Phylum: Brachiopoda
Class: Rhynchonellata
Order: Rhynchonellida
Family: Orthorhynchulidae (Cooper, 1956)
Cincinnatian Genera: Orthorhynchula

Geologic Range
Late Ordovician – Middle Silurian

Common Paleoecology
Orthorhynchulidae is an extinct family of stationary epifaunal suspension feeders

Description of the Family

  • Open delthryium or incipient deltidal plates
  • Reduced dental plates
  • Ventral interarea present
  • Hinge plates slope medially
  • Cardinal process septiform, lobed, or branching

Published Descriptions

Treatise on Invertebrate Paleontology, Part H, Vol. 4 (2002):

  • Rhynchotrematoidea with delthyium open or with incipient deltidial plates; ventral interarea commonly present; dental plates reduced; hinge plates slope medially to join septalium that is sessile or supported on low median septum; cardinal process septiform, lobed, or branching.