Archaeologists digging in a Sri Lankan cave have found what appears to be the oldest evidence of bow-and-arrow use outside of Africa: 48,000-year-old arrowheads crafted from animal bone.
Previously, the earliest evidence of bowhunting in Southeast Asia dated to 32,000 years ago. Older still are traces of 64,000-year-old bow-and-arrow technology discovered in South Africa, reports Ashley Strickland for CNN.
Excavations in and around the rainforest cave of Fa-Hien Lena produced a total of 130 bone arrow tips, 29 bone tools likely used on animal skins and plant fibers, and several shell beads, the researchers write in the journal Science Advances. The bone implements may offer evidence that the cave’s inhabitants made and wore clothes—an innovation typically associated with humans living in colder parts of the world, according to a statement.
“Most of these tools were made out of monkey bone, and many of them appear to have been carefully shaped into arrowheads,” lead author Michelle Langley, an archaeologist at Griffith University in Australia, tells Tim Vernimmen of National Geographic. “They are too small and light to have been spearheads, which need some weight to gain force, and too heavy and blunt to have been blow darts.”
To zero in on the role these carefully shaped points of bone played, the researchers examined them using microscopes. The analysis revealed cracks and damage consistent with use as high-speed projectiles, according to Science News’ Bruce Bower. Additionally, the team determined that many of the tips bore notches and wear patterns that indicate they were once fastened to thin shafts.
Speaking with National Geographic, Langley posits that these ancient humans’ bows “would have been made from perishable plant materials” that rotted away long ago. Many of the tools, including the proposed arrow points, were made of monkey bone, leading the researchers to suggest that Fa-Hien Lena’s inhabitants actively hunted primates.
Marlize Lombard, an archaeologist at the University of Johannesburg who wasn’t involved in the study, tells Science News she is holding out on making a determination on the bones until they undergo a high-resolution CT scan. This technology can offer insights on materials’ internal structure and has previously been used to identify tell-tale signs of impact in other ancient arrowheads.
Ryan Rabett, an archaeologist at Queen’s University Belfast who also wasn’t involved in the study, tells Science News that the paper’s interpretation of the bone points is “suggestive but not definitive.” He notes that the points could have been used as part of a pronged fishing spear—a theory supported by the discovery of fish bones at the site.
Regardless of whether the bone points are indeed arrows, they were part of a toolkit used by ancient humans to survive in the rainforest’s challenging environment. Though the largest human migration out of Africa occurred around 60,000 years ago, according to National Geographic, smaller factions made their way to Southeast Asia around 70,000 years ago and dispersed into Australia within the next 5,000 years.
Study co-author Oshan Wedage, an archaeologist at the University of Sri Jayewardenepura in Sri Lanka, tells National Geographic that the first humans to arrive on the island probably stayed near the coast.
“But as the population grew,” he adds, “some of their descendants may have moved into the rainforest.”
Innovations such as clothes and bow-and-arrow hunting would certainly have helped humans adapt to the rigors of jungle life. As Wedge explains, these ancient people may have worn clothing to protect against mosquitoes and other biting insects. Bowhunting, meanwhile, was well-suited for killing agile prey like monkeys.
“A spear isn’t particularly useful for catching a monkey or a squirrel in a forest,” Langley tells National Geographic. “[Y]ou need something that’s swift and that can go high.”
Speaking with Science News, Justin Pargeter, an archaeologist at New York University who wasn’t involved in the study, adds a final twist to the artifacts’ story, suggesting they may not have been made by anatomically modern humans. Researchers haven’t found hominid remains the cave, and around the time of the tools’ creation, Homo sapiens were living alongside Neanderthals and Denisovans in Asia and the Pacific islands.
“It may be too soon to conclude that this story is all about ‘modern’ humans,” says Pargeter.