Where: Uintah County, Utah (40.4° N, 109.3° W: paleocoordinates 41.2° N, 70.9° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Mussentuchit Member (Cedar Mountain Formation), Early/Lower Cenomanian (99.6 - 93.5 Ma)

• 27 m above base of Cedar Mountain Fm, near base of member; zircon age is middle Albian, chemostratigraphic age is early Albian.

•A radiometric age of 98.37 ± 0.07 Ma was obtained by the OMNH from volcanic ash within the Mussentuchit Member (Cifelli and others, 1997, 1999). Additional ages by Garrison and others (2007) ranging from 96.7 ± 0.5 to 98.2 ± 0.6 Ma indicate that the Mussentuchit Member was deposited over an interval of 1.5 Ma during the early Cenomanian and supports a correlation with the siliceous marine Mowry Shale to the north, which is well-constrained from 40Ar/39Ar sanidine ages obtained from bentonite beds that bracket the Mowry in Wyoming; the basal Arrow Creek Bentonite is 98.5 ± 0.5 Ma and the capping Clay Spur Bentonite is 97.2 ± 0.7 Ma (Obradovich, 1993; Ogg and Hinnov, 2012; Sprinkel and others, 2012) near the base of the Upper Cretaceous. Tucker et al. 2020 also suggested a likely depositional age of ~96-94 Ma for the Musseuntuchit member.

• bed-level stratigraphic resolution

Environment/lithology: fluvial; medium-grained sandstone and mudstone

Size classes: macrofossils, mesofossils

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

Primary reference: D. J. Chure, B. B. Britt, J. A. Whitlock and J. A. Wilson. 2010. First complete sauropod dinosaur skull from the Cretaceous of the Americas and the evolution of sauropod dentition. Naturwissenschaften [M. Carrano/M. Carrano]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 94550: authorized by Matthew Carrano, entered by Matthew Carrano on 26.02.2010

Creative Commons license: CC BY (attribution)