Phylum: Echinodermata
Class: Crinoidea
Order: Disparida
Family: Iocrinidae (Moore & Laudon, 1943)
Cincinnatian Genera: Iocrinus

Geologic Range
Middle Ordovician – Late Ordovician

Common Paleoecology
Iocrinidae is an extinct family of stationary intermediate-level epifaunal suspension feeders

Description of the Family

  • Compound radial in ray only
  • Superradial supports anal X on left side with free arm on right
  • Arms with many isotomous branches
  • Column transversely pentagonal to pentastellate
  • Composed of alternating thick and thin columnals

Published Descriptions

Treatise on Invertebrate Paleontology, Part T (1978):

  • Compound radial in C ray only; superradial supports anal X on left side and free arm on right. Arms with many isotomous branches. Column transversely pentagonal to pentastellate, composed of alternating thick and thin columnals.