Monkeys made stone tools 50,000 years ago that were discovered in Brazil - study

Stone tools that are estimated to be roughly 50,000 years old were found in Pedra Furada in northeastern Brazil, and that these tools were made by monkeys who lived in that time, according to a study that was first published in November.

The tools found at the sites are characterized "by the use of immediately available raw material," the study says. 

The researchers also state that they're "confident that the early archeological sites from Brazil may not be human-derived but may belong to capuchin monkeys." The peer-reviewed study was published in the journal The Holocene. 

Capucin monkeys are usually found in the tropical forests in Central and South America, according to Heritage Daily. They are considered to be the smartest New World monkey.

Details of the Pedra Furada

The Pedra Furada contains hundreds of archaeological sites that date back thousands of years.

Researchers in the study had compared stone tools from the Pedra Furada to modern capuchin-made stone tool deposits, to which they discovered that the tools from Pedra Furada are consistent with the capuchin-made stone tools.