Cidaroida is an order of primitive sea urchins, the only living order of the subclass Perischoechinoidea. All other orders of this subclass, which were even more primitive than the living forms, became extinct during the Mesozoic.

Cidaroida. Retrieved November, 05 2021, from en.wikipedia.org/wiki/Cidaroida.

Cidaridae is a family of sea urchins in the order Cidaroida.

Cidaridae. Retrieved November, 05 2021, from en.wikipedia.org/wiki/Cidaridae.