NYSM locality 5897 (Ordovician of the United States)

Also known as section SB-R; Rochdale Fm., "Fort Ann Fm."; east of Smiths Basin, Washington Co.

Where: Washington County, New York (43.4° N, 73.5° W: paleocoordinates 31.9° S, 67.7° W)

• coordinate stated in text

• small collection-level geographic resolution

When: Rochdale Formation (Beekmantown Group), Stairsian (485.4 - 478.6 Ma)

• "As concluded by Landing & Westrop (2006, p. 967), the Rochdale Formation is the senior synonym of the ‘Fort Ann Formation’, a unit for which a type section was never specified and which was named for a village that is actually located on Late Ordovician synorogenic flysch. Further north in western Vermont, the Bascom Formation (Cady, 1945) includes three divisions that indicate lateral equivalency and junior synonymy with the upper Tribes Hill, Rochdale and Fort Cassin formations (Landing, Westrop & Van Aller Hernick, 2003)." (Kröger & Landing, 2008 p. 492)

• member-level stratigraphic resolution

Environment/lithology: shallow subtidal; stromatolitic, shelly/skeletal reef rocks and dolomite

• "These thrombolitic- and intraclast dominated horizons are very similar to the cephalopod bearing beds of the underlying upper Tribes Hill Formation (Kröger & Landing, 2007) and represent the shoaling interval of a highstand systems tract."
• "A poorly exposed, 38.3 m thick section measured along the north side of Rte 149 through the Rochdale includes 11.3 m of low sucrosic dolostone ledges with a dolomitic lime mudstone (10.4–10.8 m) in the lower Rochdale followed by a long covered interval (11.3–36.0 m). The top of the formation (36.0–38.8 m) features massive thrombolites, with poorly preserved gastropods, cephalopods and trilobites, that are mantled by planar to micro-cross-laminated dolostone."

Size class: macrofossils

Preservation: cast

Collected by R. H. Flower; reposited in the NYSM

• "The bulk of the material collected by R. H. Flower from the Rochdale Formation in the 1940s came from the Smith Basin section, and is reposited under NYSM Paleontology Collection locality number 5897 (146 specimens). An examination of the currently exposed parts of the Smith Basin succession indicates that Flower’s cephalopods did not come from the lower part of the sequence, and the lithology is more suggestive of the top." (Kröger & Landing, 2008 p. 494).

•"Most of the cephalopods discussed herein were collected in the 1940s by R. H. Flower during his tenure at the New York State Museum (NYSM). Flower (1955, 1956, 1964a, 1976) repeatedly referred to this material in the NYSM Paleontology Collection [...]" (ibid. p. 491).

Primary reference: B. Kröger and E. Landing. 2008. Onset of the Ordovician cephalopod radiation - evidence from the Rochdale Formation (middle Early Ordovician, Stairsian)in eastern New York. Geological Magazine 145(4):490-520 [B. Kröger/B. Kröger]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 89491: authorized by Björn Kröger, entered by Torsten Liebrecht on 26.05.2009

Creative Commons license: CC BY (attribution)

Taxonomic list

Cephalopoda
 Endocerida - Proterocameroceratidae
Paraendoceras depressum n. sp. Kröger and Landing 2008
NYSM 17513 (holotype)
Paraendoceras wappingerense Ulrich et al. 1944
NYSM 17502, 17503, 17506 to 17511 + 18 unnumbered specimens
Mcqueenoceras aff. jeffersonense Ulrich and Foerste 1936
NYSM 17491
Exoclitendoceras rochdalense n. gen. n. sp. Kröger and Landing 2008
NYSM 17499 (holotype), 17500, 17501 (paratypes)
Clitendoceras saylesi Ulrich and Foerste 1936
NYSM 17493 to17496 + 19 unnumbered specimens
 Ellesmerocerida - Ellesmeroceratidae
Ectenolites sp. Ulrich and Foerste 1935
NYSM 17487
Bassleroceras sp. Ulrich and Foerste 1936
"Bassleroceras sp. A"; NYSM17483, 17484
Bassleroceras champlainense n. sp. Kröger and Landing 2008
NYSM 17468 (holotype), 17469, 17475 (paratypes) + 57 additional specimens for which no catalogue numbers are given
Bassleroceras vassarina Dwight 1884
NYSM 17470, 17471, 17479, 17485
Bassleroceras triangulum n. sp. Kröger and Landing 2008
NYSM 17477 (holotype), 17478 (paratype)
Bassleroceras smithbasinense n. sp. Kröger and Landing 2008
NYSM 17473 (holotype), 17474, 17475 (paratypes)
 Ellesmerocerida -
Vassaroceras henrietta Dwight 1884
NYSM 17489, 17490
 Multiceratoidea - Bassleroceratidae
Dwightoceras dactyloides Dwight 1884
NYSM 17486