The Echinoid Directory

Family Pourtalesiidae A. Agassiz, 1881, p. 124


 Urechinid holasteroids with:

  • thin test;
  • orthosternous plastron (labral plate followed by single symmetrical sternal plate then a pair of episternal plates). Labrum usually separated from sternal plate by ambulacral plates;
  • no rostral plate;
  • apical disc 'compact' with single anterior genital plate followed by ocular plates II and IV both of which house gonopores. Posterior oculars disjunct from remainder of disc.
Late Cretaceous (Maastrichtian) to Recent; worldwide.