My 8 year old daughter found this fossil when playing in our local football field in the Watford area, hertfordshire. It resembles a small starfish. I wondered if anyone had any ideas what this fossil is and how old it might be? Thanks, Jennifer
Yes - it is a sea urchin, of sorts - perhaps more correctly called a 'sand dollar' in this case. The five-fold symmetry is the key, pointing the finger at Echinodermata, though one has to allow a bit of flexibility in that five divisions are not necessary equal in some species. We don't really have enough information to tell you which species your fossil belongs to.