MGS #35 Sample 6 (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 (Vicksburg Group), Rupelian (33.9 - 28.1 Ma)

• Sample Level 6 1.5m above base of red bluff formation.

•The basal member of the Vicksburg Group, the Red Bluff formation occurs just above the Yazoo Clay.

•The contact between the Yazoo clay and the overlying silty glauconitic Red Bluff formation is abrupt and contains the features of a typical disconformable transgressive contact

• formation-level stratigraphic resolution

Environment/lithology: marine; unlithified, glauconitic, gray, silty claystone and siltstone

• deeper water following transgressive event
• the contact between the Yazoo clay and the Red Bluff formation "includes lenses of glauconite, bored encrusted pebbles and burrows that pipe the Red Blugg into the underlying Yazoo.

•Sparsley fossiliferous blue gray clay

Size class: mesofossils

Preservation: original aragonite, original calcite

Collection methods: bulk, mechanical,

• molluscs only---Samples were dried and washed through 1.00m sieves. Wet sieved with minimal breakage. Random subsamples of the washed shell material were taken and completely picked for all identifiable shells including bivalve beaks and gastropod apices. All bivalve beaks were counted and then divided by two. Each gastropod apex was counted as one individual.

Primary reference: T. A. Hansen, P.H. Kelley, and D.M. Haasl. 2004. Paleoecological patterns in molluscan extinctions and recoveries: comparison of the Cretaceous-Paleogene and Eocene-Oligocene extinctions in North America. Palaeogeography, Palaeoclimatology, Palaeoecology 214:233-242 [A. Miller/K. Bulinski]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 74082: authorized by Arnold Miller, entered by Kate Bulinski on 20.07.2007

Creative Commons license: CC BY (attribution)

Taxonomic list

• molluscs only
unclassified
  -
Bivalvia
 Nuculida - Nuculidae
Nucula vicksburgensis Conrad 1848 nut clam
Brevinucula pseudopunctata Dockery 1982 nut clam
 Nuculanida - Yoldiidae
Yoldia clydoniona Dockery 1982 clam
 Arcida - Arcidae
Scapharca invidiosa Casey 1903 clam
 Pectinida - Pectinoidae
"Eburneopecten subminutus" = Eburneopecten (Eburneopecten) subminutus
"Eburneopecten subminutus" = Eburneopecten (Eburneopecten) subminutus Aldrich 1903 scallop
 Lucinida - Lucinidae
"Myrtaea scopularis" = Myrtea
"Myrtaea scopularis" = Myrtea clam
 Cardiida - Kelliellidae
 Cardiida - Cardiidae
Nemocardium eocenense Meyer 1887 cockle
 Pholadida - Corbulidae
 Poromyida - Spheniopsidae
 Poromyida - Verticordiidae
 Carditida - Astartidae
Astarte triangulata Meyer 1886 clam
Scaphopoda
 Gadilida - Gadilidae
Cadulus sp. Philippi 1844 tusk shell
sp. B
 Dentaliida - Dentaliidae
Dentalium sp. Linnaeus 1758 tusk shell
Gastropoda
 Vanikoroidea - Eulimidae
 Cerithioidea - Turritellidae
 Neogastropoda - Terebridae
 Neogastropoda - Drilliidae
 Neogastropoda - Turridae
Gemmula amica Casey 1903 turrid
 Sorbeoconcha - Naticidae
Natica caseyi moon snail
 Heterostropha - Pyramidellidae
 Heterostropha - Ringiculidae
Ringicula mississippiensis Conrad 1848 snail
 Thecosomata - Limacinidae
Limacina sp. Bosc 1817 snail