New analysis of an almost complete skull of a cow from a Neolithic site in France suggests it may have undergone cranial surgery about 5400 years ago, which could provide the earliest evidence of surgical experimentation on an animal.
Scientists Fernando Ramirez Rozzi, from the French National Centre for Scientific Research, and Alain Froment, from France’s Institute of Research for Development, analysed the cow cranium found at the site of Champ-Durand, about 40 kilometres from the Atlantic coast.
Champ-Durand was a fortified locality described as an important Neolithic trade centre for local populations specialising in salt production and cattle slaughter.
Rozzi, lead author of a paper published in the journal Scientific Reports, says if the cranial surgery observed on the cow was performed to save the animal, it provides the earliest evidence of veterinary surgical practice. And if the operation was used to practice techniques, “the cow from Champ-Durand would provide the earliest evidence of surgical experimentation on an animal, indicating that this practice already existed in 4000 BC”.
The cow cranium, which lacked only the anterior part of the maxilla and the extremities of the horns, had a hole in the right frontal lobe bone. Previous examinations had concluded the hole had been the result of goring by another cow, but this latest research revealed features that seem to indicate it may be related to human activity.
There were no fractures or splintering to suggest a goring, and the almost square shape, the lack of marks indicating pressure by an exterior force, and the presence of cut-marks around the edges, suggest that the hole may have been the result of a surgical process known as trepanation, or trepanning.
There is evidence that humans have practiced trepanation as early as the Mesolithic period, some 11,600 years ago. Thousands of skulls bearing signs of the procedure have been unearthed at archaeological sites across the world. But despite its apparent importance, scientists are still not completely agreed on why our ancestors performed trepanation.
Likewise, how such surgical mastery was acquired in prehistoric societies remains an open question.
Rozzi says his group’s examination of this cow skull reveals that it underwent cranial surgery using the same techniques as those used on humans.
Alternatively, he says, the evidence of surgery could also suggest that Neolithic people practiced on domestic animals in order to perfect the technique before applying it to humans.
The report notes that evidence of cranial surgery in human history is well represented throughout the world, and its use has been documented in skeletal remains from every continent, most of them from the Mesolithic to the present time.
“The purpose of such a practice, we suppose, most probably depends on the societies and/or the period in question,” the researchers write.
However, they continue, “one cannot but be amazed by prehistoric man’s knowledge and mastery of the techniques of cranial surgery. Indeed, the oldest crania with evidence of trepanation reveal the use of the same techniques as those used in historic times with the same degree of accuracy. Similar techniques are recorded all over the world.”
The report suggests people may have practiced on the skulls of the dead. But techniques developed on the crania of cadavers could lead to brain damage when practiced on living patients, “and it would be difficult to recognise dangerous gestures on anyone but live patients”.
“It is also possible that they trained on live animals … Unfortunately, complete skulls of animals are rarely found in archeological sites since they were eaten and the skulls were most probably broken to extract the tongue and the brain.”
The researchers used 3-D reconstruction from x-ray scan projections and scanning electron microscope analyses to examine the skull, and radiological studies confirmed the lack of healing processes in the bone tissue around the hole.
“Therefore the animal did not survive the injury, or was killed shortly afterwards, or the trauma occurred once the animal was already dead,” Rozzi says.