Eoplectodonta-Atrypa Subcommunity, Williamson Shale, West-Central N.Y. (Silurian of the United States)

Where: New York (43.2° N, 76.8° W: paleocoordinates 25.6° S, 45.7° W)

• coordinate based on political unit

• local area-level geographic resolution

When: Williamson Shale Formation, Telychian (438.5 - 433.4 Ma)

• Age based on correlation chart, Fig. 44.2. Found in both Williamson Shale and Willowvale Shale, which are lateral equivalents.

• formation-level stratigraphic resolution

Environment/lithology: offshore; gray, green shale and siltstone

• "Assemblage believed to occupy BA 4...grades continuously into Monograptid-Strophochonetes assemblage, which is BA 5...oxygen stress...BA 4-5 suggested by brachiopods...Ischadites on some bedding planes in Willowvale Shale containing [this community] [indicating photic zone]...tempestites well developed...hence, position within storm wave base indicated"

•

•2003:04:06 SEP Environmental/tectonic/sequence call based on description and Brett et al. (1998). Bulletin New York State Museum 491:89-143. "Williamson-Willowvale interval has been interpretted as the early (maximum) highstand of Sequence IV" (p.107). Also by Lin and Brett (1988). Stratigraphy and disconformable contacts of the Williamson-Willowvale interval; revised correlations of the late Llandovery (Silurian) in New York State. Northeastern Geology.10(3):241-253.

• "Most of the samples are obtained from greenish-gray to dark-gray shale...interbedded with nearly black laminated shales [Williamson]...tempestites; here lenticular masses of Atrypa and Eoplectodonta form bases of graded beds. Shells are overlain by small scale hummocky C-S siltstone..."

Primary reference: C. E. Brett. 1999. Wenlockian fossil communities in New York State and adjacent areas: Paleontology and Paleoecology. In A. J. Boucot, J. D. Lawson (eds.), Paleocommunities: A Case Study from the Silurian and Lower Devonian 592-637 [M. Foote/K. Koverman/J. Alroy]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 26865: authorized by Michael Foote, entered by Michael Foote on 06.11.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Chlorophyceae
  - Receptaculitidae
Ischadites planoconvexa
Rhynchonellata
 Atrypida - Atrypidae
Atrypa "reticularis"
Atrypa "reticularis" Linnaeus 1758
 Orthida - Dicoelosiidae
Dicoelosia sp.
Dicoelosia sp. King 1850
 Orthida - Rhipidomellidae
Dalejina sp.
Dalejina sp. Havlicek 1953
 Orthida - Dalmanellidae
Resserella sp.
Resserella sp. Bancroft 1928
Strophomenata
 Strophomenida - Rafinesquinidae
Leptaena sp.
Leptaena sp. Dalman 1828
 Strophomenida - Sowerbyellidae
"Eoplectodonta transversalis" = Eoplectodonta (Eoplectodonta) transversalis
"Eoplectodonta transversalis" = Eoplectodonta (Eoplectodonta) transversalis Wahlenberg 1818
Bryozoa
  -
Bryozoa indet.
Bryozoa indet. Ehrenberg 1831
ramose forms
Stenolaemata
 Fenestrata -
Fenestrata indet.
Fenestrata indet. Elias and Condra 1957
Anthozoa
 Cystiphyllida - Palaeocyclidae
Palaeocyclus sp.
Palaeocyclus sp. Milne-Edwards and Haime 1849 horn coral