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.
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•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
Reptilia | |
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Harmodontosaurus emeryensis n. gen. n. sp.6
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Mammalia | |
Astroconodon delicatus Cifelli and Madsen 1998 mammal | |
Spalacotheriidae indet.3, Spalacotheridium noblei1, Spalacolestes inconcinnus n. sp.3, Spalacolestes cretulablatta1
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Pariadens mckennai n. sp.2
Pariadens mckennai n. sp.2 Cifelli 2004 metatherian OMNH 33072, holotype left m4; OMNH 33076 (m1) and 33971 (m2 or 3)
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Ameribaatar zofiae4, Janumys erebos4, Cedaromys bestia4, Cedaromys parvus4, cf. Paracimexomys perplexus4, cf. Paracimexomys cf. robisoni4, Bryceomys intermedius n. sp.4
Ameribaatar zofiae4 Eaton and Cifelli 2001 multituberculate ml, OMNH 32990 (partial); m2, 32993; M2, 32989 (posterior fragment), 32991 (partial)
Bryceomys intermedius n. sp.4 Eaton and Cifelli 2001 multituberculate including tentatively referred m2
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