Sphaerocystites-Pseudocrinites Assoc., Middle Keyser Limestone (Silurian of the United States)

Where: West Virginia (39.5° N, 79.0° W: paleocoordinates 33.4° S, 42.6° W)

• coordinate based on political unit

• basin-level geographic resolution

When: Eccentricosta jerseyensis zone, Keyser Limestone Formation, Pridoli (423.0 - 419.2 Ma)

• "Latest Silurian (Pridolian), middle portions of the Keyser Limestone ('Spirifer' modestus-cystid Subzone of Eccentricosta jerseyensis Zone of Schuchert et al. 1913)."

• member-level stratigraphic resolution

Environment/lithology: deep subtidal ramp; bioturbated, shelly/skeletal, gray, blue, argillaceous wackestone and bioturbated, shelly/skeletal, gray, blue, argillaceous packstone

• "Fossils commonly articulated...intact thecae indicate rapid burial pulses. most of these at shaley partings within thick-bedded, more pure carbonates, generally sorted calcarenites. The aparent upward shoaling of this zone into the Gypidula coeyamensis-bearing packstones and grainstones (BA 3) suggests...outer BA 3 to Ba 4...."

•SEP environmental call based on given information

• "Richly fossiliferous bluish-gray nodular, somewhat argillaceous limestones characterize the Keyser Formation 'cystoid subzone'. Nodular wacke- to packstone lithologies indicate prevalent low energy conditions with a biooturbated substrate; cystoids apparently attached by holdfasts to bits of skeletal debris..."

Primary reference: T. J. Frest, C. E. Brett, and B. J. Witzke. 1999. Caradocian-Gedinnian echinoderm associations of Central and Eastern North America. Paleocommunities--a case study from the Silurian and Lower Devonian 638-783 [M. Foote/K. Koverman/P. Wagner]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 26825: authorized by Michael Foote, entered by Michael Foote on 05.11.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
unclassified
  -
Jaeckelocystis spp.
Jaeckelocystis spp.
three species
Gastropoda
 Euomphalina - Platyceratidae
Naticonema sp.
Naticonema sp. Perner 1903 snail
Strophomenata
 Orthotetida - Schuchertellidae
"Schuchertella" deckerensis
Rhynchonellata
 Atrypida - Atrypidae
Atrypa "reticularis"
Atrypa "reticularis" Linnaeus 1758
 Rhynchonellida - Uncinulidae
Uncinulus convexorus
Bryozoa
  -
Bryozoa indet.
Bryozoa indet. Ehrenberg 1831
ramose
Stenolaemata
 Cystoporata - Fistuliporidae
Fistuliporidae indet.
 Rhombifera - Callocystitidae
Sphaerocystites spp., Lepocrinites sp., Tetracystis sp., Pseudocrinites spp.
Sphaerocystites spp. Hall 1859
four species
Lepocrinites sp. Conrad 1840
Tetracystis sp. Schuchert 1904
Pseudocrinites spp. Pearce 1843
eight species
Crinoidea
 Calceocrinida - Calceocrinidae
Synchirocrinus keyserensis
 Myelodactylida - Myelodactylidae
Myelodactylus keyserensis
 Taxocrinida - Taxocrinidae
Protaxocrinus sp.
Protaxocrinus sp. Springer 1906 Sea lily
 Sagenocrinida - Nipterocrinidae
Pycnosaccus sp.
 Sagenocrinida - Icthyocrinidae
Clidochirus sp.
 Diplobathrida - Rhodocrinitidae
Sphaerotocrinus sp.
Sphaerotocrinus sp. Goldring 1923 Sea lily
 Monobathrida - Eucalyptocrinitidae
Eucalyptocrinites sp.
Eucalyptocrinites sp. Goldfuss 1831 Sea lily
 Monobathrida - Hapalocrinidae
Hapalocrinus sp.
Hapalocrinus sp. Jaekel 1895 Sea lily
 Monobathrida - Scyphocrinitidae
Scyphocrinites sp.
Scyphocrinites sp. Zenker 1833 Sea lily
 Monobathrida - Periechocrinidae
Periechocrinus sp.
Periechocrinus sp. Morris 1843 Sea lily