Geschichte: We found our 'Reisestein' during a vacation in Liguria in April 2022. My youngest son loves to pick up stones in the beach and crack them apart by smashing the rocks onto other stones. One rock revealed to contain a hidden fossil. A true gem my son is very fond of.
Geologie: The fossil is an irregular sea urchin. Irregular sea urchins, in contrast to regular sea urchins, move along by digging in the sediment. This way of life lead to the replacement of the five-rayed symmetry (otherwise typical for echinoderms such as crinoids, sea urchins, sea cucumbers, etc.) by a bilateral symmetry. The mouth and anus of these sea urchins are usually on the underside (the picture shows the upper side).