The Echinoid Directory

Entomaster Gauthier, 1888, p. 532

Diagnostic Features
  • Test large and cordate with deep anterior sulcus; subconical in profile. Widest point anterior of centre. Lower surface flat; subconical in profile with truncate posterior.
  • Apical disc somewhat anterior of centre; four gonopores (no supplementary gonopores on ocular plates).
  • Frontal groove continues to apex, but shallows adapically; deep and sharply defined sulcus on oral surface leading to peristome.
  • Paired ambulacra sub-petaloid; pore-pairs weakly circumflexed.
  • Peristome small and circular; vertical and facing anterior. Opening close to the anterior border.
  • Plastron plating orthosternous - labral plate followed by single symmetrical sternal plate. Episternal plates opposite and equal; subsequent plating also opposite.
  • Periproct transverse and very low down on posterior face. Posterior face truncate and slightly depressed.
  • Enlarged primary tubercles scattered over all interambulacral zones aborally.
  • No fascioles (preservation poor).
Upper Cretaceous (Upper Campanian), Tunisia.
Name gender masculine
Entomaster rousseli Gauthier, 1888, p. 532, by original designation. Figured syntype: Museum National d\'Histoire Naturelle, Paris, J01446.
Species Included
  • Only the type species.
Classification and/or Status

Holasteroida, Meridosternata, Stegasterina, Stegasteridae.



Differs from Guettaria in having the peristome closer to the anterior border, and in having more major tubercles aborally and more equal ambulacral zones aborally. Differs from Stegaster in having symmetric episternals and post-episternals. Differs from Seunaster and Lampadaster in having coarse aboral tuberculation.

Gauthier, M.V. 1888. Types nouveaux d\'echinides Cretaces. Compte Rendu de l'Association francais pour l'advancement des Sciences. 16e session, Toulouse, 1887. 2, Notes et Memoires 527-534.

Zaghbib-Turki, D. 1987. Les echinides du Cretace de Tunisie. Unpublished Ph. D. Thesis, Faculte des Sciences, Universite de Tunis.