USGS 15058, Pleasant Grove (Carboniferous of the United States)

Where: Arkansas (35.8° N, 91.9° W: paleocoordinates 11.2° S, 31.9° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Eumorphoceras bisulcatum ammonoid zone, Pitkin Formation, Arnsbergian (327.0 - 323.7 Ma)

• Pitkin limestone, upper shale member.

• group of beds-level stratigraphic resolution

Environment/lithology: marine; lithified shale

Size class: macrofossils

Collected by M. Gordon, R. Kopf in 1954; reposited in the USNM

Primary reference: M. Gordon. 1964. Carboniferous Cephalopods of Arkansas. United States Geological Survey Professional Paper 460:1-322 [J. Alroy/C. Simpson/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 157941: authorized by Matthew Clapham, entered by Matthew Clapham on 11.07.2014

Creative Commons license: CC BY (attribution)

Taxonomic list

Cephalopoda
 Pseudorthocerida - Pseudorthoceratidae
 Pseudorthocerida - Spyroceratidae
 Nautilida - Scyphoceratidae
Mariceras "sp. B" Ruzhentsev and Shimanskiy 1954 nautiloid
 Goniatitida - Glaphyritidae
"Cravenoceras involutum" = Stenoglaphyrites involutus
"Cravenoceras involutum" = Stenoglaphyrites involutus Gordon 1964 ammonite
 Actinocerida - Carbactinoceratidae
 Orthocerida - Orthoceratidae