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
