The Echinoid Directory

Echinotiara Pomel, 1883, p. 83

[=Echinodiadema Cotteau, 1869, (non Verrill, 1867);  =Leioechinus Kier, 1972, p. 48, type species Leioechinus namus Kier, 1972]

Diagnostic Features
  • Test rounded to subpentagonal in outline, depressed above and below with rounded ambitus.
  • Apical disc small, firmly bound to coronal, dicyclic, with anterior genital plates larger than posterior pair. Periproct relatively large and with smooth, rounded margins.
  • Ambulacral zones much narrower than interambulacral zones; plating trigeminate with plate compounding diadematid style (all three elements reach the perradius (at least aborally). Each compound plate with a primary tubercle, adjacent to the pore zone leaving a broad perradial granular zone.
  • Pore-pairs in offset arcs of 3, expanded adorally to form phyllodes.
  • Interambulacral plates wide, each with a central primary tubercle. At the ambitus and adorally there is a smaller adradial flanking scondary tubercle. The remainder of the plate is covered in dense granulation.
  • Distinct interradial naked zone developed adapically.
  • Peristome moderate, hardly sunken; buccal notches open, giving the peristome edge a scalloped appearance.
  • Spines and lantern unknown.
Distribution
Jurassic (Toarcian) to Upper Cretaceous (Maastrichtian), Europe, North Africa, Middle East.
Name gender feminine
Type
Echinodiadema bruni Cotteau, 1869, p. 671 by monotypy.
Species Included
  • E. amplus Kier, 1972; Callovian, Saudi Arabia.
  • E. arabica Melville, 1955; Toarcian, Saudi Arabia.
  • E. bruni (Cotteau, 1869); Bathonian, France.
  • E. namus Kier, 1972; Bathonian, Saudi Arabia.
  • E. perebaskinei Lambert, 1930; Campanian-Maastrichtian, Sudan, Saudi Arabia.
  • E. somaliensis Currie, 1927; Bathonian-Callovian, Somalia

Classification and/or Status
Euechinoidea, Echinacea, Stomechinidae.
Remarks

Almost identical to Stomechinus in tuberculation pattern and appearance, differing in having pore-pairs forming a single irregular line above the ambitus rather than a broad adradial zone of offset triads.

Cotteau, G. 1869. Echinides nouveaux ou peu connus. Revue et Magazin de Zoologie 21, 238-248.

Melville, R. V. 1955. Echinotiara arabica sp. nov., a regular echinoid from the Toarcian of central Arabia. Geological Magazine 92, 393-401.

Pomel, A. 1883. Classification méthodique et Genera des Échinides vivante et fossiles. Thèses présentées a la Faculté des Sciences de Paris pour obtenir le Grade de Docteur ès Sciences Naturelles 503, Aldolphe Jourdan, Alger, 131 pp.

Smith, A. B., 1995. Upper Campanian-Maastrichtian echinoids from the United Arab Emirates - Oman border region. Bulletin of the Natural History Museum, London (Geology) 51, 121-240.