Edrioasteroidea

Classification
Phylum: Echinodermata
Class: Edrioasteroidea (Billings, 1858)
Cincinnatian Orders: Isorophida

Geologic Range
Cambrian – Permian

Common Paleoecology
Edrioasteroidea is an extinct class of stationary low-level epifaunal suspension feeders

Characteristics of the Class

  • Multiplated echinoderms with normally well-developed quinqueradiate endothecal ambulacral system
  • No thecal pores, but pores may be present between ambulacral elements
  • No arms or brachiols
  • Anal opening in posterior interradus, usually covered by valvula pyramid
  • Unstalked

Published Descriptions

Treatise on Invertebrate Paleontology, Part U, Vol. 3(1) (1966):

  • Many-plated echinoderms with well-developed (normally) quinqueradiate endothecal ambulacral system; no thecal pores, but pores may be present between ambulacral elements (thus not piercing substance of plates); no arms or brachioles; anal opening in posterior interradius, generally covered by valvula pyramid; a third aperture, interpreted generally as a hydropore, may be recognizable between mouth and anus; unstalked.

Isorophida