Neanderthals that walked the Earth tens of thousands of years ago butchered the bodies of other Neanderthals, leaving behind evidence of both cannibalism and bone tool-making, researchers from a German university report.

The 99 bones came from a cave in Goyet, Belgium, and experts were able to date them to be between 40,500 and 45,500 years old. Genetic analysis of the ancient species’ mitochondrial DNA shows that the Neanderthals represented by the bones were related to each other closely.

But most interesting is the markings on the bones, which show evidence of butchering. According to a statement released by the University of Tübingen in Germany, it’s the “cut marks, pits and notches” found on the bones that suggest the butchering and point toward cannibalism. Not only that, the scientists found evidence of “skinning, cutting up, and extraction of the bone marrow” from the remains, according to the University of Tübingen.

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“These indications allow us to assume that Neandertals practised cannibalism,” Hervé Bocherens, a professor at the University of Tübingen and coauthor of a new study announcing the results, said in the statement. He also said that the butchering could have been not for food, but part of a ritual.

In addition, the researchers discovered evidence that Neanderthals used bones from their same species as tools, which were employed in turn to modify stone tools. Three shinbones and a thigh bone functioned as tools, the scientists report. Bocherens said that it’s rare to see such bone tools made from Neanderthals.

Neanderthals went extinct about 30,000 years ago.

The study of cannibalism and bone tools is published in the journal Scientific Reports.

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