north of Upton (Cretaceous of the United States)

Also known as Locality 9, Myopterygius petersoni

Where: Weston County, Wyoming (44.1° N, 104.6° W: paleocoordinates 43.7° N, 64.9° W)

• coordinate stated in text

• small collection-level geographic resolution

When: Belle Fourche Formation, Middle Cenomanian (99.6 - 93.5 Ma)

• "The specimen comes from 3 feet above the base of the Belle Fourche shale member of the Graneros formation" - but this assignment applies only in S Dakota, so this is interpreted here as Belle Fourche Fm.

• bed-level stratigraphic resolution

Environment/lithology: marine; shale

Size class: macrofossils

Collected by R. G. Gose in 1939

• "Before the specimen was excavated souvenir hunters had broken and scattered parts of the rostral portion of the skull and had removed various pieces of bone - how much is not known."

Primary reference: R., L. Nace. 1941. A new ichthyosaur from the late Cretaceous, northeast Wyoming. American Journal of Science 239(12):908-914 [M. Carrano/H. Street]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 105791: authorized by Matthew Carrano, entered by Hallie Street on 25.02.2011

Creative Commons license: CC BY (attribution)

Taxonomic list

Reptilia
 Ichthyosauria - Ophthalmosauridae
"Myopterygius petersoni n. sp." = Platypterygius americanus
"Myopterygius petersoni n. sp." = Platypterygius americanus Nace 1939 ichthyosaur
UW 5545 (rostrum, opisthotic, stapes, rib fragments, vertebrae, partial scapula, right femur, assorted paddle elements)