Rachel Cubitt, one of the researchers on the dig, felt something moving inside the skull and noticed “an unusual yellow substance” when she peered through an opening in its base.
Later on, a computed tomography (CT) scan performed by neurologists at York Hospital revealed that the skull contained a shrunken brain-shaped structure. Further analyses will now be carried out to establish whether the yellow substance is indeed brain tissue.
The brain consists of soft tissue and so does not normally fossilize. This finding is therefore extremely unusual, and the researchers will be very keen to understand how it came to be preserved for such a long period of time.