Where: Butte County, California (39.8° N, 121.7° W: paleocoordinates 47.1° N, 90.4° W)

• coordinate based on nearby landmark

• local area-level geographic resolution

When: Chico Formation, Early/Lower Campanian (83.5 - 70.6 Ma)

• Str. position: Chico formation (s.s.) in the type area, lower part of the upper half of the formation

•Fossils: Canadoceras yokoyamai (JIMBO)*, Pachydiscus buckhami USHER*, Sub­mortoniceras chicoense (TRASK)* (a large number of specimens showing variation), Ryugasella ryugasensis WRIGHT & MATSUMOTO*, Pseudoxybeloceras lineatum (GABB) *, Baculites chieoensis TRASK*, many other shells

•Age: Campanian (probably relatively lower part)

• member-level stratigraphic resolution

Environment/lithology: marine; silty sandstone

Size class: macrofossils

Collected by R. E. Cook in 1947 - 1948; reposited in the CAS

Primary reference: T. Matsumoto. 1960. Upper Cretaceous ammonites of California. Part III. Memoirs of the Faculty of Science, Kyushu University Series D, Geology, Special Volume II 1-204 [A. Hendy/A. Hendy/A. Hendy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 225634: authorized by Jonathan Marcot, entered by Jonathan Marcot on 20.05.2022

Creative Commons license: CC BY (attribution)