The first record of a Cretaceous dinosaur from southwestern Alaska

Cretaceous dinosaurs are recorded for the first time from southwestern Alaska by a series of three tracks found in Aniakchak National Monument. This trackway is in the Upper Cretaceous (Campanian–Maastrichtian) Chignik Formation, a cyclic sequence of marine to non-marine clastic sedimentary rocks. The nearest coeval locality is approximately 1500 km northeast of this site, along the Colville River in northern Alaska, which contains abundant dinosaurs. This distance helps to document the occurrence of a widespread Cretaceous Arctic terrestrial ecosystem that supported significant numbers of large-bodied herbivores.