Station 52 La Cieba Crossing, Tumbadero (Oligocene of Mexico)

Where: Mexico (20.7° N, 97.7° W: paleocoordinates 21.4° N, 91.8° W)

• coordinate based on political unit

• local area-level geographic resolution

When: Alazan Group, Early/Lower Oligocene (33.9 - 28.4 Ma)

• 4 feet above base of exposure, overlying stations 53 and 54. Woodring (1966): this is the Palma Real Formation.

• formation-level stratigraphic resolution

Environment/lithology: marine; lithified, gray, silty claystone

• Silty clay, originally light gray , weathers to a medium fawn color

Size class: macrofossils

Primary reference: C. W. Cooke. 1928. New Vicksburg (Oligocene) Mollusks From Mexico. Proceedings from the United States National Museum 73(10):1-11 [A. Miller/K. Bulinski]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 61231: authorized by Arnold Miller, entered by Kate Bulinski on 31.05.2006

Creative Commons license: CC BY (attribution)

Taxonomic list

• the species named here include only a small part of the total number of mollusks in the Alaxan clay.
Bivalvia
 Pectinida - Pectinoidae
Amussium alazanum Cooke 1928 scallop
new species