- 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.
||Eocene to Recent, Indo-Pacific region
||Only the family Micropygidae is included
|Classification and/or Status
||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.