The Echinoid Directory

Order Salenioida Delage & Herouard, 1903, p. 235

Diagnosis

 Regular echinoids with:

  • apical disc incorporating a single large suranal plate as an integral part of the adult disc;
  • ambulacral plates with all elements reaching the perradius; often bigeminate but may be unigeminate or trigeminate;
  • ambulacra narrow and tubercles much smaller than those of interambulacral zones and imperforate;
  • interambulacral plates with single large primary tubercle surrounded by differentiated scrobicular tubercles.
Range
Middle Jurassic to Recent; worldwide.
Remarks
Salenioids are a readily recognizable clade of echinoids because of their very distinctive apical disc structure. Acrosaleniids differ in having perforate ambulacral tubercles, at least orally, and most have multiple suranal plates.