The Echinoid Directory

Contributed by Andrew Smith, August 2011

Pachyclypus Desor, 1857, p. 195

[=Pachyclypeus Cotteau, 1873, p. 389, nomen vanum ]

Diagnostic Features	Test large, ovoid, rounded at front and domed Apical disc compact with four genital plates, five small ocular plates and a single complemental plate separating the two posterior genital plates. Ambulaca simple, non-petaloid adapically; without pore-crowding towards the peristome (Cotteau\'s figure is wrong in this regard). Peristome small, depressed, without obvious buccal notches
Distribution	Upper Jurassic (Oxfordian), France
Type	Dysaster semiglobosus Desor, 1842, p. 195 [=Nucleolites semiglobus Munster, in Goldfuss, 1829, p. 139] by monotypy.
Species Included	Only the type species
Classification and/or Status	Stem group Microstomata; Desorellidae Monotypic
Remarks	Included in the family Infraclypeidae by Saucede et al., (2007), who provide a good illustration of the apical disc. Close to Desorella in form but with a more compact apical disc. Desor, E. 1855-1858. Synopsis des echinides fossiles. Reinwald, Paris, 490 pp. Saucede, T., Mooi, R. & David, B. 2007. Phylogeny and origin of Jurassic irregular echinoids (Echinodermata: Echinoidea). Geological Magazine 144, 333-359.