An extraordinary set of dinosaur footprints discovered at Dinosaur Provincial Park in Alberta, Canada has revealed the first evidence of mixed-species herding behaviour in the area.
The fossilised footprints were uncovered in July 2024 at the UNESCO World Heritage Site, a rugged landscape made famous by its fossil-rich deposits. Yet, despite the incredible abundance of skeletal remains, dinosaur footprints and trackways are surprisingly rare.
Published in the journal PLOS One, the study details how the new tracksite – known as the ‘Skyline Tracksite’ – shows several dinosaur species walking side by side around 76 million years ago.
It also highlights the discovery of a second set of tracks running perpendicular to the herd; these belong to two large tyrannosaurs and could suggest the apex predators were stalking the group – “a pretty chilling thought”, says co-author Dr Phil Bell from the University of New England.
Discovering footprints at Dinosaur Provincial Park
Dinosaur Provincial Park has long been a hotspot for fossil discoveries. Over the past century, palaeontologists have uncovered more than 50 species of dinosaur, including fossils of tyrannosaurs, hadrosaurs and ceratopsians. The newly identified set of footprints adds to the list of impressive finds.
“I’ve collected dinosaur bones in Dinosaur Provincial Park for nearly 20 years, but I’d never given footprints much thought,” says Bell. “This rim of rock had the look of mud that had been squelched out between your toes, and I was immediately intrigued.”
Using picks, trowels and hammers to break up the mudstone, and corn brooms, paintbrushes and dustpans to clean it, the research team excavated 29 square metres of the rock surface.
The work revealed 13 ceratopsian (horned dinosaur) footprints from at least five animals walking together. An ankylosaurid (armoured dinosaur) appeared to be moving within the ceratopsian group, and a single footprint of a small meat-eating dinosaur was also found.
The team was particularly struck by two large tyrannosaur footprints moving side-by-side, at right angles to the herd. This may suggest the herd was moving together to protect themselves from predators, although further evidence is needed to confirm the behaviour, say the researchers.
“The tyrannosaur tracks give the sense that they were really eyeing up the herd, which is a pretty chilling thought,” Bell explains, “but we don’t know for certain whether they actually crossed paths.”
Co-author Dr Brian Pickles from the University of Reading says, “It was incredibly exciting to be walking in the footsteps of dinosaurs 76 million years after they laid them down.
“Using the new search images for these footprints, we have been able to discover several more tracksites within the varied terrain of the Park,” Pickles adds, “which I am sure will tell us even more about how these fascinating creatures interacted with each other and behaved in their natural environment.”
Top image: Skyline Tracksite. Credit: Dr Brian Pickles, University of Reading
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