Tools believed to have been created by ancient humans were actually made by monkeys

Photo: NELSON ALMEIDA/AFP/Getty Images

A study led by researchers from the National Scientific and Technical Research Council (CONICET) of Argentina showed that 50,000 year old tools -identified long ago in the “Pedra Furada” cave, in the northeast of Brazil- were made by ancestors of capuchin monkeys and not by humans, as was thought.

According to the study, one of the hottest debates in American archeology has to do with the time when the first humans entered the continent. Most researchers agree that the first Americans (Homo sapiens sapiens) would have arrived between 13,000 and 14,000 years before present, crossing the Bering Strait, which connects Asia with North America.

However, a group of specialists working in Brazil proposes that the American peopling would have been much older, possibly between 20,000 and 50,000 years before the present, and to confirm it, they maintain, among other arguments, that the tools found in the “Pedra Furada” cave and other deposits in the northeast of Brazil are of human origin.

To prove or refute this hypothesis, the archaeologist Agustín Agnolín and the paleontologist Federico Agnolín, CONICET researchers decided compare stone tools found at Pedra Furada (supposedly from the first Americans) and those made today by capuchin monkeys.

“The result was surprising: there were no differences between the supposed human tools of 50,000 years ago and those produced by monkeys today”, says A. Agnolín, a researcher at the Institute of Latin American Anthropology and Thought (INAPL).

This is how monkeys create and use their tools

The CONICET study coincides with other very recent studies carried out in Brazil that show that capuchin monkeys use rock tools. They go to quarries of rounded rocks, known as “boulders”, and there they select a rock that they consider to be of adequate size and use it as a hammer together with another larger one that is flattened as an anvil to crack nuts. They also use tools to dig and get food.

“In other cases, capuchin monkeys hit one rock with another and then they lick the dust that is generated after the blows, possibly as a way of obtaining minerals that are scarce in their diet. The result is that the rocks used tend to break, generating rock fragments very similar to those produced by humans when carving stone tools”, explains A. Agnolín.

In addition, A. Agnolín points out that the found tools at Pedra Furada and other deposits in the Northeast of Brazil they are extremely simple in their manufacture and that they have never been done on rocks from other places.

“Our study shows that the tools at Pedra Furada and other nearby deposits in Brazil were nothing more than the product of capuchin monkeys cracking nuts and rocks some 50,000 years before the present”, affirms F. Agnolín, also a researcher at the “Bernardino Rivadavia” Argentine Museum of Natural Sciences’ (MACN-CONICET), and the “Azara Foundation”.

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