OMNH V868, 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)

• 8 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.

• group of beds-level stratigraphic resolution

Environment/lithology: crevasse splay; lithology not reported

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 14405: 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 -
Dimekodontosaurus madseni6 Nydam 2002 squamates
Primaderma nessovi5 Nydam 2000 squamates
Scincomorpha indet.6 Camp 1923 squamates
 Squamata - Polyglyphanodontidae
Bicuspidon numerosus7 Nydam and Cifelli 2002 squamates
 Squamata -
Bothriagenys mysterion6 Nydam 2002 squamates
 Squamata - Teiidae
Harmodontosaurus emeryensis n. gen. n. sp.6 Nydam 2002 squamates
OMNH 33889
 Theriamorpha -
Adelodelphys muizoni2 Cifelli 2004 metatherian
 Theriamorpha - Stagodontidae
Pariadens mckennai n. sp.2 Cifelli 2004 metatherian
OMNH 33072, holotype left m4; OMNH 33076 (m1) and 33971 (m2 or 3)
 Theriamorpha -
Sinbadelphys schmidti2 Cifelli 2004 metatherian
 Theriamorpha - Spalacotheriidae
Spalacotheriidae indet.3 Marsh 1887 mammal
Spalacotheridium noblei1 Cifelli and Madsen 1999 mammal
Spalacolestes inconcinnus n. sp.3 Cifelli and Madsen 1999 mammal
Spalacolestes cretulablatta1 Cifelli and Madsen 1999 mammal
 Multituberculata -
Ameribaatar zofiae4 Eaton and Cifelli 2001 multituberculate
ml, OMNH 32990 (partial); m2, 32993; M2, 32989 (posterior fragment), 32991 (partial)
Janumys erebos4 Eaton and Cifelli 2001 multituberculate
Bryceomys intermedius n. sp.4 Eaton and Cifelli 2001 multituberculate
including tentatively referred m2
cf. Paracimexomys perplexus4 Eaton and Cifelli 2001 multituberculate
cf. Paracimexomys cf. robisoni4 Eaton and Nelson 1991 multituberculate
Cedaromys parvus4 Eaton and Cifelli 2001 multituberculate
Cedaromys bestia4 Eaton and Nelson 1991 multituberculate
 Eutriconodonta - Triconodontidae
Astroconodon delicatus Cifelli and Madsen 1998 mammal