MGS #46 (Oligocene of the United States)

Where: Clarke County, Mississippi (31.8° N, 88.8° W: paleocoordinates 32.1° N, 82.3° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Red Bluff Formation, Rupelian (33.9 - 28.1 Ma)

• The Red Bluff Formation as exposed in Clarke and Wayne counties,Mississippi, consists of fossiliferous, dark gray, silty clay with zones of ironstone concretions in the lower part. These sediments disconformably overlie the blue-gray, blocky, marine clay of the Shubuta clay member of the yazoo Formation and were deposited in shallow marine shelf, prodelta, and marginal delta bay enviroments.

• formation-level stratigraphic resolution

Environment/lithology: offshore; gray, silty, sandy siltstone and ironstone

Size class: mesofossils

Preservation: original aragonite, original calcite

Collection methods: bulk, mechanical,

• Bivalves only

Primary reference: D. T. Dockery. 1982. Lower Oligocene Bivalvia of the Vicksburg Group in Mississippi. Mississippi Department of Natural Resources Bureau of Geology 123:1-261 [L. Ivany/S. DeLong/M. Uhen]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 5788: authorized by Linda Ivany, entered by Sarah DeLong on 02.12.1999, edited by Laurie Eccles

Creative Commons license: CC BY (attribution)

Taxonomic list

• List is done in catagory form. 1-9 valves collected of smae species = "R" for rare. 10-99 valves collected = "C" for common. 100+ valves collected = "A" for abundant. Categories are listed in the comments field, absolute abundances are given in the abundance field.

•Since taxa with greater than 99 specimens were not counted with absolute abundances, these were reported with category "A" for abundant.

Gastropoda
 Neogastropoda - Mitridae
"Mitra (Fusimitra) conquisita" = Fusimitra conquisita1, Mitra conquista2
"Mitra (Fusimitra) conquisita" = Fusimitra conquisita1 Conrad 1848 mitre shell
Mitra conquista2 mitre shell
 Neogastropoda - Volutidae
 Sorbeoconcha - Ranellidae
Sassia conradiana1 triton shell
Bivalvia
 Arcida - Arcidae
Scapharca invidiosa Casey 1903 clam
R category
 Arcida - Glycymerididae
Glycymeris intercostata Gabb 1860 clam
R category
 Pectinida - Pectinoidae
"Pecten perplanus" = Pecten (Pecten) perplanus
"Pecten perplanus" = Pecten (Pecten) perplanus Morton 1833 scallop
C category
 Lucinida - Lucinidae
Myrtea scopularis Casey 1903 clam
R category
 Pholadida - Corbulidae
Corbula engonata Conrad 1848 clam
R category
Tiza alta clam
100+ valves collected
 Cardiida - Veneridae
Pitar aldrichi n. sp. venus clam
C category
 Cardiida - Ungulinidae
Timothynus turgida Conrad 1848 clam
R category
 Cardiida - Cardiidae
Nemocardium eocenense Meyer 1887 cockle
R category
Agnocardia glebosum Conrad 1848 cockle
R category
 Carditida - Astartidae
Astarte triangulata Meyer 1886 clam
R category
 Carditida - Carditidae
"Venericardia carsonensis" = Venericardia (Rotundicardia) carsonensis
"Venericardia carsonensis" = Venericardia (Rotundicardia) carsonensis Dall 1903 clam
R category