Hemicystitidae

Classification
Phylum: Echinodermata
Class: Edrioasteroidea
Order: Isorophida
Family: Hemicystitidae (Bassler, 1936)
Cincinnatian Genus: Carneyella

Geologic Range
Ordovician – Early Carboniferous

Common Paleoecology
Hemicystitidae is an extinct family of stationary low-level epifaunal suspension feeders

Description of the Family

  • Peristome covered by 3-4+ plates
  • Theca flat, sac-like or turret-shaped
  • Theca composed of thin plates
  • Ambulacra normally 5 straight or curved
  • Single row of ambulacral floor plates

Published Descriptions

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

  • Peristome covered by ?3, 4, or more plates, ?3, 4 of which have definite arrangements; 3 meeting in center of peristomial region, 1 laying over posterocentral part of peristome, other 2 with 1 on each side of ambulacrum A; Theca flat, saclike or turret-shaped, composed of thin plates, attached permanently (or ?temporarily) to some foreign object by greater part of aboral surface; ambulacra normally 5, straight or curved; single row of ambulacral floor plates more or less overlapping proximally.

Carneyella