LONDON , England ( CNN ) -- Archaeologists have discovered what they say is the oldest surviving human brain in Britain , dating back at least 2,000 years to the Iron Age . A representation of the skull generated from the CT scans taken at York Hospital . The remains of the brain were found in a skull unearthed during excavations at York University in northern England , a statement from the university said Friday . The dig site was described by investigators from York Archaeological Trust as being in an extensive prehistoric farming landscape of fields , track ways and buildings dating back to at least 300 BC . They believe the skull , which was found on its own in a muddy pit , may have been a ritual offering . Rachel Cubitt , who was taking part in the dig , described how she felt something move inside the cranium as she cleaned the soil-covered skull 's outer surface . Peering through the base of the skull , she spotted an unusual yellow substance . `` It jogged my memory of a university lecture on the rare survival of ancient brain tissue . We gave the skull special conservation treatment as a result , and sought expert medical opinion , '' she said in a statement on York University 's Web site . A sophisticated CT scanner at York Hospital was then used to produce startlingly clear images of the skull 's contents . Philip Duffey , Consultant Neurologist at the Hospital said : `` I 'm amazed and excited that scanning has shown structures which appear to be unequivocally of brain origin . I think that it will be very important to establish how these structures have survived , whether there are traces of biological material within them and , if not , what is their composition . '' Dr Sonia O'Connor , Research Fellow in Archaeological Sciences at the University of Bradford added : `` The survival of brain remains where no other soft tissues are preserved is extremely rare . This brain is particularly exciting because it is very well preserved , even though it is the oldest recorded find of this type in the UK , and one of the earliest worldwide . '' According to York University , the find is the second major discovery during archaeological investigations on the site of the University 's $ 745 million campus expansion . Earlier this year , the skeleton of a man believed to be one of Britain 's earliest victims of tuberculosis was discovered in a shallow grave . Radiocarbon dating suggests that the man died in the fourth century late-Roman period .
Skull found at site of York University 's $ 745 million campus expansion . Investigator spotted an unusual yellow substance inside the skull . Hospital scanner used to produce clear images of the brain tissue . Expert : Survival of brain remains where no other soft tissues are preserved is rare .