Wild Chimps Rocked On: Apes left unique record of stone tools

Archaeologists, by definition, uncover the remnants of past human activity. With the first excavation of chimpanzee stone tools at an African site, however, the scope of their work has entered virgin terrain.

Chimps transported suitable pieces of stone to the undated site and used them to crack open nuts placed on thick tree roots, according to Julio Mercader of George Washington University in Washington, D.C.