Where: Jefferson County, Washington (48.1° N, 122.7° W: paleocoordinates 47.7° N, 111.9° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Marrowstone Formation, Rupelian (33.9 - 28.1 Ma)

• "Turritella porterensis zone of Marrowstone shale (middle Oligocene)." Map in Armentrout & Berta (1977) places this site in the Marrowstone Formation. On the basis of magnetostratigraphy, Prothero et al. (2009) assigned the Marrowstone to the earliest Oligocene (Chron C13n) and placed the Eocene-Oligocene boundary in the underlying Quimper Formation. Armentrout & Berta (1977) assigned an upper Refugian age on the basis of benthic foraminifera and correlated it with the early Oligocene.

• group of beds-level stratigraphic resolution

Environment/lithology: deep-water; lithified, silty shale

Size class: macrofossils

Collected by J. Wyatt Durham; reposited in the UCMP

Primary reference: A. K. Miller and H. R. Downs. 1950. Tertiary nautiloids of the Americas: supplement. Journal of Paleontology 24:1-18 [M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 180419: authorized by Matthew Clapham, entered by Matthew Clapham on 16.07.2016, edited by Mark Uhen

Creative Commons license: CC BY (attribution)