Bluff on southwest side of Missouri River (Cretaceous to of the United States)

Also known as Hydralmosaurus serpentinus type locality

Where: Nebraska (42.7° N, 96.8° W: paleocoordinates 47.1° N, 64.9° W)

• coordinate estimated from map

• small collection-level geographic resolution

When: Sharon Springs Member (Pierre Shale Formation), Early/Lower Campanian to Early/Lower Campanian (83.5 - 70.6 Ma)

• Storrs (1999, p. 5) suggests Sharon Springs Shale Member, Pierre Shale (Campanian), accompanied by a discussion of Welles (1962) provenance of 'Cretaceous No. 3 (i.e. Niobrara Chalk, or Pierre Shale). and description of the matrix: "blue shale with selenite venation,quite unlike Niobrara rocks but identical to matrix associated with known Pierre specimens"

•Carpenter (1999, p. 156) stated "Smoky Hill Chalk member, Niobrara Formation (Santonian?)" without justification.

•The Sharon Springs member in Nebraska has an ammonite zone range of Baculites sp. (smooth)–Baculites mclearni (Early-Middle Campanian) according to Gill et al. (1972).

• bed-level stratigraphic resolution

Environment/lithology: marine; blue shale

Size class: macrofossils

Collected by E. D. Cope in 1876; reposited in the AMNH

Collection methods: surface (in situ)

Primary reference: E. D. Cope. 1877. Report on the geology of the region of the Judith River, Montana, and on vertebrate fossils obtained on or near the Missouri River. Bulletin of the United States Geological and Geographical Survey 3(3):565-597 [M. Carrano/M. Carrano/E. Vlachos]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 116621: authorized by Roger Benson, entered by Roger Benson on 10.09.2011, edited by Philip Mannion

Creative Commons license: CC BY (attribution)

Taxonomic list

 Sauropterygia - Elasmosauridae
Styxosaurus sp. Welles 1943 elasmosaur
AMNH 1495 (holotype)