[N] 2006 Fossil footprints from the Lower Cantwell Formation, Alaska
Fiorillo, A., Breithaupt, B. & McCarthy, P. (2006) Dinosauria and Aves fossil footprints from the Lower Cantwell Formation (Upper Cretaceous), Denali National Park, Alaska. JVP 26(3) Abstracts pp.61
The Cantwell Formation (Upper Cretaceous to lower Tertiary) is a thick rock unit that crops out in much of the central part of Denali National Park. The lower part of this succession is dominantly comprised of fine-grained channel and floodplain sedimentary facies.Floodplain deposits contain abundant evidence of weak pedogenesis, including root traces, blocky structure, iron oxide mottles and nodules, suggesting widespread poorly drained conditions in a highly aggradational setting. The upper Cantwell succession is largely volcanic.
The lower Cantwell Formation correlates in age with the famous dinosaur-bearing rocks of the Prince Creek Formation of the North Slope of Alaska, as well as the dinosaurbearing Chignik Formation of Aniakchak National Park in southwestern Alaska. Three new vertebrate fossil sites have been discovered in Denali National Park. The first locality, located in the Igloo Creek drainage, yielded the natural cast of an isolated right pes of a medium-sized theropod. The track measures approximately 22 cm in length and 15 cm in width, which provides an estimated hip height of approximately 90 cm and a body length of approximately 3 m
A second site, located on Double Mountain, produced an impression of a theropod approximately the same size as the previous. The remaining locality, also on Double Mountain, is in a lacustrine facies and has yielded dozens of tracks attributable to mediumsized wading birds, approximately the size of a modern Willet or an American Avocet. The morphology of the tracks indicates the substrate was still very wet when these birds walked on the surface. There are also numerous small, nearly circular depressions, approximately 3 mm in diameter, on the same bedding plane. These features are likely the feeding traces of these shore birds. Combined, these tracks represent the first record of Late Cretaceous fossil vertebrates from Denali National Park as well as the Alaska Range.