The Echinoid Directory

Pseudosorella Etallon, 1859, p. 415

[=Pseudodesorella Cotteau, 1867, p. 325 (objective); =Neoclypeus de Loriol, 1901, p. 33, type species Neoclypeus syriacus de Loriol, 1901; =Notopygus Pomel, 1883, p. 58, type species Nucleolites amplus L. Agassiz in Agassiz & Desor, 1847; Primipygus Vadet, 2007, p. 192, type species Nucleolites richardsoni Talbot Paris, in Richardson & Talbot Paris, 1908 ]

Diagnostic Features
  • Test medium to large, circular in outline; inflated, with rounded margin, adorally ambulacra depressed. In profile tallest close to the posterior and sloping anteriorly.
  • Apical system central to slightly anterior, tetrabasal; genital plate 2 large and central; catenal plate(s) present (primitive form).
  • Petals broad, long, wide interporiferous zones, narrow poriferous zones, open, but tapering distally, pores conjugate, outer pore elongated into slit, inner pore round; all ambulacral plates double pored.
  • Periproct supramarginal, in contact with apical system, opening into deep groove extending from apical system to posterior margin.
  • Peristome central or slightly anterior, pentagonal, wider than high.
  • Bourrelets hardly developed; just a narrow band of tubercles at lip of peristome.
  • Phyllodes well developed, slightly bowed towards peristome; inner and outer series in each half ambulacrum.
  • No buccal pores.
Middle to Upper Jurassic (Bathonian-Oxfordian); Europe and Middle East.
Name gender feminine
Desoria orbignyana Cotteau, 1855, p. 227; by monotypy.
Species Included
  • P. orbignyana Cotteau, 1855; Oxfordian, France.
  • P. syriaca (De Loriol, 1901); Jurassic, Syria.
  • P. amplus (L. Agassiz in Agassiz & Desor, 1847); Bathonian, France.
  • P. pyramidalis (McCoy, 1848); Bajocian-Oxfordian, western Europe
  • P. elongata (Cotteau & Triger, 1857); Bathonian-Callovian, Europe
  • P. woodwardii (Wright, 1854); Bajocian-Oxfordian, England, France
Classification and/or Status
Irregularia; Neognathostomata; \'clypeid\'.

Pseudosorella is distinguished from Clypeus by its phyllode structure: in Pseudosorella pore-pairs are arranged into an inner and outer series, in Clypeus the pores are in arcs of three and form a single broad band.

P. M. Kier. 1962. Revision of the cassiduloid echinoids. Smithsonian Miscellaneous Collections, 144 (3) 262 pp.

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.

Etallon, A. 1859. Études paléontologiques sur le Haut Jura.  Mémoires de la Société d’Émulation de Doubs, (3) 3, p. 415.