Also known as COI

Where: Emery County, Utah (38.2° N, 109.6° W: paleocoordinates 39.1° N, 72.0° W)

• coordinate based on nearby landmark

• small collection-level geographic resolution

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

• lower part of member

•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 ~96-94Ma for the Musseuntuchit member.

• bed-level stratigraphic resolution

Environment/lithology: fluvial-lacustrine; fine-grained, muddy sandstone and muddy siltstone

Size classes: macrofossils, mesofossils

Preservation: trace

Collected in 2014

Collection methods: bulk, surface (in situ), chemical, sieve, ,

• reposited at the North Carolina Museum of Natural Sciences

•Approximately 183 kg of in situ sediment was collected from a fossiliferous horizon ∼15 m in width and 30 cm thick. The sediment, composed principally of a gray, highly bentonitic mudstone, was screenwashed in loads of 1,000 g using nylon paint sieves and traditional nested sieves

Primary reference: H. M. Avrahami, T. A. Gates, A. B. Heckert, P. J. Makovicky, and L. E. Zanno. 2018. A new microvertebrate assemblage from the Mussentuchit Member, Cedar Mountain Formation: insights into the paleobiodiversity and paleobiogeography of early Late Cretaceous ecosystems in western North America. PeerJ 6(e5883):1–52 [E. Vlachos/E. Vlachos]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 200123: authorized by Evangelos Vlachos, entered by Evangelos Vlachos on 15.03.2019, edited by Matthew Carrano

Creative Commons license: CC BY (attribution)