Phylum: Brachiopoda
Class: Strophomenata
Order: Strophomenida
Family: Sowerbyellidae (Opik, 1930)
Cincinnatian Genera: Sowerbyella, Eochonetes

Geologic Range
Ordovician (Llanvirn) – Devonian(Eifelian)

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

Characters of the Family

  • Concavoconvex
  • Weak dental plates
  • Wide lateral septa
  • Bema development variable
  • Undercut cardinal process

Published Descriptions

Treatise on Invertebrate Paleontology, Part H, Vol. 2 (2000):

  • Systematics:
    • Concavoconvex to resupinate profile; weak dental plates usually developed, sometimes absent; undercut cardinal process; side septa; bema usually developed

Cocks & Rong (1989):

  • Diagnosis: Undercut cardinal process. With wide side septa. With bema usually developed
  • Remarks: A bema is usually present in species assigned to this family, although it becomes better developed and thicker in gerontic individuals and is very often not seen in young specimens. In a few species it is not developed at all, for example in Sowerbyella sinensis, which on all other grounds can be unequivocally assigned to Sowerbyella. In most of the species of Sowerbyella itself, including S. sericea the type species, the bema is well developed. The family is divided into three subfamilies on the division of the bema and whether or not the cardinal process is differentiated into a separate recognizable structure, or whether, as in the Craspedelliinae, it is totally fused and inseparable from the other central structures on the brachial valve hinge line.
  • Subfamilies assigned: Sowerbyellinae Öpik, 1930; Craspedellinae subfam. nov.; Ptychoglyptinae Copper, 1956
  • Range: Llanvirn to Eifelian