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)
Taxonomic list
Echinoidea | |
Micraster americanus Stephenson 1941 heart urchin | |
Cephalopoda | |
"Nostoceras (Nostoceras) hyatti" = Nostoceras hyatti, Nostoceras (Nostoceras) approximans, "Didymoceras navarroense" = Cirroceras conradi
"Nostoceras (Nostoceras) hyatti" = Nostoceras hyatti Stephenson 1941 ammonite
Nostoceras (Nostoceras) approximans Conrad 1855 ammonite
"Didymoceras navarroense" = Cirroceras conradi Morton 1841 ammonite | |
Baculites ovatus Say 1820 ammonite | |
"Hoploscaphites pumilis" = Hoploscaphites pumilus
"Hoploscaphites pumilis" = Hoploscaphites pumilus Stephenson 1941 ammonite |