Raton Basin, uppermost upper shale [Smoky Hill Shale, Niobrara Fm] (Cretaceous of the United States)

Where: New Mexico (36.4° N, 104.6° W: paleocoordinates 40.6° N, 72.1° W)

• coordinate based on nearby landmark

• basin-level geographic resolution

When: Smoky Hill Shale Member (Niobrara Formation), Santonian (86.3 - 83.6 Ma)

• STRATIGRAPHIC RELATIONS: From the Lower Shale of the Smokey Hill Shale, Niobrara Fm, which regionally overlies the Carlisle Shale . AGE: Early Campanian, on the basis of inoceramid and ammonite biostratigraphy. STRATIGRAPHIC POSITION: List representative of the uppermost part of the upper shale unit of the Smoky Hill Shale.

• group of beds-level stratigraphic resolution

Environment/lithology: deep subtidal shelf; lithified shale

• ENVIRONMENT: Offshore marine carbonate environment.
• SPECIFIC LITHOLOGY: Shale. LITHIFICATION: Lithified, on the basis of facies description and figured specimens.

Size class: macrofossils

Preservation: cast, mold/impression

Reposited in the UNSM

Collection methods: surface (in situ), ,

• COLLECTORS: Scott, Cobban, Merewether, and Buckhorn (1984). REPOSITORY: USNM.

Primary reference: G. R. Scott, W. A. Cobban, and E. A. Merewether. 1986. Stratigraphy of the Upper Cretaceous Niobrara Formation in the Raton basin, New Mexico. New Mexico Bureau of Mines and Mineral Resources Bulletin 115:1-34 [A. Hendy/A. Hendy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 87850: authorized by Austin Hendy, entered by Austin Hendy on 26.03.2009

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Exhaustive for ammonoids, nautiloids, and bivalves. NOMENCLATURE: Not an authoritative publication, but with modern nomenclature, and identifications to species-level.
Cephalopoda
 Ammonitida - Scaphitidae
Scaphites hippocrepis DeKay 1828 ammonite
 Ammonitida - Baculitidae
Baculites haresi Reeside 1927 ammonite
 Ammonitida - Placenticeratidae
Placenticeras sp. Meek 1876 ammonite
 Nautilida - Nautilidae
Eutrephoceras sp. Hyatt 1894 nautiloid
Bivalvia
 Myalinida - Inoceramidae
"Inoceramus (Platyceramus) cycloides" = Platyceramus cycloides Wegner 1905 clam