Phylum: Mollusca
Class: Bivalvia
Order: Actinodontida
Family: Cycloconchidae (Ulrich, 1884)
Cincinnatian Genera: Cycloconcha

Geologic Range
Middle Ordovician – Late Ordovician

Common Paleoecology
Cycloconchidae is an extinct family of facultatively mobile infaunal suspension feeders

Description of the Family

  • Ovoid shape
  • Shell laterally compressed (isomyarian)
  • Submedian beak
  • Few elongate teeth below beak

Published Descriptions

Treatise on Invertebrate Paleontology, Part N, Mollusca 6(1 of 3) (1969):

  • Amphidetic, with median cardinals and laterals in front of and behind beaks; those of RV stronger than those of LV.
  • (Superfamily characteristics) (Cycloconchacea) Ovoid, more or less isomyarian shells with submedian (never terminal) beaks; lacking radial ornamentation; dentition consisting of few elongate teeth below beaks increasing in length toward anterior and posterior margins of hinge (M. Cam. – U. Dev.)