An international team of paleontologists from Australia, Canada and Italy has documented more than a hundred 72.5-million-year-old dinosaur footprints on the banks of the Redwillow River near Grande Prairie, Alberta, Canada. An article about this was published in the journal PLoS ONE.
Dinosaur footprints have been found in at least three different layers that have preserved clear impressions extruded into the alluvial (river) floodplain. This suggests that for a long time this area was inhabited by different groups of dinosaurs, apparently living in different parts of the ancient river system. The most numerous type of footprints is attributed to hadrosaurs of the ichnogenus Hadrosauropodus on the basis that the width of the footprints exceeds their length, the toes are wide and rounded, and the heels have characteristic edges. It is not yet possible to correlate the traces with the corresponding bone remains, therefore, instead of the usual taxa, paleontologists in the case of such fossil traces distinguish taxa-analogues, ichnotaxa – ichnogenera and ichnospecies.
“It was very important to document this site thoroughly while it’s still available to us,” said lead author Nathan Enriquez of the University of New England’s Paleoscience Research Center in Australia. — This place is covered by the waters of the Redwillow River for most of the year and is constantly eroded. By the time we found the tracks, most of the information had already been lost. Unfortunately, over time, these traces will be completely lost. However, our work ensures that all possible information contained in the footprints is digitally preserved for future generations: the most important footprints and trajectories of dinosaurs are now available as 3D models.”
The largest of the tracks was 65 cm long, suggesting that it could have been left by the largest crested hadrosaur species Edmontosaurus regalis. Three-toed footprints over 45 cm long are confidently classified by paleontologists as tyrannosaurids. This site also contains small traces of dinosaurs from the families of troodontids and ornithomimids, as well as azhdarchid pterosaurs.