The Echinoid Directory

Cassiduloids with:

• single-pored phyllodes
• periproct aboral, opening into a posterior sulcus; not in contact with the apical disc
• phyllodes a simple irregular line of pores; no buccal pores
• test depressed towards peristome. Peristome without vertical walled entrance or distinct bourrelets; basicoronal plate short, no specialized perioral spines and tuberculation.

Cretaceous (Albian) to Recent of New Zealand, Australia, Europe, and Africa.

The characteristic phyllode plating, with a single irregular line of pores, and plating either simple or with occasional small adradial demiplates, immediately distinguishes Apatopygidae from other forms with an aboral periproct and anal sulcus, such as the nucleolitids and Petalobrissus. A similar plating is found in Plesiolampadidae, but in that group the periproct is inframarginal. Faujasiidae are most readily distinguished by their elongate basicoronal plate that is typically tooth-like and projecting.