Twin Rivers, UCMP A3682 (Oligocene of the United States)

Where: Clallam County, Washington (48.2° N, 123.9° W: paleocoordinates 47.9° N, 115.4° W)

• coordinate based on nearby landmark

When: Pysht Formation (Twin River Group), Late/Upper Oligocene (28.4 - 23.0 Ma)

• formation-level stratigraphic resolution

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 208152: authorized by Mark Uhen, entered by Mark Uhen on 22.03.2020

Creative Commons license: CC BY (attribution)

Taxonomic list

Bivalvia
 Solemyida - Solemyidae
"Solemya dalli" = Solemya (Acharax) dalli
"Solemya dalli" = Solemya (Acharax) dalli Clark 1925 Awning Clam
 Nuculida - Nuculidae
"Acila gettysburgensis" = Acila (Acila) gettysburgensis
"Acila gettysburgensis" = Acila (Acila) gettysburgensis Regan 1909 divaricate nutclam
 Lucinida - Lucinidae
 Lucinida - Thyasiridae
"Thyasira cf. disjuncta" = Conchocele bisecta
"Thyasira cf. disjuncta" = Conchocele bisecta Conrad 1849 clam
 Thraciida - Periplomatidae
Scaphopoda
 Dentaliida - Dentaliidae
"Dentalium conradi" = Dentalium pseudonyma
"Dentalium conradi" = Dentalium pseudonyma Pilsbry and Sharp 1898 tusk shell
Gastropoda
 Sorbeoconcha - Cassidae
"Echinophoria rex" = Liracassis rex
"Echinophoria rex" = Liracassis rex Tegland 1931 snail