Dalmanellidae

Classification
Phylum: Brachiopoda
Class: Rhynchonellata
Order: Orthida
Family: Dalmanellidae (Schuchert, 1913)
Cincinnatian Genera: Cincinnetina, Dalmanella

Geologic Range
Lower Ordovician (Arenig) – Upper Devonian (Frasnian)

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

Description of the Family

  • Normally subcircular
  • Ventribiconvex (one valve is more convex than the other>
  • Unisulcate
  • Fascicostellate (Costellate patterns “lumped into bundles”)
  • Straight or curved ventral and dorsal interarea
  • If interior is visible, suboval, subtriangular to cordate muscle scars present
  • Brachiophores usually simple blades
  • Variably lobate cardinal process and shaft
  • Generally earlier taxa have fulcral plates
  • Adductor muscle scars rarely enclosed by diductor scars
  • Median ridges, septa, partitions and platforms may develop sporadically in dorsal valve

Published Descriptions

Treatise on Invertebrate Paleontology, Part H, Vol. 3 (2000):

    • Systematics
        Normally subcircular, ventribiconvex, unisulcare, fascicostellate dalmanelloids with short, straight or curved ventral and doral interarea; ventral interior normally with suboval, subtriangular to cordate muscle scars, with adductors rarely enclosed by diductors, and divergent dental plates; dorsal interior with variably lobate cardinal process and shaft; brachiophores commonly as simple blades, variably disposed with variably inclined brachiophore plates; fulcral plates common, mainly in earlier taxa; median ridges, septa, partitions, and platforms sporadically developed in dorsal valves; ventral and dorsal mantle canal systems commonly lemniscates.

Cincinnetina


Dalmanella