The Echinoid Directory

Family Hemipneustidae Lambert, 1917, p. 2

Diagnosis

Holasteroids with:

plastron protosternous to metasternous with wedge-shaped plates extending most of the plastron width
apical disc with hydropores scattered over anterior genital and ocular plates
peristome with projecting labrum
periproct marginal to inframarginal with double subanal bulge
ambulacra mostly with strongly differentiated anterior and posterior columns of pore-pairs (pore-pairs in posterior column much better developed)
petals strongly flexed.

Range

Late Cretaceous (Campanian) to Miocene; Europe, North Africa, Europe, Middle East, India.