LGS 21 (Paleocene of the United States)

Where: Natchitoches County, Louisiana (31.7° N, 93.4° W: paleocoordinates 35.2° N, 76.3° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Marthaville Formation (Wilcox Group), Thanetian (59.2 - 56.0 Ma)

• formation-level stratigraphic resolution

Environment/lithology: marine; unlithified, concretionary, ferruginous, glauconitic, calcareous siltstone

• Fossils occur in glauconitic calcareous silty mass and in ferruginous concretions.

Size classes: macrofossils, mesofossils

Primary reference: J. O. Barry and R. J. LeBlanc. 1942. Lower Eocene Faunal Units of Lousiana. Geological Bulletin of the state of Louisiana Dept. of Conservation (23)1-208 [J. Sessa/L. Eccles/L. Eccles]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 99725: authorized by Jocelyn Sessa, entered by Laurie Eccles on 19.11.2010

Creative Commons license: CC BY (attribution)

Taxonomic list

Bivalvia
 Ostreida - Ostreidae
"Ostrea thirsae" = Odontogryphaea thirsae
"Ostrea thirsae" = Odontogryphaea thirsae Gabb 1862 oyster
 Arcida - Arcidae
"Arca (Barbatia) cuculloides" = Barbatia (Cucullaearca) cuculloides
"Arca (Barbatia) cuculloides" = Barbatia (Cucullaearca) cuculloides Conrad 1833 clam
Arca (Barbatia) cuculloides ludoviciana
 Carditida - Carditidae
Venericardia (Venericor) densata Conrad 1845 clam
Venericardia (Venericor) densata pendletonensis
 Cardiida - Cardiidae
"Cardium (Cerastoderma) tuomeyi" = Acanthocardia (Schedocardia) tuomeyi
"Cardium (Cerastoderma) tuomeyi" = Acanthocardia (Schedocardia) tuomeyi Aldrich 1886 cockle
Cardium (Cerastoderma) tuomeyi var.
 Cardiida - Tellinidae
Tellina ? sp. Linnaeus 1758 tellin clam
Gastropoda
 Neogastropoda - Raphitomidae
 Neogastropoda - Melongenidae
 Cerithioidea - Turritellidae
"Turritella mortoni" = Kapalmerella mortoni
"Turritella mortoni" = Kapalmerella mortoni Conrad 1830 turret shell
Turritella mortoni postmortoni