Also known as Beekmantown Gr., Locality 22, not Kirby ledge

Where: Clinton County, New York (44.8° N, 73.5° W: paleocoordinates 30.0° S, 61.0° W)

• coordinate based on nearby landmark

• small collection-level geographic resolution

When: Fort Cassin Formation (Beekmantown Group), Cassinian (482.3 - 470.0 Ma)

• Kröger and Landing, 2009:

•Problems exist with the fossils that Whitfield (1889) stated that H. M. Seely

•collected at Kirby ledge north of Beekmantown (Fig. 1, locality KL).

•Landing and Westrop (2006, p. 958, 959) found lower Blackhillsian Stage

•trilobites dominated by Isoteloides in the Sciota Member at Kirby ledge—a

•much younger assemblage than the Stairsian Stage forms [Bathyurus conicus

•Billings, 1859a, and Paraplethopeltis seelyi (Whitfield, 1886)] reported by

•Whitfield (1886). Indeed, Stairsian strata seem to be absent in the

•Beekmantown area (Landing and Westrop, 2006). EL did not find

•cephalopods at Kirby ledge, though Whitfield (1886) described Cyrtoceras

•beekmanensis Whitfield, 1886, C. kirbyi Whitfield, 1886, and Seelyoceras raei

•(Whitfield, 1886) in ‘‘the dark blue band of limestone below the lower

•Ophileta bed.’’ This limestone is not described at Kirby ledge, where a 60 cm

•‘‘siliceous limestone’’ below the lower Ophileta bed is ‘‘destitute of fossils’’

•(Whitfield, 1886, p. 42). Seely may have collected fossils elsewhere for

•Whitfield’s (1886) report (Landing and Westrop, 2006, p. 963). Seely (1910,

•p. 280) noted the specimens he gave toWhitfield were collected in 1884–1888

•from ‘‘boulders’’ in a creek and from ‘‘ridges further up’’ at East

•Beekmantown, and apparently not at Kirby ledge north of Beekmantown.

•The only named cephalopods that can be confidently referred to the

•Fort Cassin Formation near Beekmantown were described by Ruedemann

•(1906) from NYSM locality 3327. These include Cyrtoceras? priscum

•Ruedemann, 1906 (which we regard as a gastropod); Endoceras?

•champlainense Ruedemann, 1906; and Protocycloceras lamarcki (Billings,

•1859). C. A. Hartnagel collected the material in 1903, and Ruedemann

•(1906) reported them from ‘‘Spellman Ledge’’—a locality often cited in the

•older literature but never located on a map. Ruedemann’s (1906)

•specimens occur in a burrow-churned, brown-weathering, dolomitic

•sandstone—a lithology identical to the Ward Member south of the

•Spellman Road–Delaware and Hudson Railroad crossing at the old

•Beekmantown station (Landing and Westrop, 2006, fig. 1.2).

• formation-level stratigraphic resolution

Environment/lithology: shallow subtidal; blue, calcareous lime mudstone and lithified, shelly/skeletal grainstone

Size class: macrofossils

Preservation: original aragonite, replaced with calcite

Primary reference: E. O. Ulrich, A. F. Foerste, A. K. Miller and W. M. Furnish. 1944. Ozarkian and Canadian cephalopods, longicones and summary. Geological Society of America Special Paper 58:1-226 [P. Wagner/P. Wagner/B. Kröger]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 101293: authorized by Björn Kröger, entered by Björn Kröger on 20.12.2010

Creative Commons license: CC BY (attribution)