Photo of Micraster fossil



While living these urchins are covered with a layer of little spines which disguise the shape of is test. Stripped of this layer in death, the shape of the shell is a chunky heart shape, adorned with the typical five-pointed star shape of sea urchins.

These Micraster gibbus are found as tough little nodules in a 80 million year-old chalky limestone near Hanover, Germany.