitive in form, and by containing nut-derived starch grains lodged in the crevices of the tools' edges (whereas those made by humans contained legume or tuber fragments instead; humans here at that time did not eat nuts).