Cow Island, Missouri River (Cretaceous to of the United States)

Also known as M. sphenocerus type

Where: Blaine County, Montana (47.8° N, 108.9° W: paleocoordinates 54.7° N, 75.1° W)

• coordinate based on nearby landmark

• small collection-level geographic resolution

When: Judith River Formation (Montana Group), Middle Campanian to Middle Campanian (83.5 - 70.6 Ma)

• bed-level stratigraphic resolution

Environment/lithology: terrestrial; lithology not reported

Size class: macrofossils

Collected by C. Sternberg in 1876; reposited in the AMNH

Collection methods: quarrying, mechanical,

Primary reference: E. D. Cope. 1889. The horned Dinosauria of the Laramie. The American Naturalist 23:715-717 [M. Carrano/M. Carrano/M. Carrano]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 46122: authorized by Matthew Carrano, entered by Matthew Carrano on 04.01.2005

Creative Commons license: CC BY (attribution)

Taxonomic list

 Neornithischia - Ceratopsidae
Monoclonius sphenocerus n. sp. Cope 1889 ceratopsid
AMNH 3989