Where: Contra Costa County, California (38.0° N, 122.1° W: paleocoordinates 37.3° N, 118.1° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Briones Formation, Serravallian (13.8 - 11.6 Ma)

• Said to come from the Sobrante Sandstone, but the area is now mapped as the Briones Sandstone. Detrital zircons provide a maximum depositional age of 13.6 ± 0.2 Ma for the underlying Hambre Sandstone (earliest Serravallian). The overlying Orinda Formation yielded a radiometric date of around 10.84 ± 0.01 Ma (early Tortonian) near its base. The collection could be earliest Tortonian, but most of the Briones Sandstone should be Serravallian in age.

• group of beds-level stratigraphic resolution

Environment/lithology: coastal; lithified siliciclastic sediments

Size class: macrofossils

Reposited in the UCMP

Primary reference: J. D. Nations. 1975. The genus Cancer (Crustacea: Brachyura): systematics, biogeography and fossil record. Natural History Museum of Los Angeles County Science Bulletin 23:1-104 [C. Schweitzer/C. Schweitzer]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 226542: authorized by Matthew Clapham, entered by Matthew Clapham on 14.07.2022

Creative Commons license: CC BY (attribution)