Where: Howard County, Arkansas (33.8° N, 93.9° W: paleocoordinates 37.9° N, 65.6° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Nostoceras hyatti ammonoid zone, Saratoga Chalk Formation (Navarro Group), Late/Upper Campanian (83.5 - 70.6 Ma)

• STRATIGRAPHIC RELATIONS: From the Saratoga Chalk, which regionally overlies the Marlbrook Marl, and is overlain by the Nacatoch Sand Fm, all of the Navarro Gp. AGE: Late Campanian on the basis of ammonite biostratigraphy; Nostoceras hyatti zone. STRATIGRAPHIC POSITION: From unknown position within formation of 6-16 m in thickness.

• bed-level stratigraphic resolution

Environment/lithology: lithified lime mudstone and lithified, calcareous sandstone

Size class: macrofossils

Preservation: cast, mold/impression

Collected by Stephenson in 1916; reposited in the USNM

Collection methods: surface (in situ),

• COLLECTOR: L.W. Stephenson. REPOSITORY: USNM, Washington DC.

Primary reference: C. W. Cooke. 1953. American Upper Cretaceous Echinoidea. United States Geological Survey Professional Paper 254-A:1-44 [W. Kiessling/U. Merkel/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 83037: authorized by Austin Hendy, entered by Austin Hendy on 06.08.2008, edited by Matthew Clapham

Creative Commons license: CC BY (attribution)