USGS 26790 [Myrtle Fm] (Cretaceous of the United States)

Where: Douglas County, Oregon (43.3° N, 123.2° W: paleocoordinates 41.4° N, 71.7° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Myrtle Formation, Valanginian (139.8 - 132.9 Ma)

• STRATIGRAPHIC RELATIONS: From the Myrtle Fm. AGE: Valanginian, on the basis of macrofossil biostratigraphy. STRATIGRAPHIC POSITION: From 119 ft above 3rd conglomerate in local section.

• bed-level stratigraphic resolution

Environment/lithology: marine; lithified siliciclastic sediments

• ENVIRONMENT: Not stated in text.
• SPECIFIC LITHOLOGY: Not stated, but probably siliciclastic. LITHIFICATION: Lithified on the basis of figured specimens.

Size class: macrofossils

Preservation: cast, mold/impression

Collected by Imlay in 1954; reposited in the USNM

Collection methods: surface (in situ),

• COLLECTORS: Imlay, Dole, and Peck, 1954. REPOSITORY: USNM, Washington, DC.

Primary reference: R. W. Imlay. 1960. Ammonites of Early Cretaceous age (Valanginian and Hauterivian) from the Pacific Coast states. United States Geological Survey Professional Paper 334(F):1-228 [A. Hendy/A. Hendy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 83584: authorized by Austin Hendy, entered by Austin Hendy on 22.08.2008

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Exhaustive for ammonoidea. Other taxonomic groups may be present but are not listed. NOMENCLATURE: Authoritative publication, with fairly modern nomenclature, and species-resolution identifications.
Cephalopoda
 Ammonitida - Olcostephanidae
Olcostephanus pecki Imlay 1960 ammonite
Olcostephanus popenoei Imlay 1960 ammonite