The object in hand for this week’s coronation-themed Keepers Corner is sometimes called a ‘shepherd’s crown’
The ‘shepherd’ part comes from the fact that such objects are often found in farmers’ fields. The ‘crown’ part is based on its shape and the five pairs of dotted lines running up the side like the arches of a crown. In reality, it is a fossil sea urchin dating back 93 to 66 million years ago. This was a time of major global warming with most of Britain covered by an expansive sea in which thick layers of chalk were being laid down. Many different types of sea urchin lived and died on the prehistoric seafloor before becoming buried and fossilised. Millions of years later, sea levels fell and the land rose up to form the chalky hills and fields we see today in the Chilterns. Here, thanks to weathering and the farmer’s plough, fossils are slowly being revealed for shepherds and walkers alike to discover. You can find a selection of local fossil sea urchins on display in the Museum’s Discover Bucks Geology gallery.