The Echinoid Directory

Contributed by Andrew Smith, April 2011

Desoricidaris Geys, 1992, p. 140

[includes species that have wrongly been assigned to Leiocidaris Desor, 1855 previously]

Diagnostic Features	Apical disc opening large; plating unknown. Ambulacral zones straight, ambulacral plating simple throughout. Ambulacral pore-pairs strongly conjugate, linked by a well-marked groove. Ambulacral tuberculation consisting of well developed marginal tubercles and perradial band of smaller tubercles and granules. Interambulacra composed of relatively small number of plates; primary tubercles large and non-confluent at ambitus; areoles deeply impressed. Scrobicular tubercles clearly differentiated; extrascrobicular zones wide and covered in dense uniform granules. Sutures depressed but no sutural pits. Adapical plate in each column with only a rudimentary tubercle. Tubercles perforate and non-crenulate. Peristome smaller than apical disc opening; plating unknown. Spines and lantern unknown.
Distribution	Cretaceous of southern Europe, North Africa and the Middle East.
Name gender	feminine
Type	Rhabdocidaris pouyannei Cotteau, 1863, p. 346, by original designation.
Species Included	Geys (1992) included the following taxa when establishing this genus: D. pouyannei (Cotteau, 1863); Cenomanian-Turonian, Algeria, Egypt D. sanctaecrucis (Cotteau, 1862); Valanginian, Switzerland D. salvensis (Cotteau, 1857); Lower Cretaceous, Europe D. venulosa (Agassiz & Desor, 1846); Cretaceous, Europe D. balli (Fourtau, 1914); Cenomanian, Egypt D. bonolai (Gauthier, in Fourtau, 1900); Cenomanian, Egypt D. subvenulosa (Cotteau et al. 1880); Turonian, Algeria D. crameri (de Loriol, 1887); Santonian, Egypt D. schweinfurthi (Gauthier, in Fourtau, 1901); Santonian, Egypt.
Classification and/or Status	Cidaroida; Cidaridae; Stereocidarinae
Remarks	This genus was established for cidarids with non-crenulate tubercles and strongly conjugate pore-pairs. These have often been assigned to the genus Leiocidaris by older authors but Leiocidaris is a synonym of Phyllacanthus. The type species, with its well-developed extrascrobicular zones, sunken sutures and adapical interambulacral plates that lack fully developed tubercles has close affinities with the Stereocidarinae and is here treated as a genus of that subfamily. Geys,J. F. 1992. Regular echinoids, other than Hemicidaroida, from Upper Cretaceous deposits in the Wadi Qena-area (Eastern Desert, Egypt). Bulletin de l'Institut Royal des Sciences naturelles de Belgique. Sciences de la Terre 62, 139-154.