''Hemicidaridae'' is a family of extinct

sea urchin Sea urchins () are spiny, globular echinoderms in the class Echinoidea. About 950 species of sea urchin live on the seabed of every ocean and inhabit every depth zone from the intertidal seashore down to . The spherical, hard shells (tests) of ...

s characterized by large, massive, club-shaped spines. These epifaunal grazer-deposit feeders lived in Jurassic and Cretaceous ages (from 189.6 to 112.6 Ma).

Taxonomy

List of genera and subfamilies: * Subfamily Hemicidarinae Wright, 1857 † :''

Asterocidaris ''Asterocidaris'' is a genus of fossils sea urchins in the family Hemicidaridae. These epifaunal grazer-deposit feeders lived in the Middle and Upper Jurassic age (from 171.6 to 161.2 Ma). Species * ''Asterocidaris besairiei'' Lambert, 1936 � ...

'' Cotteau, 1859 † :'' Gymnocidaris'' L. Agassiz, 1838 † : '' Hemicidaris'' L. Agassiz, 1838 † * Subfamily Pseudocidarinae Smith & Wright, 1993 † :'' Cidaropsis'' Cotteau, 1863 † :'' Pseudocidaris'' Pomel, 1883 † :'' Gymnocidaris'' L. Agassiz, 1838 † : '' Hemicidaris (Sphaerotiaris)'' Lambert & Thiéry, 1914 †

Distribution

Fossils of species within this genus have been found in the Jurassic and Cretaceous sediments in Europe, Africa, North America and China.

References

Prehistoric echinoderm families Jurassic first appearances Cretaceous extinctions {{paleo-echinoidea-stub