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The Echinoid Directory

Typocidaris Pomel, 1883, p. 111

Diagnostic Features
  • Test relatively thick.
  • Apical disc about 50% test diameter; plating unknown.
  • Interambulacra with relatively few plates (5) in a series. One adapical plate in each zone vertically elongate and lacking a fully formed primary tubercle. Sutures weakly incised.
  • Primary tubercle perforate and non-crenulate (adapical tubercles may show traces of crenulation around their adapical side). Areoles circular and incised; widely separated on ambital and adapical plates.
  • Scrobicular tubercles differentiated. Wide extrascrobicular zones densely and uniformly covered in secondary tubercles, with neural grooves.
  • Ambulacra sinuous; pore zones slightly incised; pore-pairs subconjugate with the two pores separated by a low node slightly wider than a pore. Tuberculate zone wide, slightly sunken centrally. Each plate with a row of subequal tubercles these also forming vertical series.
  • Primary spines, none definitely associated with test.
Distribution
The type species comes from the Aptian of France and the UK.
Name gender feminine
Type
Cidaris malum Gras, 1848, p. 22, by monotypy.
Species Included
  • Only the type species.
Classification and/or Status

Cidaroida; Cidaridae, Stereocidarinae.

Provisionally treated as a subjective junior synonym of Temnocidaris (Stereocidaris).
Remarks

The species is discussed in Smith & Wright (1989) and Vadet (1988). Close to Temnocidaris but differing in the absence of pits in extrascrobicular interambulacral zones. Cidaris heteracantha Gras, 1848, based on isolated spines and coming from the same beds as tests of T. malum probably represent the spines of this species.

Pomel, A. 1883. Classification méthodique et Genera des Échinides vivante et fossiles. Thèses présentées a la Faculté des Sciences de Paris  503, A. Jourdan, Alger, 131 pp.

Vadet, A. 1988. Revision des "Cidaris" de l'Oxfordien et du Kimmeridgien Europeens. Memoires de la Societe academique du Boulonnais 4, 1-148, pls 1-25.

Smith, A. B. & Wright, C. W. 1989. British Cretaceous echinoids. Part 1, General introduction and Cidaroida. Monograph of the Palaeontographical Society [publication no. 578, issued as part of volume 141].