Contributed by Andrew Smith, October 2011
|Range||Late Triassic to Recent, worldwide|
|Species Included||Includes all Euechinoidea with the exception of the Echinothurioida, i.e. Carinacea, and four small orders previously grouped together as the Aulodonta (Diadematoida, Micropygoida, Aspidodiadematoida and Pedinoida).|
|Remarks||Regular echinoid members of this clade are distinguished from Cidaroidea by the presence of ambulacral plate compounding and from Echinothurioida by the presence of a single pair of buccal plates and tube-feet to each ambulacral zone on the peristome.
The following taxon is currently too poorly known to place with certainty:
Smith, A. B. 1981. Echinoid Palaeobiology. George Allen & Unwin, London.
Kroh, A. & Smith, A. B. 2010. The phylogeny and classification of post-Palaeozoic echinoids. Journal of Systematic Palaeontology 8, 147-212.