Contributed by Andrew Smith, August 2008
|Distribution||Jurassic (Bathonian-Oxfordian), Europe|
|Type||Clypeus orbicularis Phillips, 1829, p. 144, 189, pl. 7, fig. 3.
Lectotype of Clypeus orbicularis Phillips, 1829: Oxford University Museum J7366
|Species Included||Only the type species included for certain.|
|Classification and/or Status||Irregularia; Cassiduloida; stem group
|Remarks||Distinguished from Nucleolites and its relatives by having a primitive apical disc structure with catenal plates separating left and right genital and ocular plates behind genital plates 2 and 3. In this respect the disc is very like that of Galeropygus and Clypeus. However Pronucleolites differs from those two taxa in having nucleolitid-style phyllodes, in which every third pore is insert to form a second discrete column of pore-pairs.
Barras, C. G. 2006. British Jurassic irregular echinoids. Monograph of the Palaeontographical Society no. 625 (part of volume 159 for 2005), 1-168, pls 1-14.