It was found in 2015 – an isolated clue to a macabre mystery that has been going on for thousands of years in the past.
This ancient puzzle consists of only one piece: a lone human skull, discovered on its own without any other skeletal remains in the vicinity of a cave in Bologna, Italy, in the middle of a cave-like depression call the locals Dolina dell’Inferno (Hell’s sinkhole).
It was not an easy thing to find.
The well-concealed skull, which lacks its lower jaw, could only be reached by a difficult cave passage which the Meandro della cattiveria (Maze of Malice), and then with a vertical scale up to a height of 12 meters (39 feet), where the skull rests on a rocky ridge.
Due to the difficulty of gaining access to the site, speleologists were only able to pick up the skull in 2017, when researchers had the chance to study this mysterious, ancient specimen.
The solitary skull does indeed appear to be old, with radiocarbon dates suggesting that the skull belonged to an individual who lived somewhere between 3630 and 3380 BC, and this within the archaeological context of the early Aeolithic (also known as Chalcolithic) period of the region.
Other eneolithic remains were found in the general area; not in hell’s sinkhole, but in a rock shelter about 600 feet from the cave in which the skull was found.
The larger context therefore makes sense. But how exactly did this lone skull come so far away from its peers, placed high on a ledge, yet buried in a malicious maze in a cave and hidden under the ground at a depth of 26 meters (85 feet)? ?
According to anthropologist Maria Giovanna Belcastro of the University of Bologna – the first author of a new analysis of the unusual fate of the skull – there were a number of factors at stake.
Belcastro’s team has examined the skull, which according to the team is probably from a young woman, between 24 and 35 years old.
Evidence of various lesions on the sides of the skull is probably the result of human manipulations of the skull at the time of the woman’s death, the researchers suggest that it may be a reflection of ritual acts to remove meat from the skull as part of a funeral service.
Other lesions on the skull, some of which may have been a corpse (before death), may be the result of an injury that killed the woman, and other signs may be evidence of a kind of medical treatment that her men liver.
Regarding the manner in which the skull was thus separated from the rest of its skeleton, the researchers suspect that the skull could have been intentionally or accidentally removed from the rest of the body, before it was pushed over the ground by water or mud flow, until it somehow got to the edge of hell’s sinkhole and eventually fell into depression.
Over time, water infiltration into the sinkhole could dissolve gypsum deposits in the cave, creating the vertical axis along the safe resting place of the skull.
“The reactivated cave passage began to develop downwards, with the formation of a lateral sinking creek and the maze lying beneath it carved out,” the researchers write in their paper.
“This new reactivation was able to hedge about 12 meters of plaster and connect it to the lowered base level.”
Several sediments in the skull cavity provide some support for this argument, suggesting that matter got stuck in the skull during water or litter flow, as the skull undertook its improbable, chaotic journey into the cave. Signs of other trauma to the skull indicate many bumps during the ride.
This hypothetical interpretation, of course, is not what necessarily happened, it is something we can never really know. But as the researchers note, of all the parts of a human skeleton, the shape of a skull is the most suitable to make a runaway.
“If the skeleton had been intact by the time of this event, other skeletal elements, which had different shapes and sizes, would have been trapped and scattered elsewhere during transportation,” the authors suggest.
“The skull would have rolled more easily than other skeletal parts flowing in a stream of water and debris … During its decomposition and the dynamic phases it would have been filled with sediment. Therefore, it would have reached the cave and stopped on the plateau where it has been found. ‘
The findings are presented in PLOS Een.