Contributed by Andrew Smith, August 2008
Diagnostic Features |
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Distribution | Jurassic (Bathonian-Oxfordian), Europe |
Name gender | masculine |
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 Monotypic. |
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. |