Twin Rivers, UCMP A3685 (Oligocene of the United States)

Where: Clallam County, Washington (48.2° N, 123.9° W: paleocoordinates 47.8° N, 115.0° W)

• coordinate based on nearby landmark

When: Twin Rivers Formation, Late/Upper Oligocene (28.4 - 23.0 Ma)

Environment/lithology: marine; lithified shale

Size class: macrofossils

Primary reference: J. W. Durham. 1944. Megafaunal zones of the Oligocene of northwestern Washington. University of California Publications in Geological Sciences 27:101 -212 [P. Holroyd/E. Orzechowski]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 208155: authorized by Mark Uhen, entered by Mark Uhen on 22.03.2020

Creative Commons license: CC BY (attribution)

Taxonomic list

Rhynchonellata
 Rhynchonellida - Hemithirididae
"? Hemithyris "sp. B"" = Hemithiris
"? Hemithyris "sp. B"" = Hemithiris d'Orbigny 1847
Gastropoda
 Sorbeoconcha - Cassidae
"Echinophoria rex" = Liracassis rex
"Echinophoria rex" = Liracassis rex Tegland 1931 snail
Bivalvia
 Pectinida - Limidae
Lima robertsae n. sp. Durham 1944 file clam