Forbes Shale

The Forbes Shale is a geologic formation in the Sacramento Valley of northern California, United States. It is found in the Sutter Buttes area of Sutter County, California. It preserves fossils dating back to the Coniacian stage of the Late Cretaceous period.

Fossil content
The following fossils were reported from the formation:
 * Bivalves


 * Cladoceramus undulatoplicatus
 * Glycymerita veatchii
 * Inoceramus subundatus
 * I. Inoceramus vancouverensis
 * I. aff. chicoensis
 * I. aff. klamathensis
 * I. aff. whitneyi
 * Parallelodon|Parallelodon (Nanonavis) brewerlanus
 * Pseudomelania colusaensis


 * Gastropods


 * Bernaya (Protocypraea) kayei
 * Biplica obliqua
 * Dentalium (Entalis) whiteavesi
 * Pseudomelania colusaensis
 * Tessarolax distorta
 * Volutoderma californica


 * Ammonites


 * Baculites chicoensis
 * B. inornatus
 * Desmophyllites diphylloides
 * Eupachydiscus arbucklensis
 * E. willgreeni
 * Eutrephoceras campbelli
 * Lytoceras (Gaudryceras) alamedense
 * Nowakites dobbinsi
 * N. rumseyensis
 * Oxybeloceras petrolense
 * Parapachydiscus cortinaensis
 * Puzosia (Holcodiscoides) gorrilli
 * Puzosia (Parapuzosia) arenaica
 * Baculites sp.
 * Canadoceras sp.
 * Hauericeras sp.