Paleoecology

Dinosaur tracks in the Maastrichtian part of the North Horn Formation form an ichnofacies (Figs. 3A, 5) whose existence is likely owed to conditions provided by anastomosed fluvial environments. Chaotic trampled beds record the progressive encroachment of rivers or the overflow of levees into ephemeral wetlands on the floodplain. Many of the dinosaur footprint depressions were preserved by rapid burial when they were filled with sand, as fluvial action periodically transported sand into the...

Description Of Track Beds At North Horn Mountain

The North Horn Formation dinosaur track beds occur in cross-sectional outcrop view in single or successive sandstone beds. In these beds, the tracks may be stacked vertically and are viewed in cross-section, so they are not true trackways, in which a series of repeated tracks are seen in plan view to indicate directional locomotion. Dinosaur tracks often are found at the base of sandstone ledges, ribbons, and fins between beds and beneath the levee edges (Fig. 3A, B). Track beds in outcrop may...

Track Beds At Other Localities

Dinosaur track beds occur also at other Wasatch Plateau localities Fig. 1 in Black Dragon Canyon and at Flagstaff Peak Emery County , in Fairview Canyon San-pete County , and in Price Canyon Carbon County . Track beds identical to those at North Horn Mountain occur 5 km southwest at the Lizard Locality in Black Dragon Canyon, the type locality of the Cretaceous lizard Polyglyphanodon Gilmore, 1942 39 09.95' N, 111 16.36' W . A nest site containing in situ dinosauroid eggshells...

References

Anderson, B.G., Barrick, R.E., Droser, M.L., and Stadtman, K.L., 1999, Hadrosaur skin impressions from the Upper Cretaceous Neslen Formation, Book Cliffs, Utah Morphology and paleoenvi-ronmental context in Gillette, D.D., ed., Vertebrate Paleontology in Utah Utah Geological Survey Special Publication No. 99-1, Salt Lake City, p. 295-301. Bakker, R.T., 1986, The Dinosaur Heresies, New Theories Unlocking the Mystery of the Dinosaurs and Their Extinction Zebra Books, Kensington Publishing Corp.,...

North Horn Formation Stratigraphy

Crevassesplay Facies Deposits

The North Horn type section 39 11.40'-13.00' N, 111 14.21'-15.00' W is 403 m thick Fig. 2 , and it provides a reference section for the other localities. The formation is Maastrichtian in its lower portion and Paleocene in the upper. It consists of three lithostratigraphic units, and these can be subdivided further based on lithologic and pa-leontologic differences. Unit 1, the lowest unit, consists chiefly of variegated mudstone interbedded with fine-grained, heavily biotur-bated sandstone...

Location And Previous Work

The study area includes several localities of the North Horn Formation in the Wasatch Plateau, central Utah Fig. 1 1 North Horn Mountain and Black Dragon Canyon are located on the east-central edge of the Wasatch Plateau west of Castle Dale 2 Flagstaff Peak is located on the Wasatch Plateau south of North Horn Mountain 3 Fairview Canyon is located on the west central slope of the Wasatch Plateau east of Fairview and 4 Price Canyon is located on the northern slope of the Wasatch Plateau,...