The Echinoid Directory

Family Micropygidae Duncan, 1889, p. 56

Diagnosis

Mycropygoida with:

  • test depressed in profile; coronal plating weakly imbricate
  • apical disc small; monocyclic; genital plates strongly projecting interradially. Periproctal plating well-developed
  • ambulacral plating trigeminate, with an enlarged element and two smaller demiplates
  • pore-pairs biserial at ambitus, tending to become irregularly uniserial close to the peristome and apex
  • interambulacral plates with multiple subequal tubercles
  • sphaeridial pit close to every third pore-pair from peristome to apex
  • aboral tube-feet from outer series of aboral pore-pairs with greatly expanded umbrella-like tube-feet of unique structure
  • tubercles perforate and non-crenulate
  • peristome small; buccal notches extremely sharp and deep, with associated tags
  • spines non-verticillate and hollow.
Range
Early Eocene to Recent; Indo-Pacific.
Classification and/or Status Acroechinoidea, Micropygoida
Remarks Duncan, P. M. 1889. A revision of the genera and great groups of the Echinoidea. Journal of the Linnean Society, Zoology 23, 1-311.

Mortensen, T. 1940. A Monograph of the Echinoidea. III, 1. Aulodonta, with Additions to Vol. II (Lepidocentroida and Stirodonta). C. A. Reitzel, Copenhagen, 370 pp.