Several species of sea urchin are commonly called Diadema urchins, go here for a discussion colspan=2 style="text-align: center; background-color: transparent; text-align:center; border: 1px solid red;" | Diadema urchin 250px colspan=2 style="text-align: center; background-color: transparent; text-align:center; border: 1px solid red;" | Scientific classification Kingdom: Animalia Phylum: Echinodermata Class: Echinoidea Subclass: Euechinoidea Superorder: Diadematacea Order: Diadematoida Family: Diadematidae Genus: Echinothrix Species: E.