The Echinoid Directory

Eoholaster Solovjev, 1989, p. 150

Diagnostic Features
  • Test ovate with convex anterior. Shallow sulcus on oral surface.
  • Apical disc with four gonopores. Posterior oculars stretched and only one directly in contact with posterior genital plates in the type species.
  • All ambulacra similar; pore-pairs minute and simple; the two columns equally developed.
  • Plastron plating protosternous with labral plate in broad contact with both succeeding sternal plates.
  • Periproct marginal, on near-vertical posterior face.
  • Tuberculation apparently rather fine.
  • No fascioles.
Lower Cretaceous (Berriasian); Ukraine and North Africa.
Name gender masculine
Eoholaster poslavskae Solovjev, 1989, p. 150, by original designation.
Species Included
  • E. poslavskae Solovjev, 1989; Berriasian of Ukraine.
  • E. laffittei (Devries, 1960), Berriasian of Algeria.
Classification and/or Status

Holasteroida, basal stem group.

Presumed paraphyletic as currently construed by exclusion of allother Cretaceous to Recent taxa.


The type species differs from all non-urechinid holasterids in having the posterior ocular plates only in tenuous connection with the posterior paired genital plates. The left posterior ocular plate touches the right posterior genital plate but not the left posterior genital plate and the right posterior ocular plate is distal to the left posterior ocular plate and removed from its genital plate (see figure above). Proholaster Gauthier, 1896, from the early Cretaceous of Tunisia is very similar, but has the posterior oculars completely separated from the posterior genital plates and has a distinct anterior sulcus.

Solovjev, A. 1989. New echinoid genus Eoholaster (Spatangoida, Holasteridae) from the Berriasian. In: Fossil and recent echinoderm researches. Academy of Sciences of the Estonian SSR, Institute of Geology and Academy of Sciences of the USSR. Tallinn. Pp. 148-155.