The Echinoid Directory

Contributed by Andreas Kroh, November 2011

Family Eupatagidae Lambert, 1905


 Micrasterine spatangoids with:

  • ethmolytic apical disc;
  • petals flush, bowed, tapered distally and with perradial zone separating pore-pair columns wider than pore-pairs;
  • anterior petals with reduced pore-pairs in anterior column adapically;
  • labral plate elongate and wedge-shaped; extending to rear of second ambulacral plate or beyond;
  • sternal plates short and triangular;
  • episternal plates opposite and strongly indented to rear; ambulacral plate 6 laterally elongate and indenting posterior interambulacrum;
  • first pair of post-episternal plates also paired and opposite;
  • subanal fasciole typically developed and shield-shaped.
Range Eocene to Recent; Indo-Pacific.
Remarks  Distinguished from Spatangidae and Echinocardiidae by their long, wedge-shaped labral plate and short triangular sternum. Resembling Loveniidae in plastron structure but with more strongly indented episternal plates, a shield-shaped subanal fasciole and usually with occluded plates at the ends of the posterior petals.