OMNH V794, Mussentuchit (Cretaceous of the United States)

Where: Emery County, Utah (38.7° N, 111.2° W: paleocoordinates 40.0° N, 73.4° W)

• coordinate estimated from map

• small collection-level geographic resolution

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

• 15 m below overlying Naturita Fm.

•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: crevasse splay; mudstone

Size classes: macrofossils, mesofossils

Primary reference: R. L. Cifelli and S. K. Madsen. 1998. Triconodont mammals from the medial Cretaceous of Utah. Journal of Vertebrate Paleontology 18(2):403-411 [J. Alroy/J. Alroy/M. Carrano]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 14403: authorized by John Alroy, entered by John Alroy on 21.09.1998, edited by Roger Benson and Matthew Carrano

Creative Commons license: CC BY (attribution)

Taxonomic list

 Squamata - Polyglyphanodontidae
Bicuspidon numerosus6 Nydam and Cifelli 2002 squamates
 Theropoda -
Theropoda "indet. 1"5 Marsh 1881 theropod
teeth, morphotype 1
Theropoda "indet. 2"5 Marsh 1881 theropod
teeth, morphotype 2
Theropoda "indet. 3"5 Marsh 1881 theropod
teeth, morphotype 3
 Theropoda - Dromaeosauridae
Richardoestesia sp.5 Currie et al. 1990 maniraptoran
teeth, morphotype 4
 Loricata - Goniopholididae
Goniopholididae indet.5 Cope 1875 crocodilian
 Multituberculata -
Cedaromys parvus4 Eaton and Cifelli 2001 multituberculate
including tentatively referred m1
Cedaromys bestia4 Eaton and Nelson 1991 multituberculate
including tentatively referred M2
cf. Paracimexomys perplexus n. sp.4 Eaton and Cifelli 2001 multituberculate
Bryceomys intermedius4 Eaton and Cifelli 2001 multituberculate
 Multituberculata - Plagiaulacidae
? Plagiaulacidae indet.4 Gill 1872 multituberculate
 Multituberculata -
Janumys erebos4 Eaton and Cifelli 2001 multituberculate
Ameribaatar zofiae n. gen. n. sp.4 Eaton and Cifelli 2001 multituberculate
holotype M2, OMNH 33984; m2, 33992; M2, 27583, 27616 (anterior portion), 33984;
 Eutriconodonta - Triconodontidae
Corviconodon utahensis Cifelli and Madsen 1998 mammal
 Theriamorpha -
Adelodelphys muizoni2 Cifelli 2004 metatherian
Sinbadelphys schmidti2 Cifelli 2004 metatherian
Dakotadens pertritus3 Cifelli et al. 2016 metatherian
OMNH 27641, 27640, 27644, 33997–33998, 30588
 Theriamorpha - Spalacotheriidae
Spalacolestes cretulablatta1 Cifelli and Madsen 1999 mammal
Spalacotheridium noblei1 Cifelli and Madsen 1999 mammal