Scientists may have partially cracked how Britain's oldest known human brain was "pickled" in mud for some 2,500 years.
First dug up by archaeologists in York, England (see map), in 2008, the well-preserved chunk of ancient gray matter prompted experts to investigate how the brain had stayed in such good shape. (See more pictures of the brain.)
Results of a new study found no chemical signs of deliberate preservation, either by embalming or smoking.
Instead, the team suggests that the brain was quickly buried in a pit full of thick, wet clay—among several factors that may have helped prevent the organ from decomposing.
(See "Oldest Fossil Brain Found in 'Bizarre' Prehistoric Fish.")
Protein analysis also confirms the ancient brain—dated to between 673 and 482 B.C.—belonged to a human, said study co-author Matthew Collins, an archaeologist at the University of York.
"The majority of the mass of the brain is still there, but it's quite reduced in volume—it's lost a lot of water."
Iron Age Man Hanged, Then Decapitated
Analyses of the brain and remains of the surrounding skull suggest the Iron Age brain belonged to a male between 26 and 45 who was hanged and then ritually decapitated. The rest of the man's body hasn't been located.
Gruesome neck-vertebra fractures and cut marks show the man was hanged and his head was sliced off after death with a knife or other sharp instrument, scientists say.
The presumably fatal neck injury "is sometimes referred to as a hangman's fracture, and it is consistent with a long-drop hanging," said study co-author Jo Buckberry, an archaeologist at the University of Bradford.
"On the same vertebra there are a series of nine small incisions made by a bladed instrument, which are consistent with a careful decapitation," Buckberry said.
(See "51 Headless Vikings in English Execution Pit Confirmed.")
"My feeling is the individual would have died from the fracture and the head was removed and deposited in the pit."
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