The Echinoid Directory

Contributed by Andrew Smith, December 2010

Order Micropygoida Kroh & Smith, 2010, p. 170

Diagnosis Acroechinoidea with:
  • coronal plating slightly flexible
  • apical disc small; monocyclic; genital plates strongly projecting interradially
  • ambulacral plating trigeminate, with an enlarged element and two smaller demiplates
  • pore-pairs biserial at ambitus
  • 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 Eocene to Recent, Indo-Pacific region
Species Included Only the family Micropygidae is included
Classification and/or Status Euechinoidea, Acroechinoidea
Remarks Phylogenetic analysis places this taxon at, or close to, the base of the Acroechinoidea.

Kroh, A. & A. B. Smith, 2010. The phylogeny and classification of post-Palaeozoic echinoids. Journal of Systematic Palaeontology 8, 147-212.