The Echinoid Directory

• The type species is based on a small individual, just 15 mm in diameter:

• Test relatively tall and thin-shelled.
• Apical disc about 50% test diameter; slightly larger than peristome. Plating unknown.
• Interambulacra with 6-7 plates in a series. Primary tubercles perforate and crenulate, the adapical ones being more strongly crenulate. Mamelons small but enlarging adapically. Areoles circular, not incised; separated at ambitus and adapically where they are large and circular; confluent adorally where they are smaller.
• Scrobicular circles differentiated on ambital and adapical plates but absent from adoral plates. No extrascrobicular zones; adoral plates with a few secondary tubercles.
• Ambulacral zones more or less straight. Pore zones flush; slightly narrower than perradial tuberculate zone. Aboral pore-pairs subconjugate, the pores separated by a raised interporal partition that is at least as wide as a pore; adoral pores non-conjugate with narrow interporal partition. All plates reach the perradius. A larger tubercle on every second or third plate from apex to peristome.
• Perignathic girdle not seen.
• Peristome plating unknown.
• Spines unknown for certain in type species.

Middle to Upper Jurassic (Bajocian-Kimmeridgian); Europe.

Cidaris bajocensis Cotteau, 1875, p. 52, by original designation. Neotype designated by Vadet (1991, p. 138): Museum National d'Histoire Naturelle, Paris J01687.

• Vadet (1991), when erecting this genus, included four species:

   

• A. bouchardi (Wright, 1851); Aalenian, UK, France.
• A. spinulosa (Cotteau, 1875); Bajocian, France, UK [treated by Vadet as a senior synonym of Cidaris bajociensis Cotteau].
• A. microstoma (Cotteau, 1875); Bathonian-Callovian, France, UK.
• A. leberti (Vadet, 1989); Callovian, France.

Cidaroida, Polycidaridae.

Treated here as a subgenus of Paracidaris.

This taxon was redescribed by Vadet (1991), who  selected the neotype. Unfortunately, the type species is based on a juvenile and thus it and all higher taxa on which it is based are difficult to compare meaningfully with others. It is by no means certain that the neotype is conspecific with the type of Cidaris spinulosa, as claimed by Vadet (1991). If Vadet is correct, then Anisocidaris is a senior subjective synonym of Nenoticidaris, since both have a similar ambulacral structure.

Zbindenicidaris differs in having heterogeneous ambulacral tuberculation developed only adorally; on ambital and adapical plates each has a single, uniformly sized marginal tubercle.

Thiery, P. 1928. Considerations phylogentiques sur les Cidaridae. 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 academique du Boulonnais 10, 1-176.