The figure below shows the distribution of samples containing the brachiopod Sowerbyella.
Sowerbyella is a common strophomenid brachiopod in the MRV strata.
- Sowerbyella Jones, 1928 [*Leptaena sericea Sowerby, 1839]
- Parvicostellae either smooth or slightly beaded and variably segregated; ventral muscle scar small and bilobed, bounded posterolaterally by short dental plates and anteromedianly by pair of divergent ridges bifurcating from short median ridge bearing adductor scars; brachial valve with pair of strong submedian septa flanked by raised suboval areas, median ridge variably developed.
Ord. - L. Sil., cosmopolitan
- Family Sowerbyellidae Opik, 1930
- Semicircular to semioval, unequally parvicostallate, with small pseudodeltidium, apical foramen rarely if ever persistent in adult shells. Small teeth rarely supported by dental plates and rarely supplemented by denticles; variably bilobed ventral muscle scar with deeply inserted lanceolate adductor scars; chilidial plates fused with small flat-lying socket ridges and median ridge-like cardinal process to form inverted V which overhangs subcircular deep depression in place of notothyrial platform; dorsal septa and lophophore platform variably developed; ventral and dorsal mantle canal patterns digitate to lemniscate.
Ord. - M. Dev.
- Order Strophomenida Opik, 1934
Treatise on Invertebrate Paleontology, H378-379