Martin Lockley, Kyung Soo Kim & Jong Deock Lim (2021)
Tetrapodosaurus trackways from the Cretaceous of Colorado and Canada: observations on variability in ankylosaurian gaits.
In: Lucas, S. G., Hunt, A. P. & Lichtig, A. J., 2021, Fossil Record 7. New Mexico Museum of Natural History and Science Bulletin 82: 227-235
https://www.researchgate.net/publication/348293559_TETRAPODOSAURUS_TRACKWAYS_FROM_THE_CRETACEOUS_OF_COLORADO_AND_CANADA_OBSERVATIONS_ON_VARIABLITY_IN_ANKYLOSAURIAN_GAITSThe Cretaceous ankylosaurian ichnogenus Tetrapodosaurus is only found abundantly in two regions, in North America: in the Aptian-Albian Gething and Gates Formations of western Canada and the Albian-Cenomanian Dakota and Naturita Formations of Colorado. While tracks from both regions have been reported in a number of papers, the Colorado discoveries are comparatively recent and have not previously been described in detail. Here we describe the configuration of trackways from the Colorado sites and compare them with the Canadian tracks which include the type ichnospecies (Tetrapodosaurus borealis). The results indicate some intra-and inter-trackway variability in trackway gauge suggestive of a corresponding variability in trackmaker size and gait, within the range of normal walking speed.