Pueblo, lower limestone [Smoky Hill Shale, Niobrara Fm] (Cretaceous of the United States)

Where: Pueblo County, Colorado (38.3° N, 104.6° W: paleocoordinates 41.3° N, 70.7° W)

• coordinate based on nearby landmark

• basin-level geographic resolution

When: Baculites asper ammonoid zone, Smoky Hill Shale Member (Niobrara Formation), Middle Coniacian (89.3 - 85.8 Ma)

• STRATIGRAPHIC RELATIONS: From the Smoky Hill Shale Mbr of the Niobrara Fm, which regionally overlies the First Hays Limestone and the Carlisle Shale . AGE: Middle Coniacian, on the basis of inoceramid and ammonite biostratigraphy. STRATIGRAPHIC POSITION: List representative of the the lower limestone 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 87851: 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 - Diplomoceratidae
 Ammonitida - Anisoceratidae
"Phlycticrioceras oregonense" = Phlycticrioceras trinodosus
"Phlycticrioceras oregonense" = Phlycticrioceras trinodosus Geinitz 1850 ammonite
 Ammonitida - Baculitidae
Pseudobaculites sp. Cobban 1952 ammonite
Baculites codyensis Reeside 1927 ammonite
Baculites asper Morton 1830 ammonite
Bivalvia
 Myalinida - Inoceramidae
"Inoceramus (Magadiceramus) subquadratus" = Magadiceramus subquadratus, Inoceramus (Volviceramus) grandis
"Inoceramus (Magadiceramus) subquadratus" = Magadiceramus subquadratus Schlüter 1887 clam