The Echinoid Directory

Roseicidaris Vadet, 1991, p. 86

[?=Reboulicidaris Vadet & Nicolleau, 2005, p. 7, type specie Reboulicidaris rebouli Vadet & Nicolleau, 2005.]

Diagnostic Features
  • Test small, largest fragment suggests test diameter of only 18 mm; known only from fragments.
  • Apical disc and peristome size and plating unknown.
  • Interambulacra with five plates in a column. Adoral primary tubercles imperforate and non-crenulate; ambital and adapical tubercles non-crenulate and with small or rudimentary perforation. Mamelons large; increasing in size adapically.
  • Areoles circular, incised, separated throughout. Scrobicular tubercles differentiated; extrascrobicular tubercles dense and uniform.
  • One adapical plate in each zone tall and narrow, lacking a primary tubercle.
  • Sutural pits developed on horizontal interambulacral sutures.
  • Ambulacra weakly sinuous; pore zone a little incised; pore-pairs narrow, non-conjugate. Perradial zone narrow, with only a single primary tubercle per plate; tubercles appear uniform.
  • No primary spines found attached, but isolated spines in same bed are rather short and weakly fusiform. Collar virtually absent; shaft ornamented with rows of thorns.
  • Perignathic girdle of apophyses.
Distribution
Lower Jurassic (Pliensbachian - Toarcian); France, Morocco
Name gender feminine
Type
Cidaris morieri Cotteau, 1875, p. 29, by original designation.
Species Included
  • R. morieri (Cotteau, 1875); Lower Toarcian, France. 
  • R. rebouli (Vadet & Nicolleau, 2005); Upper Pliensbachian, Morocco.
Classification and/or Status

Cidaroidea, Psychocidaridae

 

Remarks

The large mamelons and rudimentary perforation together with the sutural pits and the distinctive narrow adapical interambulacral plate lacking a tubercle all identify this as a psychocidarid. It is distinguished from Balanocidaris and all other Jurassic forms by its weakly fusiform spines and its lack of alternately enlarged ambulacral tubercles.

The type species is based on very small individuals. Reboulicidaris was established for a much larger species but its test construction is very similar, in having  highly elongate adapical interambulacral plates and narrow perradial ambulacral zones.  Spine morphology is also very similar.

Vadet, A. 1991. Revision des "Cidaris" du Lias et du Dogger Europeens. Memoires de la Societe academique du Boulonnais 10, 1-176.