Isorophus cincinnatiensis
Classification
Phylum:Echinodermata
Class:Edrioasteroidea
Order:Isorophida
Family:Isorophidae
Genus:Isorophus
Species: Isorophus cincinnatiensis (Roemer, 1851)
Taxonomic Details
Formerly: Agelacrinus cincinnatiensis, Agelacrinites cincinnatiensis, Carneyella cincinnatiensis, Lepidodiscus cincinnatiensis
Includes: Agelacrinus holbrooki, Isorphus holbrooki, Carneyella holbrooki
Includes: Agelacrinus holbrooki, Isorphus holbrooki, Carneyella holbrooki
Stratigraphic Occurrences
Stratigraphic Description
Sequences (Formations)
- C5 Sequence (Lower Whitewater)
- C4 Sequence (Arnheim)
- C3 Sequence (Corryville)
- C2 Sequence (Bellevue)
Identification in Hand Sample
- Moderate to large domed theca
- Smaller secondary ambulacral cover plates
- Long, curved ambulacra
- May exceed 2.5 cm in diameter
- Double biseries of plates along the ambulacra and 4 primary oral plates
Isorophus cincinnatiensis from unknown formation of Hamilton County, Ohio (OUIP teaching collection)
Published Description
Holland (UGA Strat Lab, 2013):
- Moderate to large domal theca, with relatively smaller secondary ambulacral cover plates
Davis (1998):
- Edrioasteroid. Characterized by numerous plates and long, curved ambulacra. May exceed 2 ½ cm (1”) in diameter. Fairmount up to Mount Auburn.
Fossils of Ohio (1996):
- Can be distinguished by having double biseries of plates along the ambulacra and four primary oral plates.
Bell (1974):
- Moderate to large diameter; five or more secondary orals; primary ambulacral coverplates distinctly larger externally than secondaries; secondaries rarely reaching adradial suture line externally; interambulacrals proportionately of moderate size.