Where: Arkansas (35.7° N, 91.6° W: paleocoordinates 13.9° S, 34.7° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Goniatites granosus ammonoid zone, Ruddell Formation, Brigantian (336.0 - 330.9 Ma)

• Ruddell shale, middle part; zone of phosphatic nodules about 40 ft thick.

• bed-level stratigraphic resolution

Environment/lithology: marine; lithified, nodular, phosphatic shale

Size class: macrofossils

Collected by M. Gordon, R.A. Lewandowski in 1953; 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 157844: authorized by Matthew Clapham, entered by Matthew Clapham on 06.07.2014

Creative Commons license: CC BY (attribution)