Cliffs of Insanity: Early/Lower Cenomanian, Utah
collected 2014

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Amphibia - Temnospondyli - Albanerpetontidae
Albanerpeton sp. Estes and Hoffstetter 1976
1 specimen
NCSM 33278, dentary bearing three complete teeth and one tooth fragment
Reptilia - Ornithischia
Ornithischia indet. Seeley 1888
5 specimens
NCSM 33322, 33318, 33316, 33312, 33314; teeth
Reptilia
Hadrosauroidea indet. Huene 1954
3 specimens
NCSM 33320, 33321, 33323 ("possibly referable to Eolambia caroljonesa")
Theropoda indet. (Marsh 1881)
31 specimens
20 tooth fragments, 11 bone fragments
Reptilia - Elongatoolithidae
Macroelongatoolithus sp. Li et al. 1995
28 specimens
NCSM 33364, 33363, 33365; eggshell fragments
Reptilia
Coelurosauria indet. Huene 1914
1 specimen
NCSM 33268, tooth
Paronychodon sp. Cope 1876
3 specimens
NCSM 33277, 33298, 33308; teeth
Reptilia - Dromaeosauridae
Dromaeosauridae indet. Colbert and Russell 1969
2 specimens
NCSM 33275, NCSM 33267, teeth
Richardoestesia sp. Currie et al. 1990
2 specimens
NCSM 33274, 33288; teeth
Reptilia
Aves indet. Linnaeus 1758
2 specimens
NCSM 33299, 33300; teeth
Tyrannosauroidea indet. Walker 1964
1 specimen
NCSM 33276, premaxillary tooth
Reptilia - Tyrannosauridae
? Tyrannosauridae indet. Osborn 1906
1 specimen
NCSM 33268, tooth
Reptilia
Mesoeucrocodylia indet. Whetstone and Whybrow 1983
3659 specimens
NCSM 33284, 33286, 33305, 33315, 33270, 33289, 33290, 33362, 33384 (incl. teeth similar to those of bernissartids, atoposaurids, pholidosaurids)
cf. Dakotasuchus sp. Mehl 1941
NCSM 33269
Reptilia - Squamata
? Squamata indet. Oppel 1811
1 specimen
NCSM 33295, tooth
Reptilia
Scincomorpha indet. (Camp 1923)
1 specimen
NCSM 33293, scincomorphan (paramacellodid–cordylid grade) tooth
? Scincomorpha indet. (Camp 1923)
1 specimen
NCSM 33296, jaw fragment
Reptilia - Testudines - Adocidae
Adocidae indet. Cope 1869
NCSM 33387, 33381, 33382 (likely new species)
Reptilia
Helochelydridae indet. (Nopcsa 1928)
NCSM 33380, 33383, 33388 (new species, previously referred to Naomichelys speciosa)
Mammalia
Marsupialia indet. (Illiger 1811)
1 specimen
NCSM 33355, incomplete upper, second premolar
Sinbadelphys schmidti Cifelli 2004
1 specimen
NCSM 33354, mesial half of R upper molar
Actinopteri
Neopterygii indet. Regan 1923
165 specimens
Approximately 112 teeth, 53 complete or partial scales, and additional skeletal and vertebral fragments; NCSM 33297, 33361
Actinopteri - Aulopiformes - Enchodontidae
cf. Enchodontidae indet. Woodward 1901
2 specimens
NCSM 33307, 33308
Actinopteri - Amiiformes - Amiidae
Amiinae indet. Bonaparte 1837
NCSM 33292
Actinopteri - Lepisosteiformes
Lepisosteiformes indet. Hay 1929
56 specimens
> 56 partial scales
Actinopteri - Lepisosteiformes - Lepisosteidae
Lepisosteidae indet. Cuvier 1825
three morphotypes of teeth; NCSM 33279, 33282
Actinopteri - Pycnodontiformes
Pycnodontiformes indet. Berg 1937
NCSM 33304, 33303
see common names

Geography
Country:United States State/province:Utah County:Emery
Coordinates: 38.2° North, 109.6° West (view map)
Paleocoordinates:39.1° North, 72.0° West
Basis of coordinate:based on nearby landmark
Geographic resolution:small collection
Time
Period:Cretaceous Epoch:Late/Upper Cretaceous
Stage:Cenomanian 10 m.y. bin:Cretaceous 5
Key time interval:Early/Lower Cenomanian
Age range of interval:100.50000 - 93.90000 m.y. ago
Age estimate:98.2 ± 0.6 to 93 Ma (unknown)
Stratigraphy
Formation:Cedar Mountain Member:Mussentuchit
Stratigraphic resolution:bed
Stratigraphy comments: 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.
Lithology and environment
Primary lithology:fine sandstone
Includes fossils?Y
Lithology description: The microvertebrate fossils described here were recovered from a fine-grained sandstone sandwiched between siltstone-dominated units, approximately five meters below the contact with the overlying Naturita Formation. Five geologic samples above, within, and below the fossil layer were collected along a section ∼1 m high (Fig. 1E). These samples indicate the COI microfossil assemblage displays a coarsening upward sequence from siltstone below the fossil-bearing layer to a bentonitic, fine-grained sandstone within it and then a transition back to siltstone above the fossil-bearing layer, possibly representing an oxbow lake with an adjacent river migrating towards the lake. Precise locality information for this site is recorded at the NC Museum of Natural Sciences.
Environment:fluvial-lacustrine indet.
Taphonomy
Modes of preservation:body,trace
Size of fossils:macrofossils,mesofossils
Collection methods and comments
Collection methods:bulk,surface (in situ),chemical,sieve,field collection,survey of museum collection,observed (not collected)
Minimum sieve size:0.500 Maximum sieve size:5.000
Collection size:6339 specimens
Rock censused:183 kg
Reason for describing collection:taxonomic analysis
Collection dates:2014
Collection method comments: 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
Metadata
Also known as:COI
Database number:200123
Authorizer:E. Vlachos, M. Carrano Enterer:E. Vlachos, M. Carrano
Modifier:M. Carrano
Created:2019-03-15 18:25:53 Last modified:2023-09-19 11:20:11
Access level:the public Released:2019-03-15 18:25:53
Creative Commons license:CC BY
Reference information

Primary reference:
68173. 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 1-52 [E. Vlachos/E. Vlachos]