The Echinoid Directory

Contributed by Philippe Nicolleau, April 2009

Masrouraster Vadet, Nicolleau & Reboul, 2008, p. 15.

Diagnostic Features
  • Test depressed and ambitus rounded.
  •  Apical system dicyclic and all the genital plates very large.
  • Ambulacra straight, widest ambitally; plating trigeminate with all the plates equal; pore-pairs uniform and undifferentiated, arranged uniserially until close to the peristome where they become slightly offset to form incipient phyllodes.
  • Primary ambulacral tubercle on each compound plate, except adapically where there are only granules.
  • Interambulacral with several tubercles abreast on ambital and adoral plates. Only granules adapically.
  • Ambulacral and interambulacral tubercles similar in size; perforate and non-crenulate.
  • Peristome very large, more than half of test diameter.
  • Spines and lantern unknown.
Distribution   Lower Jurassic, Pliensbachian (Domerian) of the High Atlas, Morocco.
Name gender masculine
Type Masrouraster ouhouissi Vadet, Nicolleau & Reboul 2008, p. 16, by  original designation.
Species Included
  • Only the type species.
Classification and/or Status
Monotypic
Remarks Remarkably similar to Acrosaster from the Callovian, differing in having two to three primary tubercles on subambital interambulacral plates and in having perforate tubercles.  Vadet et al. (2008) placed this as either an orthopsid or a pedinid, but as Brochechinus also has perforate tubercles, it is probably best grouped with Acrosaster as a primitive Glypticidae.
 
Vadet, A., Nicolleau, P. & Reboul, R. 2008. Masrouraster nov. gen. du Domerien de l'Atlas Marocain. Annales de la societe d'Histoire Naturelle du Boulonnais 6 (2), 15-17.