Forty-one millennia ago, deep inside a Belgian cave, Neanderthals left behind a disturbing legacy. Mixed in with the scattered remains of horses and reindeer lay fragments of their own kind -- bones split for marrow and scored by stone blades.
A study published in Scientific Reports sheds new light on this grisly scene. The remains belonged to six individuals who were butchered with surgical precision. According to Quentin Cosnefroy, a biological anthropologist at the University of Bordeaux, the victims weren't random.
Cosnefroy's team reexamined more than a hundred bone fragments from the Goyet cave system. This site was once dismissed as unremarkable, but we now know it hosts some of the most remarkable Neanderthal remains. Their analysis found that nearly one-third of the human bones bore unmistakable cut marks and impact fractures -- clear evidence of defleshing and marrow extraction. These were not injuries sustained in life, but stuff that happened afterward.
Microscopic analysis revealed an even darker detail: some of the bones were subsequently used as tools. This behavior has been seen at other Neanderthal sites, like Moula-Guercy in France, but the clarity here is striking. The authors noted "fresh bone fractures" and cuts that indicate the bodies were processed while the bone was still fresh. Neanderthals butchered, ate, and then used the remains of their own kind.
The victims included four females (adult or adolescent), a young boy, and a baby. While they weren't related to one another, isotopic signatures in their teeth revealed they all came from the same region and ate similar diets rich in animal protein.
However, the adults were unusually small -- standing only around 150 centimeters (4'11") tall -- and lightly built. They lacked the thick, muscular reinforcement typical of most Neanderthals.
"At a minimum," the researchers concluded, "it suggests that weaker members of one or multiple groups from a single neighboring region were deliberately targeted."
It's not the first time cannibalism in Neanderthals was presented. Similar evidence has surfaced in Croatia and Spain. However, the Goyet case stands out for its methodical nature. The perpetrators hunted and then consumed members of their own species.
The authors describe this as exocannibalism -- the eating of outsiders, usually tied to conflict or dominance. Ethnographic studies show that groups often practice exocannibalism during warfare, killing and partly eating enemies to demonstrate power.
The study's results align with that pattern. The victims were locals to the region, yet their skeletons lacked signs of extensive travel. Their captors likely seized and killed them near the cave.
This act of cruelty apparently had no limits. The attackers spared no one. Archaeologists found cut marks on a juvenile's collarbone, evidence of butchering. The infant's femur, though unmarked, was found tossed among the processed remains.
The study doesn't include humans, but our ancestors' influence was probably there. In fact, they may have had something to do with this endless violence.
Around 45,000 years ago, Homo sapiens began arriving in Europe, encroaching on regions not far from Goyet. Their presence likely intensified competition for resources, pushing isolated Neanderthal groups into conflict.
"Demographic pressure and group competition might have surged in the region," the authors wrote.
It's not entirely impossible humans were actually the ones who ate the Neanderthals, though Cosnefroy's team leans toward Neanderthal-on-Neanderthal violence. The key evidence is the "bone retouchers" -- human bones reused to sharpen stone tools. Archaeologists have found these almost exclusively at Neanderthal sites.
Whatever was the case, the Goyet cave paints a grim picture of a species nearing its expiration date. By 40,000 years ago, Neanderthals had all but vanished from Europe, leaving behind only scattered traces of their lives.
Their world was shrinking. Cold climates, scarce prey, and the advance of Homo sapiens cut Neanderthal groups off from one another. Cultural differences among Neanderthal groups may have deepened divides, leading to conflict. The cannibalized bones at Goyet, the authors suggest, "represent the most compelling evidence to date for inter-group competition among Late Pleistocene Neandertal populations".