MGS #40 (Oligocene of the United States)

Where: Wayne County, Mississippi (31.7° N, 88.7° W: paleocoordinates 31.9° N, 82.2° W)

• coordinate based on political unit

• outcrop-level geographic resolution

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

• The Red Bluff Formation as exposed is Clarke and Wayne counties, Mississippi, consists of fossiliferous, dark clay,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 during in shallow marine shelf, prodelta, and marginal delta bay enviroments. Along the Chickasawhay River in Wayne County, the lower portion of the Red Bluff Formation is very fossiliferous. Well-preserved fossils in this basal zone occur in abundance in narrow, glauconitic, sand lenses within the clay. Irregular ironstone concretions occur along fosiliferous zones in the lower Red Bluff Formation and show up on electric logs as one or two "kicks" on the resistivity curve at the base of the formation.

• formation-level stratigraphic resolution

Environment/lithology: offshore; poorly lithified, 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 5787: authorized by Linda Ivany, entered by Sarah DeLong on 02.12.1999, edited by Laurie Eccles

Creative Commons license: CC BY (attribution)

Taxonomic list

• Taxonomic list is recorded in catagories due to the fact that the author of this collection recorded all abundances of a species more than 100 as an "A",all other species with lesser numbers were documented as that number. This list has been catigorized as 1-9 valves found is an "R" as in rare, 10-99 valves found "C" common, and 100+ valves found is "A" for abundant, like the author had it.

•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
 Epitonioidea - Epitoniidae
Confusiscala durhami n. sp.2 wentletrap
 Sorbeoconcha - Cassidae
"Mambrinia brevidentata" = Galeodea2, Sconsia prelintea n. sp.2
"Mambrinia brevidentata" = Galeodea2 snail
Sconsia prelintea n. sp.2 snail
 Sorbeoconcha - Ranellidae
Sassia conradiana2 triton shell
 Sorbeoconcha - Eocypraeidae
Sulcocypraea healeyi2 Aldrich 1923 snail
 Sorbeoconcha - Ficidae
Ficus mississippiensis2 Conrad 1848 fig shell
 Neogastropoda - Costellariidae
Vexillum lintoidea2 ribbed mitre
 Neogastropoda - Mitridae
"Mitra (Fusimitra) conquisita" = Fusimitra conquisita1, Mitra conquista2
"Mitra (Fusimitra) conquisita" = Fusimitra conquisita1 Conrad 1848 mitre shell
Mitra conquista2 mitre shell
 Neogastropoda - Fasciolariidae
Latirus aldrichi n. sp.2 snail
 Neogastropoda - Buccinidae
Metula fastidiosa2 true whelk
 Neogastropoda - Volutidae
 Neogastropoda - Muricidae
 Neogastropoda - Clavatulidae
 Neogastropoda - Turridae
Bivalvia
 Nuculanida - Yoldiidae
Yoldia clydoniona n. sp. Dockery 1982 clam
C category
 Nuculida - Nuculidae
Nucula vicksburgensis Conrad 1848 nut clam
R category
Brevinucula pseudopunctata Dockery 1982 nut clam
C category
 Poromyida - Verticordiidae
Verticordia dalliana clam
R category
Haliris quadrangularis clam
R category
 Pholadida - Corbulidae
Corbula rufaripa n. sp. clam
100+ valves collected
Corbula engonata Conrad 1848 clam
C category
 Cardiida - Chamidae
"Chama mississippiensis" = Chama (Psilopus) mississippiensis
"Chama mississippiensis" = Chama (Psilopus) mississippiensis Conrad 1848 jewel box
C category
 Cardiida - Veneridae
Pitar aldrichi n. sp. venus clam
R category
 Cardiida - Semelidae
Abra pectorosa abra
R category
 Cardiida - Cardiidae
Nemocardium eocenense Meyer 1887 cockle
C category
Agnocardia glebosum Conrad 1848 cockle
R category
 Lucinida - Lucinidae
Myrtea scopularis Casey 1903 clam
C category
 Carditida - Carditidae
"Venericardia carsonensis" = Venericardia (Rotundicardia) carsonensis
"Venericardia carsonensis" = Venericardia (Rotundicardia) carsonensis Dall 1903 clam
R category
 Carditida - Astartidae
Astarte triangulata Meyer 1886 clam
100+ valves collected
 Mytilida - Mytilidae
Septifer probolus n. sp. mussel
R category [entered as Septifer probulus]
 Pectinida - Pectinoidae
"Eburneopecten subminutus" = Eburneopecten (Eburneopecten) subminutus, "Pecten perplanus" = Pecten (Pecten) perplanus, Spondylus dumosus
"Eburneopecten subminutus" = Eburneopecten (Eburneopecten) subminutus Aldrich 1903 scallop
C category
"Pecten perplanus" = Pecten (Pecten) perplanus Morton 1833 scallop
R category
Spondylus dumosus Morton 1834 scallop
C category
 Pectinida - Plicatulidae
Plicatula variplicata n. sp. Dockery 1982 scallop
R category
 Pectinida - Dimyidae
Dimya rufaripa Vokes 1979 scallop
100+ valves collected
 Ostreida - Ostreidae
Lopha vicksburgensis Conrad 1848 oyster
C category
 Arcida - Arcidae
Barbatia paradiagona n. sp. Dockery 1982 clam
R category
Scapharca invidiosa Casey 1903 clam
100+ valves collected
 Arcida - Glycymerididae
Glycymeris intercostata Gabb 1860 clam
C category
Anthozoa
 Scleractinia - Dendrophylliidae
Balanophyllia (Balanophyllia) elongata1 Vaughan 1900 stony coral