The Nugget Sandstone is a Late Triassic to Early Jurassic geologic formation that outcrops in Colorado, Idaho, Wyoming, and Utah, western United States.
In Wyoming, it is composed of a lower hematite-stained siltstone and thin-bedded sandstone. The upper part is a salmon-pink and light-gray, fine- to medium-grained cliff-forming sandstone that exhibits massive bedding to large scale cross-beds of dunes. Thickness ranges up to 86.9 m (285 feet).Johnson, J.F. and Sutherland, W.M., 2009, Geologic map of the Lander 30' x 60' quadrangle, Fremont County, Wyoming, Wyoming State Geological Survey, Map Series MS-87, 1:100,000.
Fossil theropod tracks have been reported from the formation.Weishampel, et al. (2004). "Dinosaur distribution." Pp. 517-607.
Fossil content Intermediate theropod, sphenosuchian, drepanosaurid and sphenodontian remains are known.B. B. Britt, D. J. Chure, G. F. Engelmann and J. D. Shumway. 2016. Rise of the erg—paleontology and paleoenvironments of the Triassic-Jurassic transition in northeastern Utah. Geology of the Intermountain West 3:1-32
Paleofauna reported from the Nugget Sandstone Genus Species Material Notes Images Caelestiventus C. hanseni Most of the skull, a complete lower jaw, a finger bone A dimorphodontid pterosaur; one of the earliest known diagnostic pterosaurs in North America.
Other fossils Rhynchosauroides sp. Lepidosauria indet.
Ichnofossils Batrachopus sp. Brachychirotherium sp. Brasilichnium sp. Cochlichnus sp. Diplichnites sp. Grallator (Eubrontes) Gwyneddichnium sp. Octopodichnus sp. Otozoum sp. cf. Paleohelcura sp. Pterichnus sp. Scoyenia sp. Treptichnus sp. ?Acanthichnus sp. ?Apatopus sp.
See also List of pterosaur-bearing stratigraphic units List of dinosaur-bearing rock formations List of stratigraphic units with theropod tracks
References
Bibliography Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp.
Further reading