Iron Age Brain ScanA computer-generated scan of a 2,500-year-old human skull shows brain matter in dark gray. The lighter gray colors in the skull represent soil.
First dug up in 2008 by archaeologists in York, England (see map), the well-preserved brain prompted experts to investigate how the tissue had stayed in such good shape.A new study released in March suggests that the skull had been quickly buried in a pit full of thick, wet clay—among several factors that may have helped prevent the brain from decomposing.The cool, low-oxygen conditions of the soil may have aided in the brain's preservation, according to the study, published in March in the Journal of Archaeological Science.—With reporting by James Owen

Photograph courtesy York Archaeological Trust