The Stone Age has not only been inhabited by humans. One more person in the club?
Given that they use rocks as instruments, bearded capuchins are in a “stone age” of their own. Here, a grizzled capuchin uses a stone to split open a coconut. A stone in a coconut.
Many creatures use rocks as tools, including ants(opens in new browser), fish(opens in new tab), and crows(opens in new tab). But until lately, only humans and our hominin cousins had a known archaeological record of stone tool use. The scientific world now recognizes the presence of other hominins. Which animals, then, have supposedly reached their own “stone age” in terms of archaeology?
The Stone Age isn’t the most exclusive society, it turns out. Long-tailed macaques, capuchin monkeys, and chimpanzees have also joined the group; archeological remnants now show that they once used stone implements. Then there might be sea otters(opens in new browser).
The use of tools is a socially taught habit in all primate species. Katarina Almeida-Warren(opens in new tab), a chimpanzee researcher at the University of Oxford, said that it has become a part of their society. Different organizations employ various instruments. According to Almeida-Warren, some chimpanzee communities, for instance, use a “hammer” boulder placed on a “anvil” rock to crush nuts.
For thousands of years, chimpanzees (Pan troglodytes) have used hammer and anvil implements. Chimpanzees in the Ivory Coast used these tools 4,300 years ago, according to study that was published in 2007 in the magazine Proceedings of the National Academy of Sciences(opens in new tab). The experts concluded in their study that “the ‘Chimpanzee Stone Age’ predates the emergence of established agricultural communities in this section of the African jungle.
Stone nut-cracking tools have been found to have been used by capuchin primates (Sapajus libidinosus) as far back as 3,000 years ago in Brazil. According to research published in the journal Nature Ecology and Evolution, their tool designs evolved over millennia in reaction to various diets.(opens in new tab).
Then, a crew discovered stone tools that had once been used to crack open shells by Burmese long-tailed macaques (Macaca fascicularis aurea) on a seashore in Thailand. According to a 2016 article in the Journal of Human Evolution, these instruments were probably used between 1950 and 2004.
The origin of these animals’ stone instrument use is unknown. Early stone tools indicate that chimpanzees’ “percussive material culture” was passed down by a shared progenitor of humans and chimpanzees, according to the study’s authors. Although it seems to be the case with the other animals known to use stone tools, it’s also conceivable that humans and chimpanzees developed their skill separately of one another.
Tiago Falótico, a scientist and primatologist at the University of So Paulo and a co-author of the capuchin tools study, said of stone tools, “They have this aura. He told Live Science that going back to a “stone age” does not necessarily indicate that a group will shortly follow the path of humanity. It also doesn’t mean that people who use stone tools are inherently more intelligent than people who use animal tools. Falótico said, “You can have the same reasoning with stones, timber, or leaves.
The study community values stone instruments instead because of how durable they are. Archaeologists and scientists must take into account the possibility that primate artifacts may turn up in digs. Who did what is a hot topic of discussion, according to Almeida-Warren.
According to study released in the journal The Holocene in 2022, a team from Argentina proposed that 50,000-year-old “human settlements” in Brazil were actually made by capuchin monkeys.(opens in new tab). The experts discovered that the stone tools in issue, which were fashioned from quartzite and quartz cobbles, are remarkably identical to those produced today by capuchin monkeys in Brazil’s Serra da Capivara National Park.
Falótico wrote to Live Science in an email to say, “That paper is far from being conclusive.” He added that further empirical investigation is still required. But if accurate, the theory would add a significant amount of time to the historical stone tool record of the capuchins and keep the question of when humans first inhabited South America open.
Nonhuman made tools can provide information to human archaeologists in other ways even when it is obvious which tools pertain to which species. Primate tools offered archaeologists new ideas about what to look for, according to Almeida-Warren, who claimed that the earliest hominin-made tools, dating from 3.3 million years ago(opens in new tab), were discovered in part as a result. It sort of opened the door for these other entities to flourish, she said.
Almeida-Warren noted that although the human Stone Age was called after the implements that persisted, people “weren’t just using stones” during this time. Other “stone age” animals don’t either. Researchers can envision human tools that have long since decayed by studying other tools used by animals today.
Chimpanzees, for example, use long pieces of bark to fish for termites, Almeida-Warren said; they also use medicinal plants to treat wounds. “In many cases,” she said, “the plant tools are actually more complex.”
Nonhuman archaeology can provide insight into the historical actions of these animals. Falótico discovered, for instance, that the primates modified their tools over time to prepare various foods at the old capuchin sites. Next, scientists want to shed light on the past of marine otters, another species that used tools.
Sea otters have been seen by researchers in California smashing open mussels on boulders.(opens in new tab). In a 2019 study published in the journal Scientific Reports(opens in new tab), researchers were able to tell human traces from scratches on the sea otters’ “anvil” pebbles.
The West Coast of North America’s kelp ecosystems have changed due to sea otter population decreases. Researchers expect to reconstruct the past of otter communities and the ecosystems they have impacted now that they are aware of what to look for.
