New research has suggested that Belgian Neanderthals were eating each other about 40,000 years ago. The gruesome discovery was made when scientists found bones bearing marks left by intentional butchering. The discovery suggests that Neanderthals were not only cannibals but they even made tools out of the bones of their own kind.

The Neanderthals lived in western Asia and Europe for thousands of years and were a human subspecies. They became extinct around 30,000-40,000 years ago. Homo sapiens, our ancestors, may have arrived while the Neanderthals were slowly disappearing.

When it comes to Homo sapiens’ sexual history, they were much more adventurous than previously realised. Humans’ sexual adventures have left an indelible mark on the human genome. Neanderthals were not as lucky as humans when it came to survival in the long run. However, it did not stop the two from having sex and making babies.

Evidence suggests that humans and Neanderthals interbred and it is believed that up to four percent of the DNA of Asians and Europeans was derived from them. The unions also had an effect on the immune systems and metabolisms of the babies born. Humans made more babies with archaic human-like species than initially thought.

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The new research, published in the journal Nature Scientific Reports, uncovered bones from the Goyet caves near Namur in Belgium. The bones bore notches, pits and cut marks, signifying butchery. Moreover, it appears to be a thorough process with evidence found of extraction of bone marrow, cutting up and skinning.

“These indications allow us to assume that Neanderthals practised cannibalism ... The many remains of horses and reindeer found in Goyet were processed the same way,” lead scientist professor Herve Bocherens from the University of Tubingen in Germany said in a press release.

Neanderthal cannibalism was hinted previously as clues emerged in France and Spain. However, four bones discovered in Goyet is evidence that the subspecies not only ate their own kind but also used their bones as tools. Three shin bones and one thigh bone were used to shape stone implements. The Neanderthals used animal bones as knapping tools.

The new findings have opened up possibilities as regards the way late Neanderthals dealt with their dead before they slowly became extinct. Bocherens revealed that no other Neanderthal site in the region except that of Goyet indicated the dead being dealt that way.

“The big differences in the behaviour of these people on the one hand, and the close genetic relationship between late European Neanderthals on the other, raise many questions about the social lives and exchange between various groups,” Bocherens added.