Wallace Ranch: Early/Lower Campanian - Middle Campanian, South Dakota
collected by Univ. Nebraska 1966

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Reptilia - Hesperornithiformes
Hesperornis cf. regalis Marsh 1872
1 individual
"slightly smaller...but agrees with that species in most other respects"
Reptilia - Plesiosauria - Polycotylidae
Polycotylidae indet. Williston 1908
O'Keefe 2008 1 individual
UNSM 55810 (juvenile skeleton; reported as UNSM 44810 by Adams [1997])
Dolichorhynchops osborni Williston 1902
O'Keefe 2008 1 individual
UNSM 50133 (skull; reported as USNM 50144 by Adams [1997])
Trinacromerum bonneri Adams 1997
Adams 1997 1 individual
KUMNH 40001 (holotype: skull, lower jaws, first three cervical vertebrae (articulated), pubes and ischia, left humerus and femur, vertebrae and ribs);
    = Martinectes bonneri Adams 1997
Clark et al. 2024
see common names

Geography
Country:United States State/province:South Dakota County:Fall River
Coordinates: 43.0° North, 103.3° West (view map)
Paleocoordinates:48.9° North, 71.5° West
Basis of coordinate:stated in text
Geographic resolution:local area
Time
Period:Cretaceous Epoch:Late/Upper Cretaceous
Stage:Campanian 10 m.y. bin:Cretaceous 7
Key time interval:Early/Lower Campanian - Middle Campanian Ammonoid zone: Baculites sp. (smooth) - Baculites perplexus
Age range of interval:83.50000 - 70.60000 m.y. ago
Stratigraphy
Geological group:Montana Formation:Pierre Shale Member:Sharon Springs
Stratigraphic resolution:formation
Stratigraphy comments: 10 ft below Ardmore Bentonite
The Sharon Springs Member spans Baculites sp. (smooth) - Baculites perplexus in South Dakota
Lithology and environment
Primary lithology: not reported
Environment:marine indet.
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Preservation of anatomical detail:good
Associated major elements:all
Fragmentation:occasional
Spatial resolution:parautochthonous
Collection methods and comments
Collection methods:field collection
Reason for describing collection:taxonomic analysis
Museum repositories:UNSM
Collectors:Univ. Nebraska Collection dates:1966
Metadata
Also known as:T. bonneri paratype
Database number:77316
Authorizer:M. Carrano, E. Vlachos, R. Benson Enterer:M. Carrano, F. Aspromonte, R. Benson
Modifier:P. Wagner Research group:vertebrate
Created:2008-01-08 15:10:55 Last modified:2021-02-12 17:43:12
Access level:the public Released:2008-01-08 15:10:55
Creative Commons license:CC BY
Reference information

Primary reference:

36973.ETE L. D. Martin and J. T. Tate, Jr. 1967. A Hesperornis from the Pierre Shale. Proceedings of the 79th Annual Meeting, Nebraska Academy of Sciences 40 [M. Carrano/M. Carrano]

Secondary references:

26171ETE D. A. Adams. 1997. Trinacromerum bonneri, new species, last and fastest pliosaur of the Western Interior Seaway. Texas Journal of Science 49(3):179-198 [M. Carrano/M. Carrano]
87231 R. O. Clark, F. R. O'Keefe, and S. E. Slack. 2024. A new genus of small polycotylid plesiosaur from the Upper Cretaceous of the Western Interior Seaway and a clarification of the genus Dolichorhynchops. Cretaceous Research 157:105812:1-35 [E. Vlachos/F. Aspromonte/P. Mannion]
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]
33004 F. R. O'Keefe. 2008. Cranial anatomy and taxonomy of Dolichorhynchops bonneri new combination, a polycotylid (Sauropteryga: Plesiosauria) from the Pierre Shale of Wyoming and South Dakota. Journal of Vertebrate Paleontology 28(3):664-676 [M. Carrano/H. Street]