USGS D2119: Late Maastrichtian, Wyoming
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
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Cephalopoda
- Ammonitida
- Baculitidae
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Baculites grandis
Hall and Meek 1855
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Cephalopoda
- Ammonitida
- Scaphitidae
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Hoploscaphites sp.
Nowak 1911
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= Hoploscaphites sargklofak
Landman et al. 2015
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Landman et al. 2015 | |||||||||
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Bivalvia
- Nuculanida
- Nuculanidae
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Nuculana bisulcata
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unclassified
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Bryozoa indet.
Ehrenberg 1831
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| membraniporoid bryozoan | ||||||||||
| see common names | ||||||||||
Geography
| Country: | United States | State/province: | Wyoming | County: | Niobrara |
| Coordinates: | 43.3° North, 104.3° West (view map) | ||||
| Paleocoordinates: | 49.7° North, 79.1° West | ||||
| Basis of coordinate: | estimated from map | ||||
| Geographic resolution: | small collection |
Time
| Period: | Cretaceous | Epoch: | Late Cretaceous |
| Stage: | Maastrichtian | 10 m.y. bin: | Cretaceous 8 | *Epoch: | Senonian |
| Key time interval: | Late Maastrichtian | Ammonoid zone: | Baculites grandis |
| Age range of interval: | 72.1 - 66 m.y. ago | ||
| * legacy (obsolete) database fields | |||
Stratigraphy
| Formation: | Pierre Shale | Member: | upper unnamed shale | ||
| Regional section: | Formation | Regional bed: | 363 - 418 ft | ||
| Regional order: | top to bottom | ||||
| Stratigraphic resolution: | bed | ||||
| Stratigraphy comments: Pierre shale, from limestone concretions 363 - 418' below top. Was bed 98 | |||||
Lithology and environment
| Primary lithology: | gray lithified silty "shale" | ||
| Secondary lithology: | "carbonate" | ||
| Environment: | offshore | Tectonic setting: | cratonic basin |
| Geology comments: "Shale. dark gray where fresh, weathers gray; contains laminae of lighter gray soft siltstone and fine-gr. ss. a few small brown-weathering concretions, commonly very fossiliferous, are scattered throughout the unit." | |||
Taphonomy
| Modes of preservation: | body |
| Size of fossils: | macrofossils |
Collection methods and comments
| Collection methods: | mechanical,field collection |
| Reason for describing collection: | biostratigraphic analysis |
| Museum repositories: | USGS |
| Collection method comments: "[collected] from concretions throughout unit" | |
| Taxonomic list comments:"The fossils are ordinarily well-preserved. Most of the cephalopod shells and the inner nacreous layer of Inoceramus are aragonitic, especially specimens from above the Red Bird Silty Member. Shell material and specimens from the Red Bird member and the upper 50' of the underlying Mitten Member is partially transformed to calcite...Ammonites...of the [mid-upper third] of the Mitten Member are...entirely aragonite whereas shell material [of underlying material] is completely transformed to calcite." | |
Metadata
| Also known as: | Pierre Shale (USGS D2119) | ||
| Database number: | 1581 | ||
| Authorizer: | J. Alroy, P. Wagner | Enterer: | M. Sommers, P. Wagner |
| Modifier: | P. Wagner | Research group: | marine invertebrate |
| Created: | 1999-05-17 16:22:55 | Last modified: | 2024-03-17 14:34:18 |
| Access level: | the public | Released: | 1999-05-17 16:22:55 |
| Creative Commons license: | CC BY | ||
Reference information
Primary reference:
| 45. | J. R. Gill, W. A. Cobban, and P. M. Kier. 1966. The Red Bird Section of the Upper Cretaceous Pierre Shale in Wyoming. United States Geological Survey Professional Paper 393-A:1-73 [J. Alroy/M. Sommers/A. Clement] |
Secondary references:
| 87912 | N. H. Landman, W. J. Kennedy, and N. L. Larson. 2015. A new species of scaphitid ammonite from the Lower Maastrichtian of the Western Interior of North America, with Close Affinities to Hoploscaphites constrictus Sowerby, 1817. American Museum Novitates 3833:1-40 [P. Wagner/P. Wagner] |