Like Ancient Humans, Capuchin Monkeys Made Stone Tools Too

One of the pillars of human technology is the creation of stone tools. However, a new study reveals that human beings are not the only creatures on Earth that could yield these tools. Archeologists in Brazil reveal that bearded capuchin monkeys can make these tools too.

The study, published in the journal Nature, refutes previously acclaimed assumptions that the creation of stone tools is a distinct Homo skill set which has been used to trace ancient humans in the absence of fossils.

The study observed that bearded capuchin monkeys (Sapajus libidinosus) at the Serra da Capivara National Park in Brazil have a behavior of hitting a stone to quartz cobbles, which chips off parts of the stone, creating sharply pointed tools called stone flakes.

"In terms of a technique of making flakes, this is a very similar technique to what has been hypothesized was the technique to make the very earliest archaeological flakes," Tomos Proffitt, an archaeologist at the University of Oxford, told CS Monitor.

"It's an incredibly interesting behavior. Another species is making sharp, conchoidally fractured flakes, an artifact that we only ever thought is unique to hominins," he added.

This discovery shows that the production of these archaeological stone tools, which are vital to human history, is no longer unique to the human lineage. Proffit says that the tools made by capuchin monkeys could easily pass as Hominin-made stone tools to the naked eye.

To further attest this claim, in July 2011, archeologists Sonia Harmand and Jason Lewis of Stony Brook University have unearthed stone tools that are significantly older than our genus.

In an interview with Discover Magazine, Harmand reveals that their local guide in Kenya's Lake Turcana spotted stone tools that are sticking out of an eroding creek bed. Upon closer observation, Harmand observed that the said tools dated more than 2.7 million years ago as evidenced by the layers of sediment they were embedded from.

Using paleomagnetic dating, the archaeologists determined that the stone tools were made 3.3 million years ago, which are older than Oldowan, the earliest known stone tool assemblage at 2.6 million years old found in Gona, Ethiopia.

Meanwhile, paleoanthropologist John Shea of the Brook University, who is not a part of the study, says the capuchin monkey-made stone flakes' similarity to ancient human-made stone flakes is because stone fractures could easily be produced by simply hitting rocks. What makes the two different is the purpose of making them.

"They're producing objects that are visually similar to the most distinctive component of human stone tool technology. Humans use the flakes to cut things, capuchins don't," he said.