Where: Carter County, Montana (45.1° N, 104.5° W: paleocoordinates 44.6° N, 64.3° W)
• coordinate stated in text
• outcrop-level geographic resolution
When: Dunveganoceras pondi ammonoid zone, Belle Fourche Formation, Late/Upper Cenomanian (99.6 - 93.5 Ma)
• Near bentonite G of Knechtel and Patterson (1962)
• group of beds-level stratigraphic resolution
Environment/lithology: marine; lithified, concretionary, calcareous siliciclastic sediments
Size class: macrofossils
Preservation: concretion
Collected by W.A. Cobban in 1964; reposited in the USNM
Primary reference: W. J. Kennedy and W. A. Cobban. 1990. Cenomanian micromorphic ammonites from the western interior of the USA. Palaeontology 33:379-422 [M. Clapham/M. Clapham]more details
Purpose of describing collection: taxonomic analysis
PaleoDB collection 175423: authorized by Matthew Clapham, entered by Matthew Clapham on 11.12.2015
Creative Commons license: CC BY (attribution)
Taxonomic list
Cephalopoda | |
Hamites cimarronensis Kauffman and Powell 1977 ammonite | |
Idiohamites bispinosus Kennedy and Cobban 1990 ammonite | |
"Borissiakoceras sp." = Borissjakoceras
"Borissiakoceras sp." = Borissjakoceras Arkhangel'skii 1916 ammonite | |
Tarrantoceras sp. Stephenson 1955 ammonite
Tarrantoceras cuspidum Stephenson 1953 ammonite
Dunveganoceras pondi Haas 1949 ammonite | |
Moremanoceras costatum Cobban et al. 1989 ammonite |