Where: San Bernardino County, California (35.0° N, 116.8° W: paleocoordinates 34.1° N, 111.3° W)

• coordinate estimated from map

• small collection-level geographic resolution

When: Upper Member (Barstow Formation), Hemingfordian (20.4 - 16.0 Ma)

• Overlying fine-grained lacustrine beds (here referred to as the Calico Member of the Barstow Formation) are bracketed between ca. 19 and 16.9 Ma, and are thus older than the type section of the Barstow Formation in the Mud Hills. Several 17.1-16.8 Ma calc-alkaline dacite domes intrude the Calico Member.

• group of beds-level stratigraphic resolution

Environment/lithology: lacustrine - large; lithified, concretionary mudstone

Size class: mesofossils

Preservation: adpression, concretion

Collection methods: bulk, chemical, acetic,

• "Over 1000 concretions were collected and etched in a 10% acetic acid bath... residues were examined to identify and assess the relative anatomic preservation of fossils"

•University of Arizona collection

Primary reference: L. E. Park and K. F. Downing. 2001. Paleoecology of an exceptionally preserved arthropod fauna from lake deposits of the Miocene Barstow Formation, Southern California, U.S.A. Palaios 16(2):175-184 [J. Alroy/J. Alroy]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 106431: authorized by John Alroy, entered by John Alroy on 15.03.2011

Creative Commons license: CC BY (attribution)