One way archaeologists learn how ancient people, including Neanderthals, did things is to attempt to do those things themselves, a process called experimental archaeology. Normally, that involves making stone tools, butchering deer, or distilling birch tar. But in a new study, it meant doing very destructive things to teeth from one of the world’s most carefully protected animals.

That’s because the archeologists suspected that Neanderthals once used rhino teeth as tools. By using the teeth to make stone tools, the researchers demonstrated that Neanderthals probably did the same thing, adding to what we know about the wide range of items in their toolkits.

We need to hit some rhino teeth with rocks for science

Some Neanderthal archaeological sites in Europe and Asia seem to have many more rhinoceros teeth lying around than you’d expect. We know Neanderthals hunted a now-extinct species of rhinoceros in Europe and eastern Asia, but the people who had inhabited these sites looked like they had been collecting rhino teeth for some reason.

Depending on the species, a rhinoceros has more than 260 bones but only 24 to 34 teeth. Yet at the 300,000-130,000-year-old cave site of Panxian Dadong in southern China, 74 percent of the rhino remains are teeth, not bones. And teeth make up 91 percent of the rhino fossils at Payre, a rock shelter in southeast France.

Many of those teeth had markings that looked suspiciously like what you’d get from using a piece of bone as a hammer: groupings of shallow pits and overlapping cracks, “produced by the accumulation of blows in the same zone.” There are also thin, shallow scratches from hitting the jagged edge of a stone tool.

To explore whether the markings really were the product of human tool-making and use, though, University of Aberdeen archaeologist Alicia Sanz-Royo and her colleagues needed something to compare them to. Which meant they needed to try their own bone-knapping on actual rhino teeth. But since rhinos are at best a threatened species and trade in rhino parts is heavily regulated under international law, getting those teeth was not easy.