Where: Contra Costa County, California (38.0° N, 122.2° W)
• Paleocoordinates: 42.5° N, 108.6° W (Wright 2013)
• coordinate based on nearby landmark
• outcrop-level geographic resolution
When: San Ramon Formation, Chattian (28.1 - 23.0 Ma)
• Contains a fauna typical of the Agasoma gravidum beds. The ridge at this location contains the San Ramon Formation and Sobrante Formation, but only the San Ramon Formation contains the Agasoma gravidum beds. Formation generally assigned an upper Oligocene age (Hertlein & Grant, 1972; Amano, 1999), but could be Miocene.
• group of beds-level stratigraphic resolution
Environment/lithology: marine; poorly lithified siliciclastic sediments
Size class: macrofossils
Reposited in the UCMP
Primary reference: H. G. Schenck. 1931. Cephalopods of the genus Aturia from western North America. University of California Publications, Bulletin of the Department of Geological Sciences 19:435-490 [M. Clapham/K. Okamoto/M. Clapham]more details
Purpose of describing collection: taxonomic analysis
PaleoDB collection 180446: authorized by Matthew Clapham, entered by Matthew Clapham on 16.07.2016, edited by Jonathan Marcot
Creative Commons license: CC BY (attribution)
Taxonomic list
Gastropoda | |
"Bursa mathewsonii" = Mediargo mathewsoni
| |
Molopophorus biplicatus Gabb 1866 snail | |
Olivella quadriplicata Clark 1918 olive snail | |
Bivalvia | |
"Dosinia mathewsonii" = Dosinia (Dosinia) whitneyi
"Dosinia mathewsonii" = Dosinia (Dosinia) whitneyi Gabb 1866 venus clam | |
"Solen curtus" = Solena (Plectosolen) conradi, "Solen gravidus" = Solena (Plectosolen) gravidus
"Solen curtus" = Solena (Plectosolen) conradi Dall 1900 clam
"Solen gravidus" = Solena (Plectosolen) gravidus Clark 1918 clam | |
"Glycimeris tenuimbricata" = Glycymeris (Tucetona) tenuimbricata
| |
"Acila muta" = Acila (Truncacila) muta
"Acila muta" = Acila (Truncacila) muta Clark 1918 divaricate nutclam | |
Scaphopoda | |
Dentalium radiolineata Clark 1918 tusk shell type locality of ssp. Dentalium radiolineata sobrantensis
| |
Cephalopoda | |
Aturia sp. Bronn 1838 |