The Echinoid Directory

Family Monophorasteridae Lahille, 1896, p. 441


 Scutellidea with:

  • complex internal buttresses forming microcanal system around periphery;
  • four gonopores;
  • ambulacral zones very much wider than interambulacral zones at ambitus; pores and tube-feet confined to ambulacral zones;
  • petals well-developed;
  • basicoronal circlet pentastellate, with interambulacral elements strongly projecting;
  • periproct opening oral, between peristome and anal lunule;
  • anal lunule, situated posterior to the petals, but no ambulacral lunules;
  • food grooves well developed, bifurcating at edge of basicoronal circlet and finely subdivided distally.
 Oligocene to Miocene; South America.
Remarks A key-to-species of Monophorasteridae can be found in Mooi et al. (2016).

Mooi, R., Martínez, S.A., Del Río, C.J. (2016). A new South American Miocene species of 'one-holed' sand dollar (Echinoidea: Clypeasteroida: Monophorasteridae). Zootaxa. 4173(1): 45-54.