HemicidaridaeHemicidaridae is a family of extinct sea urchins characterized by large, massive, club-shaped spines.These epifaunal grazer-deposit feeders lived in Jurassic and Cretaceous ages.TaxonomyList of genera and subfamilies: Subfamily Hemicidarinae Wright, 1857 † Subfamily Pseudocidarinae Smith & Wright, 1993 †DistributionFossils of species within this genus have been found in the Jurassic and Cretaceous sediments in Europe, Africa, North America and China.