Oxford University researchers have uncovered an archeological trove of stone tools used by capuchin monkeys in Brazil in the 14th century to open cashew nuts. These simians still use the tool. It can be found by cashew trees in the Serra da Capivara National Park, in the state of Piaui. The apes use a large stone as an anvil, upon which they place the cashew nuts. They then crack it open with a smaller stone. The capuchin monkeys have become so skilled at the task that they do not injure themselves, unlike chimpanzees using similar tools. Researchers wonder if humans learned of the fruit thanks to the monkeys. The shell, covered in toxic resin that can cause sickness, disguises well its content. From the outside, it does not seem to contain an edible fruit. More importantly, this finding adds yet another question mark to our classical notions of intelligence. The tweak now is that it may recast also another discipline: History. This evidence points to the onset of a Stone Age for the Brazilian capuchin monkeys. A question arises: How fast is evolution proceeding?