When Dinosaurs Herded Like Wildebeest

Mixed‑Species Trackways in Canada

Imagine watching a procession of horned dinosaurs marching across a floodplain, an armoured ankylosaur lumbering alongside them and two tyrannosaurs passing by at a right angle. That is the scene preserved in the latest fossil discovery from Dinosaur Provincial Park in Alberta, Canada. In July 2024 a team led by Dr Brian Pickles reported a set of trackways made by at least five ceratopsians and one ankylosaur, with two Tyrannosaurus rex trackways crossing the main trail. These footprints offer rare evidence that different dinosaur species may have travelled together, suggesting a multi‑species herd much like today’s zebras and wildebeest.

The site contains 13 ceratopsian footprints, likely from animals the size of Centrosaurus. An ankylosaur’s tracks, with wide‑set toes and a heavy tail drag, accompany them. The ceratopsian and ankylosaur tracks run parallel, implying they were laid down around the same time. Nearby, two T. rex trackways intersect the herd’s path. Researchers caution that trackways can be deceptive—the prints could represent multiple events spread over days or months. Nevertheless, the arrangement strongly hints at the sort of mixed‑species movement observed among modern herbivores. If confirmed, it would be the first footprint evidence that dinosaurs travelled in multi‑species groups.

This discovery also underlines the value of track sites for interpreting dinosaur behaviour. Skeletons tell us what a dinosaur looked like, but trackways reveal how it lived: how fast it moved, whether it walked alone or with others, and how it interacted with its environment. The Alberta site’s combination of herbivore and carnivore trails in one place provides a glimpse into a dynamic Late Cretaceous ecosystem where plant‑eaters and predators literally crossed paths. More sites like this will help palaeontologists build a richer picture of dinosaur social lives.

Credit: Jon Sullivan / Public domain

Sources: Natural History Museum press release on the mixed‑species herding trackways