Monkeys are having their own Stone Age and using tools like humans, breakthrough discovery finds

A species of monkey has been developing stone tools, just like humans did during the Stone Age, scientists have discovered.

Capuchin monkeys have been changing the way they use instruments to eat food, adapting them depending on the hardness of what they are eating.

It is the first time a non-human species has been found to develop technology to suit its diet, in what experts are calling an “archeological milestone”.

The findings, published in the journal Nature Ecology & Evolution, revealed Brazilian capuchins first began using quartz stones to crack open seeds or fruits more than 3,000 years ago.

Capuchin monkeys have developed tools to help them process different foods, much as humans did during the Stone Age. (AFP/Getty Images)

Then around 300 years ago, they began using larger rocks to smash open tougher foodstuffs like cashew nuts.

Scientists from University College London (UCL) and the University of Sao Paulo, made the discovery in a remote part of Brazil’s Serra da Capivara National Park.

Here, they found layers of rounded stones that the monkeys had discarded over the millennia, which served as a record of the primates’ archaeological progress.

The study’s co-author Tomos Proffitt, of UCL, said the discovery was significant because it showed “we as a species are not unique in having a really fine-grained and detailed archaeological record”.

He added: “This capuchin excavation shows that this species of primate in Brazil has its own individual archaeological record; they have their own antiquity to their tool use.”

Other non-human tool sites have been found in other parts of the world – the oldest one being a 4,000-year-old chimpanzee site in Côte d'Ivoire.

However, this is the first time animals have been found to vary their use of stone implements to suit different purposes.

Understanding capuchin tool use could help reveal the origins of the practice in other ape groups, including the earliest members of the human lineage.

The oldest known stone tools – sharpened flint blades – date back 3.3 million years and are attributed to either ‘Australopithecus afarensis’ or ‘Kenyanthropus platyops’, two ancient species of human relatives.

The human Stone Age lasted more than three million years and ended between 8700 BC and 2000 BC.

So if the capuchin monkeys follow a similar evolutionary pattern to humans, they won't be ready to develop nuclear weapons until some point after the year 3,500,000.