Black-striped capuchin
Sapajus libidinosus
The black-striped capuchin is a capuchin monkey from South America. It was the first non-ape primate in which tool usage was documented in the wild, as individuals have been seen cracking nuts by placing them on a stone "anvil" while hitting them with another large stone. Adaptations to carrying large stones and fruit include strengthened back and leg muscles that permit the monkey to walk on its hind legs while carrying stones.