USGS 13504 - Tamaulipas, Mexico (Jackson Formation) (Eocene of Mexico)

Also known as USGS 13504

Where: Tamaulipas, Mexico (26.3° N, 98.8° W: paleocoordinates 27.4° N, 91.5° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Middle Member (Jackson Formation), Late/Upper Eocene (37.2 - 33.9 Ma)

• The Jackson Group of Mexico and the Gulf Coastal Plain is here considered as a formation. The Jackson Formation can be subdivided into three members, the basal "Roma Sandstone" and middle and upper members (no lithostratigraphic name). No comments are made on relations to Gulf Coastal Plain units, but the enterer considers that the Jackson Formation of this collection is equivalent in age (late Eocene) as the Jackson Group (Gulf Coastal Plain). Collection is from a 10-15 ft lens of fine-grained sandstone or limestone, overlain and underlain by gypsiferous clays and sandy clays.

• bed-level stratigraphic resolution

Environment/lithology: coastal; fine-grained, calcareous sandstone and fine-grained, sandy limestone

• Siliciclastic. Enterer considers the fauna to be an inner shelf assemblage. No paleoenvironmental data reported.
• Fine-grained calcareous sandstone or sandy limestone.

Size class: macrofossils

Reposited in the USNM

Collection methods: quarrying,

• Collections reposited in USGS and USNM collections.

Primary reference: J. Gardner. 1945. Mollusca of the Tertiary formations of Northeastern Mexico. Geological Society of American Memoir 11 [M. Kosnik/M. Kosnik/M. Kosnik]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 43057: authorized by Austin Hendy, entered by Austin Hendy on 09.08.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Exhaustive for mollusca.
 Pholadida - Corbulidae
 Nuculida - Nuculidae
"Nucula spheniopsis" = Nucula (Nucula) sphenopsis
"Nucula spheniopsis" = Nucula (Nucula) sphenopsis Conrad 1865 nut clam
 Cephalaspidea - Retusidae
 Cephalaspidea - Cylichnidae
Acteocina melinoides barrel-bubble
 Neogastropoda - Olividae
"Ancillopsis ? subglobosa" = Ancillaria (Ancillopsis)
"Ancillopsis ? subglobosa" = Ancillaria (Ancillopsis) olive snail
 Neogastropoda - Buccinidae
Pseudoliva ? vetusta, "Buccitriton ? hilli" = Phos (Buccitriton)
Pseudoliva ? vetusta Conrad 1865 true whelk
"Buccitriton ? hilli" = Phos (Buccitriton) true whelk
Subspecies: Buccitriton hilli jacksonensis
 Neogastropoda - Mitridae
"Mitra (Fusimitra) millingtoni" = Fusimitra
"Mitra (Fusimitra) millingtoni" = Fusimitra mitre shell
 Neogastropoda - Volutidae
"Volutospina symmetrica" = Athleta (Volutospina)
"Volutospina symmetrica" = Athleta (Volutospina) volute
 Neogastropoda - Conidae
"Conus (Leptoconus) tortilus" = Conus sauridens
"Conus (Leptoconus) tortilus" = Conus sauridens Conrad 1833 cone shell
 Stromboidea - Rostellariidae
Calyptraphorus velatus Conrad 1833 snail
 Sorbeoconcha - Turritellidae
"Turritella arenicola" = Kapalmerella arenicola
"Turritella arenicola" = Kapalmerella arenicola Conrad 1865 turret shell
 Architectonicoidea - Architectonicidae
"Architectonica alveata" = Architectonica (Stellaxis) alveatum Conrad 1833 sundial
 Dentaliida - Dentaliidae
"Dentalium (Antalis) ? mississippiense" = Antalis
"Dentalium (Antalis) ? mississippiense" = Antalis tusk shell
 Gadilida - Gadilidae