Also known as NDGS 10838

Where: Cavalier County County, North Dakota (49.0° N, 98.5° W: paleocoordinates 53.4° N, 63.2° W)

• coordinate estimated from map

When: Pembina Member (Pierre Shale Formation), Middle Campanian (83.5 - 70.6 Ma)

• The lower bound on the age of the specimen is 80.04 ± 0.11 Ma, calculated for the Q3 bentonite bed at the study area that is situated approximately 3.5 meters below the bone layer.

•The bone layer is situated between five and 5.5 meters above the contact with the underlying Niobrara Formation.

• bed-level stratigraphic resolution

Environment/lithology: offshore; yellow shale

Size class: macrofossils

• A nearly complete skull (missing only the nasals, braincase, parietal, septomaxilla, and scleral ossicles), complete mandibles, all seven cervical vertebrae, 11 disarticulated ribs, and five articulated anterior dorsal vertebrae. Several unprepared jackets, which were not found until after the submission of this manuscript, contain additional postcranial material including ribs, a scapula, and a coracoid.

Collected by D. Shepherd in 2015–2018

Collection methods: quarrying, surface (in situ), mechanical,

• NDGS, North Dakota State Fossil Collection, North Dakota Geological Survey, Bismarck

Primary reference: A. R. Zietlow, C. A. Boyd, and N. E. Van Vranken. 2023. Jormungandr walhallaensis: a new mosasaurine (Squamata: Mosasauroidea) from the Pierre Shale Formation (Pembina Member: Middle Campanian) of North Dakota. Bulletin of the American Museum of Natural History 464:1-82 [E. Vlachos/F. Aspromonte/P. Mannion]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 232234: authorized by Evangelos Vlachos, entered by Franco Aspromonte on 02.11.2023

Creative Commons license: CC BY (attribution)