USGS 13459, near Loma Comales (Paleocene of Mexico)

Where: Nuevo Leon, Mexico (26.3° N, 99.5° W: paleocoordinates 30.8° N, 83.8° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Lower Member (Midway Formation), Thanetian (59.2 - 56.0 Ma)

• The Midway Formation of northeastern Mexico is divided into upper and lower divisions (members). The lower member roughly correlates to the Kincaid and Clayton Formations of the Gulf Coastal Plain. Collection is form a limestone with faunal similarities to the Kincaid Formation.

• bed-level stratigraphic resolution

Environment/lithology: lithified, shelly/skeletal, brown, gray, sandy limestone

• Carbonate. No paleoenvironmental data reported.
• Grayish-brown sandy limestone, highly fossiliferous, riddled by the soluution of the calcite in the numerous molluscan shells.

Size class: macrofossils

Preservation: original aragonite, original calcite, replaced with calcite

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 42895: authorized by Austin Hendy, entered by Austin Hendy on 06.08.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Exhaustive for mollusca.
Bivalvia
 Ostreida - Ostreidae
 Cardiida - Cardiidae
Gastropoda
 Neogastropoda - Buccinidae
Pseudoliva nana true whelk
 Neogastropoda - Volutidae
"Volutospina (Eoathleta) corvocada" = Athleta (Volutospina)
"Volutospina (Eoathleta) corvocada" = Athleta (Volutospina) volute
 Neogastropoda - Turridae
 Naticoidea - Naticidae
Cephalopoda
 Nautilida - Hercoglossidae
"Hercoglossa cf. vaughani" = Cimomia vaughani
"Hercoglossa cf. vaughani" = Cimomia vaughani Gardner 1923 nautiloid