The Echinoid Directory

Holectypoida with:

• periproct on oral surface, separated from peristome by only a relatively few plates
• apical disc compact with five genital plates, the posterior either with or without a gonopore.

 Early Jurassic (Pliensbachian) to Late Cretaceous (Maastrichtian); worldwide.

The suborder Holectypina and the family Holectypidae currently have the same taxonomic membership. The group is readily recognisable from its outset in the Early Jurassic by its circular outline, orally positioned periproct and characteristic apical disc structure. It contains a number of very commonly encountered fossil genera.