Wikipedia
Diplocidaris
Diplocidaris is an extinct genus of sea urchins belonging to the family Diplocidaridae. The type species of this genus is Cidaris gigantea Agassiz, 1840.
These slow-moving low-level epifaunal grazer-omnivores lived in the Jurassic period, from 161.2 to 150.8 Ma. Fossils of this genus have been found in the sediments of Europe, North Africa, Madagascar.