M 31 (Paleocene of the United States)

Where: Jackson County, Arkansas (35.5° N, 91.4° W: paleocoordinates 39.1° N, 70.4° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Clayton Formation (Midway Group), Danian (66.0 - 61.6 Ma)

• formation-level stratigraphic resolution

Environment/lithology: marine; lithology not reported

Size class: mesofossils

Primary reference: K. V. Palmer and D. C. Brann. 1965. Catalogue of the Paleocene and Eocene mollusca of the southern and eastern United States. Part 1. Pelecypoda, Amphineura, Peteropoda, Scaphopoda and Cephalopoda. Bulletins of American Paleontology 48:1-471 [M. Kosnik/M. Kosnik/J. Alroy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 91870: authorized by Jocelyn Sessa, entered by Laurie Eccles on 22.10.2009

Creative Commons license: CC BY (attribution)

Taxonomic list

Gastropoda
 Sorbeoconcha - Turritellidae
"Turritella mortoni" = Kapalmerella mortoni
"Turritella mortoni" = Kapalmerella mortoni Conrad 1830 turret shell
Turritella mortoni mediavia
Echinoidea
 Spatangoida - Schizasteridae
Linthia alabamensis Clark and Twitchell 1915 heart urchin