British archaeologists have unveiled an ancient skull with a brain inside they consider to be the oldest surviving human brain in Britain, dating back at least 2,000 years to the Iron Age. The team, excavating a York University site, discovered a skull containing a yellow substance which scans showed to be shrunken, but still brain-shaped.

The brain was discovered in an area of extensive prehistoric farming landscape of fields, track ways and buildings dating back to at least 300BC. The gray matter had to put up with quite a lot during the time underground, so it's not quite clear how much of it is really left. An awkward thing about it though, is that the “brain-full” skull was buried separately from the body. This would seem to suggest that ritual burial or human sacrifice were being practiced.

Archaeologist Rachel Cubitt, from the York Archaeological Trust, noticed the brain as she cleaned the soil-covered bone. Ms Cubitt said she looked through the base of the skull after feeling something move inside and saw an unusual yellow substance. "It jogged my memory of a university lecture on the rare survival of ancient brain tissue," she said. A sophisticated CT scanner at York Hospital was then used to produce startlingly clear images of the skull's contents.

Researchers named it the oldest brain ever found in Britain, although it is miles away from the record for the oldest brain ever discovered: That honor belongs to the roughly 8,000-year-old scraps of brain tissue that were found in skeletons buried in a Florida peat bog. In the Florida case, the absence of bacteria in the acidic peat bogs allowed the organic tissue to be preserved; researchers still aren’t sure how the York brain was preserved or whether the yellow substance has any organic matter in it.

The existence of a brain where no other soft tissues have survived is extremely rare, according to Sonia O'Connor, an archaeological researcher at the University of Bradford in northern England who helped authenticate the discovery.

"It's a real freak of preservation to have a brain and nothing else," Chris Gosden, a professor of archaeology at Oxford University unconnected with the find told the Associated Press. "The fact that there's any brain there at all is quite amazing."

Scientists now hope further tests may tell them more about the individual the brain belonged to by revealing why such brains survive death and burial and giving more information about burial practices. The great thing is that brains are usually one of the first body parts to begin decomposing after death, and researchers pronounced themselves amazed that any part of the Iron Age individual’s gray matter was preserved.

This finding is the second major discovery during investigations at this very site. Previously this year, a team from the university's department of archaeology unearthed a shallow grave containing the skeleton of a man believed to be one of Britain's earliest victims of tuberculosis.