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.