Where: Butte County, South Dakota (44.7° N, 103.8° W: paleocoordinates 44.1° N, 63.9° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Sciponoceras gracile ammonoid zone, Greenhorn Formation, Late/Upper Cenomanian (99.6 - 93.5 Ma)

• bed-level stratigraphic resolution

Environment/lithology: marine; lithified, shelly/skeletal limestone

Size class: macrofossils

Collected by J.B. Reeside, H.R. Christner, W.A. Cobban in 1950; reposited in the USNM

Primary reference: W. A. Cobban. 1988. Tarrantoceras Stephenson and related ammonoid genera from Cenomanian (Upper Cretaceous) rocks in Texas and the western interior of the United States. United States Geological Survey Professional Paper 1473:1-30 [M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 177086: authorized by Matthew Clapham, entered by Matthew Clapham on 19.03.2016

Creative Commons license: CC BY (attribution)