A carved human forearm bone engraved with zig-zag markings and broken open to extract the marrow. Photo: the Natural History Museum of London and University College London

Prehistoric cannibals did not eat other humans just to survive – there was also meaningful ritual behind the grisly funerary feasts, according to new research.

The bones found in the United Kingdom date from about 14,700 years ago. A particular human radius shows the meat was filleted off and zigzag patterns were gouged into the side before the bones were broken open for the marrow inside, reports a team of archaeologists in the journal PLoS One.

“The sequence of the manipulations suggests that the engraving was a purposeful component of the cannibalistic practice, implying a complex ritualistic funerary behavior that has never before been recognized for the Paleolithic period,” write the authors, from the Natural History Museum of London and University College London.

The same team has previously studied other remains found at Gough’s Cave in Somerset, of the Magdalenian period of European history. They have previously studied skulls cut to make cups, and other bones showing human tooth marks.

The latest study shows over 300 filleting marks on human and animal remains at the site. A series of 119 purposefully engraved incisions were made on two of the bones, they found.

The remains did not show ante-mortem violence, however. These post-mortem operations were carefully completed, said Silvia Bello, of the Natural History Museum, the lead author.

“The way the bone was modified suggested that the filleting of human bodies during cannibalism and the engraving of this human bone were intricately related, as part of a ritual,” she said, in a statement from the museum.

The engravings were made by a single hand, using one tool, after the bones were cleaned and before they were broken open, they found. They were made with 87 cuts: 33 single strokes, and 32 to-and-fro sawing motions, they found.

“The marks must have held a symbolic connotation,” added Bello.

A similar zig-zag pattern was found on tools made of animal bones in France. But these bones found in England were earlier – and human.