Photo published on Nature journal

Worn rocks may have been used by Brazilian bearded capuchin monkeys hundreds of years ago, marking the earliest evidence for stone-tool use by a species other than humans or chimpanzees.The oldest stone tools made by ancient human relatives date to 3 million years ago, but the archaeological record for tool use among other primates is scant. Bearded capuchins (Sapajus libidinosus) are known to wield rock anvils to rid cashew nuts of their foul-tasting skin.

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