A Probable Tyrannosaurid Track from the Hell Creek Formation (Upper Cretaceous), Montana, United States

摘要

Large theropod tracks have previously been attributed to Tyrannosaurus rex. Most identifications however, have not been supported by either clear comparison with T. rex osteology or the stratigraphic position of the track. There is a conspicuous absence of tracks in the Upper Cretaceous (Maastrichtian) Hell Creek, Lance, Scollard, Frenchman, and Denver Formations (Lancian, North American Land Mammal Age), where T. rex body fossils have been found. A large tridactyl track is described here from the Hell Creek Formation of Carter County, Montana, United States. This find constitutes the first record of a large theropod track from the Hell Creek Formation, which could have potentially been made by T. rex or another large theropod, based on the track morphology and stratigraphic position.