The Echinoid Directory

Parastomechinus Philip, 1963, p. 1111

Diagnostic Features
  • Test wheel-shaped, flattened below and above.
  • Apical disc small, pentagonal; dicyclic.
  • Ambulacra trigeminate; plate compounding acrosaleniid with two elements overlapped by a primary tubercle and a third simple element. All elements reach the perradial suture. Pore-pairs uniserially arranged. Adapical plates simple and without well developed primary tubercles.
  • Interambulacral plates a little wider than tall, with singlel primary tubercle occupying much of the plate. Secondary tubercles around edges of the plate.
  • Ambulacral and interambulacral tubercles of similar size; iPrimary tubercles imperforate and non-crenulate; mamelon rather massive.
  • No aboral naked interradial zone.
  • Peristome large, a little sunken; buccal notches small but sharp.
  • Spines and lantern unknown; no primordial interambulacral plate.
Middle Jurassic, USA.
Name gender masculine
Parastomechinus brightoni Philip, 1963, p. 1112, by original designation (type destroyed).
Species Included
  • Only the type species.
Classification and/or Status

Acroechinoidea, Carinacea, Pseudodiadematidae.

Monotypic; subjective junior synonym of Hessotiara Pomel, 1883.

Philip, G. 1963. A new regular echinoid from the Jurassic of Wyoming, USA. Journal of Paleontology 37, 1110-1115.