Amputation 31,000 years ago, among the prehistoric artists of Borneo.

Science magazine recently covered the tale archaeologists uncovered about one of the earliest known settlers of Borneo, a young hunter-gatherer who had an injured foot amputated … thousands of years before the invention of modern antibiotics and anaesthesia:

The find traces to early 2020, when a team of Australian and Indonesian scientists excavated the floor of a cave called Liang Tebo in a remote, densely forested region of eastern Borneo. “There are absolutely no settlements, no telephone signal, no electricity,” says team member Andika Arief Drajat Priyatno, an archaeologist at the East Kalimantan Cultural Heritage Preservation Center.

As workers, including Andika and others, scraped away a section of cave floor inch by inch, they discovered a remarkably intact human skeleton reclined in a kneeling position, with stones positioned above its head and hands, as if they were grave markers. The individual, whose sex could not be determined from their bones, was in their early 20s when they died. A small chunk of ochre, a natural pigment, was buried near the person’s face. That hints that they may have created some of the markings on the cave walls, says the study’s senior author, Maxime Aubert, a geochemist and archaeologist at Griffith University, Gold Coast, in Australia.

When the skeleton was fully revealed, the researchers noticed it was missing the bottom of its left leg from about the middle of the shin downward. The shin bones had fused at the bottom—a clear sign of healing following a traumatic injury, explains co-author Melandri Vlok, a bioarchaeologist at the University of Sydney.

When the scientists returned the following year, Vlok noticed the end of the leg was cut cleanly in a straight line, with no sign of crushing or shattering, as expected if a rock had fallen on it or an animal had bitten it off. “It looks exactly like what you would expect if a sharp blade cut completely perpendicular to the bone,” she says. “It made us confident this was surgery.”

The team can’t say why ancient surgeons amputated the Borneo limb—whether because of disease or traumatic injury. Based on the degree of fusing of the shin bones, the individual lived and grew for another 6 to 9 years, Vlok says. The cause of death is unclear.

You can read more of the team’s research here, in Nature.