Where: Ventura County, California (34.3° N, 119.0° W: paleocoordinates 32.9° N, 110.8° W)

• coordinate based on political unit

• small collection-level geographic resolution

When: Leptauchenid Zone Member (Sespe Formation), Arikareean (29.5 - 18.5 Ma)

• Mason and Swisher 1989: "An overall age of 28.2 ± 0.2 Ma (weighted average) is indicated for the Willard Canyon tuff..." which is "60 m (200 ft.) above the top of Stock's (1934) "Leptauchenid Zone," and about 337 m (1100 ft.) above the type locality of Sespia californica." CIT 157 is within the Leptauchenid Zone.

Environment/lithology: fluvial-lacustrine; sandstone and red mudstone

Size class: macrofossils

Reposited in the LACM

Primary reference: M. A. Mason and C. C. Swisher. 1989. New evidence for the age of the South Mountain local fauna, Ventura County, California. Contributions in Science, Natural History Museum of Los Angeles County 410:1-9 [J. Alroy/J. Alroy/P. Holroyd]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 17677: authorized by John Alroy, entered by John Alroy on 26.03.1995

Creative Commons license: CC BY (attribution)