Where: Arkansas (36.0° N, 92.7° W: paleocoordinates 13.2° S, 35.4° 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, weathered shale 15-22.5 feet above top of Boone Formation

• bed-level stratigraphic resolution

Environment/lithology: marine; lithified shale

Size class: macrofossils

Collected by J.C. Maher in 1950; 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

PaleoDB collection 157813: authorized by Matthew Clapham, entered by Matthew Clapham on 04.07.2014

Creative Commons license: CC BY (attribution)