Where: Tehama County, California (40.2° N, 122.7° W: paleocoordinates 39.3° N, 72.2° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Stony Creek Formation, Hauterivian to Hauterivian (132.9 - 125.0 Ma)

• Stanton believed that the beds at the type locality were almost along strike with a Buchia crassicollis bed that crops out at Stephenson Place. Buchia crassicollis (Keyserling, 1864) would normally indicate O. californica as Valanginian in age, but works by Bailey and Jones (1973), Jones and Bailey (1973) and Jones et al. (1969) have shown that the area is complexly faulted, that there are no Buchia beds one km northwest of Stephenson Place and that the only beds containing O. californica in this area are either Hauterivian or Barremian in age. They reported an age range because of a lack of ammonites that would discriminate between the two ages. Stanton (1895) assigned the type locality to the upper part of the "Knoxville beds," but these beds are now known as the Stony Creek Formation

• group of beds-level stratigraphic resolution

Environment/lithology: basinal (siliceous); lithified, black mudstone and unlithified sandstone

Size class: macrofossils

Reposited in the USNM

Primary reference: R. L. Squires and L. R. Saul. 2009. Cretaceous opine bivalves from the pacific slope of North America and palaeobiogeography of subfamily Opinae Chavan, 1969. Palaeontology 52(6):1311-1347 [M. Aberhan/D. Wellmanns/S. Nurnberg]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 117991: authorized by Martin Aberhan, entered by Daniel Wellmanns on 30.09.2011

Creative Commons license: CC BY (attribution)