UCMP loc. 2249, Rock Creek (Eocene of the United States)

Also known as Big Rock Creek

Where: Los Angeles County, California (34.4° N, 117.9° W: paleocoordinates 36.9° N, 100.8° W)

When: San Francisquito Formation, Early/Lower Eocene (55.8 - 48.6 Ma)

Environment/lithology: marine; lithified, quartzose, gray sandstone and shale

• The Martinez Group, consisting of two divisions: (a) a lower predominantly sandstone member, and (b) an upper predominantly shale member. This group rests upon the eroded surface of the basement complex on the north side of Pinyon Ridge. It is of lower Eocene age, its basal portion yielding a fauna characteristic of that horizon.

Size class: macrofossils

Collected by R. E. Dickerson, Emerson Butterworth, Edward Brainerd; reposited in the UCMP

Primary reference: R. E. Dickerson. 1914. The Martinez Eocene and associated formations at Rock Creek on the western border of the Mohave Desert area. University of California Publications Bulletin of the Department of Geology 8(141):289-298 [J. Marcot/J. Marcot]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 203578: authorized by Mark Uhen, entered by Mark Uhen on 20.08.2019, edited by Jonathan Marcot

Creative Commons license: CC BY (attribution)

Taxonomic list

Bivalvia
 Lucinida - Lucinidae
"Phacoides muirensis" = Claibornites (Codalucina) muirensis
"Phacoides muirensis" = Claibornites (Codalucina) muirensis Dickerson 1914 clam
 Cardiida - Veneridae
Saxidomus noblei n. sp. Dickerson 1914 venus clam
Echinoidea
 Cidaroida - Cidaridae
Cidaris sp. Leske 1778 pencil urchin
 Cassiduloida - Cassidulidae
Catopygus cajonensis Kew 1920 sea urchin