Image Credit: pol.dk
English scientists were surprised by what they found inside a 2,500- year-old human skull back in 2008: the person’s brain was still there. The discovery of the brain – with a yellowish appearance, more wrinkled and shrunken than normal – raised questions about how such a fragile body could have survived so long and how often this strange kind of preservation occurs. It is common to find skull dating from long ago, but they are always empty.
Except the brain, all the soft tissues of the skull were gone when the skull was taken from a muddy pit of the Iron Age, where the University of York, England, planned to build new buildings of its campus.
“It was just amazing to think that the brain of someone who had died so many thousands of years ago could only persist for being in a humid environment” , is surprised Sonia O’Connor, a postdoctoral researcher at the University of Bradford, England. O’Connor led a team of scholars who assessed the state of the brain after it was found in 2008, and analyzed the possible conservation modes.
“It is particularly surprising because, if you talk to pathologists who deal with fresh corpses, they say the first organ to deteriorate and basically turn liquid is just the brain, because of its high fat content,” explains O’Connor.
When found, the skull – which belonged to a man, probably between 26 and 45 years old – was accompanied by a jaw and two vertebrae of the neck, revealing evidence of hanging followed by decapitation. Cut marks on the inside of the neck indicate that the head was cut off while there was still flesh on the bones, according to O’Connor. There is, however, no indication of why he was hanged or why his remains had not been found until 2008.
More than a decade earlier than that, O’Connor was involved in the discovery of 25 heads preserved in the medieval era in the area of Kingston-upon-Hull, England. In the brains they were found only bones. All other soft tissue had disappeared.
In this sense, the brain – called Heslington – and medieval remains are quite different from mummies, intentionally frozen or preserved bodies, because in such cases other soft tissues – such as skin, muscles and so on – are also preserved. None of the newly found item showed any signs that were intentionally preserved.
The Heslington body along with other O’Connor discoveries appear to have been buried in moist environments quickly after death, where the absence of oxygen prevented the decay of brain tissue. “But even if the oxygen-free environment seems to be the key element, you cannot rule out other factors like certain diseases or physiological changes – such as those that accompany hunger – that may predispose the brain to be preserved that way,” says O’Connor.
After being deposited in the humid environment of the well, the Heslington brain began to change chemically, making it a durable material. It was reduced to a quarter of its size. The chemical details of the new material are still under investigation.
In an unpublished study, O’Connor’s team has put together a list of other similarly preserved brains found since 1960. Reports like these usually do not get much attention even among the archaeological society. So much so that when archaeologists discover a preserved brain, they tend to think that is the first of this kind of findings, according to O’Connor.
“Part of the problem is that archaeologists are very happy to deal with the remains of human skeletons, but as soon as there is any soft tissue signal, the situation becomes psychologically very, very different. You are no longer dealing with a skeleton, you are dealing with the remains of a corpse and of course, a corpse is a dead person,” says O’Connor.
The skull was dated sometime between 673 and 482 BC. The Romans, however, only reached the area in the year 71 AD, according to Richard Hall, archeology director of the university hired to evaluate the site and take care of the excavation in Heslington. The area appears to have been a permanent settlement with ditches dividing it into fields and pathways through which livestock can be conducted, according to Hall.
Archaeologists also found evidences in the site that they believe have been houses with thatched roofs, as well as the site probably used for water storage.
No one knows for sure what the skull with the preserved brain was doing in the well of the region. No other human remains found at the site.