Bluff on southwest side of Missouri River: Early/Lower Campanian - Middle Campanian, Nebraska
collected by E. D. Cope 1876

List of taxa
Where & when
Taphonomy & methods
Metadata & references
Taxonomic list
Reptilia - Sauropterygia - Elasmosauridae
Hydralmosaurus serpentinus n. gen., n. sp. (Cope 1877)
1 individual
AMNH 1495 (holotype)
    = Styxosaurus sp. Welles 1943
Otero 2016
see common names

Country:United States State/province:Nebraska
Coordinates: 42.7° North, 96.8° West (view map)
Paleocoordinates:47.1° North, 64.9° West
Basis of coordinate:estimated from map
Geographic resolution:small collection
Period:Cretaceous Epoch:Late/Upper Cretaceous
Stage:Campanian 10 m.y. bin:Cretaceous 7
Key time interval:Early/Lower Campanian - Middle Campanian
Age range of interval:83.50000 - 70.60000 m.y. ago
Geological group:Montana Formation:Pierre Shale Member:Sharon Springs
Stratigraphic resolution:bed
Stratigraphy comments: 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).
Lithology and environment
Primary lithology:blue "shale"
Includes fossils?Y
Environment:marine indet.
Modes of preservation:body
Size of fossils:macrofossils
Temporal resolution:snapshot
Collection methods and comments
Collection methods:surface (in situ)
Reason for describing collection:taxonomic analysis
Museum repositories:AMNH
Collectors:E. D. Cope Collection dates:1876
Also known as:Hydralmosaurus serpentinus type locality
Database number:116621
Authorizer:R. Benson, P. Mannion Enterer:R. Benson, P. Mannion
Modifier:P. Mannion Research group:vertebrate
Created:2011-09-10 00:01:24 Last modified:2018-06-14 10:05:45
Access level:the public Released:2011-09-10 00:01:24
Creative Commons license:CC BY
Reference information

Primary reference:

17576.ETE 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]

Secondary references:

26172ETE K. Carpenter. 1999. Revision of North American elasmosaurs from the Cretaceous of the Western Interior. Paludicola 2(2):148-173 [M. Carrano/M. Carrano]
48141 J. R. Gill, W. A. Cobban, and L. G. Schultz. 1972. Stratigraphy and Composition of the Sharon Springs Member of the Pierre Shale in Western Kansas. Geological SUrvey Professional Paper 728:1-50 [R. Benson/R. Benson]
59502 R. A. Otero. 2016. Taxonomic reassessment of Hydralmosaurus as Styxosaurus: new insights on the elasmosaurid neck evolution throughout the Cretaceous. PeerJ 4:e1777:1-60 [C. Boyd/C. Boyd/P. Mannion]
38181 G. W. Storrs. 1999. An examination of Plesiosauria (Diapsida: Sauropterygia) from the Niobrara Chalk (Upper Cretaceous) of Central North America. Paleontological Contributions of the University of Kansas 11:1-15 [R. Benson/R. Benson]