The Echinoid Directory

Glyptodiadema Pomel, 1883, p. 102

[=Eodiadema Duncan, in Wilson & Crick 1889, p. 339, type species Eodiadema granulatum Wilson, in Wilson & Crick, 1889. ]

Diagnostic Features	Test small, with domed upper surface. Apical disc only partially preserved; appears to be hemicyclic. Ambulacra straight, with trigeminate plating throughout. Plate compounding acrosaleniid style, with primary tubercle overlapping two elements in each triad. All three elements identical in shape. Interambulacra with single primary tubercle that is perforate and crenulate.
Distribution	Lower Jurassic (Pliensbachian), France and England
Name gender	neuter
Type	Pseudodiadema cayluxensis Cotteau, 1878, p. by monotypy. Holotype: University of Lyon Palaeontological Collections EM 40237.
Species Included	G. cayluxensis (Cotteau, 1878); Upper Pliensbachian, France G. granulatum (Wilson, in Wilson & Crick, 1889); Pliensbachian, England
Classification and/or Status	Euechinoidea, Echinacea or Diadematoida?
Remarks	The smooth outline of the periproct and the absence of any periproctal plates intercalated into the disc suggests this is a diadematoid or an early Echinacea rather than a Calycina. Knowledge of its lantern structure is, however, needed to place this taxon with certainty. Cotteau, G. 1878. Echinides Nouveau ou peu connus. Revue et Magazin de Zoologie 29, 140-145. Cotteau, G. 1882. Paleontologie Francaise. Terrains Jurassiques. X, Echinides reguliers. G. Masson, Paris. 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, 131 pp. Aldolphe Jourdan, Alger.