Articulate Brachiopods, Placotriplesia Beds, Fitzhugh Mbr., Clarita Fm., Okla. (Silurian of the United States)

Where: Oklahoma (34.3° N, 96.8° W: paleocoordinates 25.6° S, 63.0° W)

• coordinate based on political unit

• local area-level geographic resolution

When: Fitzhugh Member (Clarita Formation), Wenlock (433.4 - 427.4 Ma)

• Placotriplesia beds are in the upper part of Fitzhugh Member, but it is not clear from data presented by Amsden whether a Sheinwoodian or Homerian age is more likely.

• group of beds-level stratigraphic resolution

Environment/lithology: deep subtidal ramp; shelly/skeletal grainstone and packstone

• Amsden suggests condition of shells indicates low-energy environment, much material possibly in situ. No evidence of reefs or buildups.

•SEP environmental call based on given info and on Amsden (1968) JP 42 sup. to 3

• "...limestone with moderately thin, uniform bedding...Basically it is a bioclastic, grain-supported rock ranging from a grainstone to a packstone. The cementing material may be spar or micrite...commonly pink...crinoidal...[in places approaching a marlstone]..."

Collection methods: Text-fig. 13, Placotriplesia beds.

Primary reference: T. W. Amsden. 1968. Articulate brachiopods of the St. Clair Limestone (Silurian), Arkansas and the Clarita Formation (Silurian), Oklahoma. Paleontological Society Memoir 1:1-117 [M. Foote/M. Foote/M. Foote]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 26025: authorized by Michael Foote, entered by Michael Foote on 01.10.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

• Articulate brachiopods only.
Strophomenata
 Productida - Strophochonetidae
Strophochonetes sp. Muir-Wood 1962
 Orthotetida - Triplesiidae
 Strophomenida - Leptestiidae
 Strophomenida - Rafinesquinidae
Leptaena sp. Dalman 1828
 Strophomenida - Amphistrophiidae
Amphistrophia sp. Hall and Clarke 1892
Chileata
 Dictyonellida - Eichwaldiidae
"Dictyonella sp." = Eodictyonella
"Dictyonella sp." = Eodictyonella Wright 1994
Rhynchonellata
 Athyridida - Rhynchospirinidae
 Athyridida - Meristellidae
 Spiriferida - Delthyrididae
 Spiriferida - Cyrtinopsidae
 Rhynchonellida - Trigonirhynchiidae
 Rhynchonellida - Rhynchotrematidae
 Orthida - Orthidae
 Orthida - Hesperorthidae