Where: Fergus County, Montana (47.0° N, 109.0° W: paleocoordinates 40.5° N, 50.6° W)
• coordinate based on nearby landmark
• outcrop-level geographic resolution
When: Gowericeras subitum ammonoid zone, Rierdon Formation (Ellis Group), Early/Lower Callovian (164.7 - 161.2 Ma)
• From lower 15 feet of Rierdon Formation
• group of beds-level stratigraphic resolution
Environment/lithology: marine; lithified lithology not reported
Size class: macrofossils
Preservation: mold/impression
Reposited in the USNM
Primary reference: B. Kummel. 1954. Jurassic nautiloids from western North America. Journal of Paleontology 28:320-324 [M. Clapham/M. Clapham/M. Clapham]more details
Purpose of describing collection: taxonomic analysis
PaleoDB collection 180713: authorized by Matthew Clapham, entered by Matthew Clapham on 29.07.2016
Creative Commons license: CC BY (attribution)
Taxonomic list
Cephalopoda | |
Eutrephoceras montanensis n. sp.
Eutrephoceras montanensis n. sp. Kummel 1954 nautiloid |