Monkey Tools

By using stones to break open nuts, monkeys accidentally create sharp-edged flakes that look like the tools believed to have been used by our ancient human relatives.
The finding casts doubt on whether all the stone flakes found in archaeological digs really are the tools of early hominins — and raises the possibility that they might be accidental by-products of hitting things with whole stones, says Lydia Luncz at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. 
Stone flakes made by monkeys cast doubt on ancient human 'tools'