Remarkable set of tracks suggests different dinosaurs herded together

Late Cretaceous dinosaur tracks found in Canada might have been made by different species walking together, but the evidence is far from conclusive

By Michael Le Page

23 July 2025

Artwork showing a herd of ceratopsians accompanied by an ankylosaur walking through an old river channel, watched by two tyrannosaurs

Julius Csotonyi

Did different species of plant-eating dinosaurs herd together for protection like many modern animals do? A set of 76-million-year-old tracks discovered in Canada might be the first evidence of this – but the case is far from closed.

Last year, Brian Pickles at the University of Reading, UK, and his colleagues discovered parallel tracks in Dinosaur Provincial Park in Alberta that were made by at least five individual animals.

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“They’re all next to each other, and they’re equally spaced,” says Pickles. “So it suggests that they’re approximately shoulder to shoulder.”

Initially, the researchers thought all the tracks were made by ceratopsians, horned dinosaurs such as the famous Triceratops. They can’t be sure exactly which ceratopsid made the tracks, but fossil bones show that species such as Styracosaurus albertensis were present in the area at the time.

“As we were excavating, we realised that one of these sets of tracks wasn’t like the others,” says Pickles. “It’s about the same size, but it’s got three toes, and the only large animals that make footprints like that in the park at that time are ankylosaurs. So what we have is an ankylosaur in amongst a bunch of ceratopsians.” Ankylosaurs were heavily armoured dinosaurs with club-like tails.