The Echinoid Directory

Caenocidaris Thiery, 1928, p. 180

[=Besairiecidaris Lambert, in Besairie, 1936, p. 117, type species Besairiecidaris ankarensis Lambert, 1936; =Chesniericidaris Vadet, 2004, p. 27, type species Cidaris wrightii Desor, 1855.]

Diagnostic Features
  • Test depressed (height less than 50% diameter).
  • Apical disc large, about 50% test diameter; plating unknown.
  • Interambulacra composed of ca. five plates per series; one small rudimentary plate in each zone adapically. Interambulacral plates approximately as wide as tall, with large primary tubercle. Mamelons large and increasing in size adapically; with small perforation on ambital and adapical tubercles only (adoral tubercles imperforate); platform narrow, smooth on adoral side but distinctly crenulate around adapical margin of ambital and adapical tubercles. Areoles circular; hardly incised.
  • Scrobicular tubercles coarse and strongly differentiated. Extrascrobicular granules also rather coarse and only really developed interradially.
  • Ambulacra narrow, sinuous, the pore zones a little depressed and about as wide as the perradial tuberculate zone. Pore-pairs non-conjugate, the two pores separated by a partition that is narrower than an individual pore.
  • A primary tubercle to every plate from the ambitus adapically, but adorally every second tubercle enlarged; the perradial zone very narrow with just the occasional granule. All ambulacral elements reaching the perradius but alternately taller and shorter adorally.
  • Perignathic girdle of apophyses.
  • Spines short, stout and fusiform with distinct neck and distally tapering point. Shaft ornamented by beaded ribs proximally, and more irregular pustules distally.
Middle Jurassic (Aalenian, Bajocian); Europe, Madagascar.
Name gender feminine
Cidaris cucumifera Agassiz, 1840, p. 70, by original designation.
Species Included
Classification and/or Status

Cidaroida, Psychocidaridae.

Probably paraphyletic.


Balanocidaris differs only in having finer scrobicular tubercles and more incised areoles but is otherwise very similar; possibly only worth distinguishing at subgenus level.

Thiery, P. 1928. Considerations phylogenetiques sur les Cidaridae (postumously published by Coenot & Lambert). Archives de Zoologie experimental et generale 67. Notes et Revue 4, 179-181.

Vadet, A. 1991. Revision des "Cidaris" du Lias et du Dogger Europeens. Memoires de la Societe du Bolognnais 10, 1-167, pls 1-9.