Lower Jurassic (Pliensbachian) to Lower Cretaceous (Valanginian); Europe, North Africa, Madagascar.
|Classification and/or Status||Cidaroidea, Cidaroida|
Distinguished from almost all other cidaroids by having biserially offset pore-pairs. The structure of the pore-pairs, in which the two pores are separated by a prominent raised interporal partition, suggests this group is derived from members currently included in the Polycidaridae. Tetracidaris has a similar ambulacral pore-pair arrangement but differs in having four columns of interambulacral plates at the ambitus.