Bearded capuchin monkeys may be the new revelation in the scientific community, as researchers have recently discovered that the animals can create tools.
"They never use the flakes, they don't care about them", study researcher and primate archaeologist Tomos Proffitt, from the University of Oxford, said. In light of this recent remarkable discovery, however, we can only beg the question: Were all of those tools made by human ancestors? . The observation is important because the creation of stone flakes with characteristics that enabled them to be used as tools is considered a trait unique to humans and our closest ancestors, the hominins.
But here's the catch: In the monkeys, the flake production seems to be the unintentional result of another behavior. "Another species is making sharp, conchoidally fractured flakes, an artifact that we only ever thought is unique to hominins". So as far as Proffitt's team can tell, the monkeys are not displaying human-like, tool-using behavior. Ancient bones which are etched with hundreds of cut marks found in sites alongside flakes also add weight to the idea that, indeed, human ancestors were using such tools with intent millions of years ago.
After these monkeys struck the stones on rocks, they managed to chip off certain pieces of them which resembled butchery tools.
Proffitt and his co-authors studied capuchin monkeys in the Serra da Capivara National Park.
The team identified complete and broken hammer-stones and complete and fragmented flakes, half of which had "conchoical" fractures where the break is round and smooth in appearance like a shell. As a result, it has been assumed that any unifacial choppers that show up in the archaeological record are the work of early hominins.
"The levels of complexity that we see, even with the earliest hominin stone tool technology, is much more than what is observed with the capuchin material", he said.
"Previous evolutionary explanations for the origins of hominin intentional stone modifications have focused on hominin-specific advances, such as changes in hand shape, coordination and cognitive skills", she wrote in a commentary.
For now, this unexpected research advancement proves a larger point, Rondonine said.
The researchers believe that the capuchins hammer the stones to extract powdered silicon, an essential trace nutrient, or to remove lichen for some unknown medicinal objective.
For more than two decades, wild capuchin monkeys have been observed using stones to break open nuts and perform other tasks, similar to chimpanzees. "The emergence of sharp-edged stone tools that were fashioned and hammered to create a cutting tool was a big part of that story". This, along with the fact that the monkeys do not use the stones as tools, suggests that the mammals are eating lichens or minerals that come from the rocks, Live Science reports.