Ankylosaur footprints from Canada are first of their kind in the world

Emily Chung · CBC News

· Posted: Apr 16, 2025 4:52 PM EDT | Last Updated: 6 minutes ago

Scientists person identified fossil dinosaur footprints from a caller taxon successful B.C. and Alberta. They're believed to beryllium the archetypal tracks recovered successful the satellite to beryllium identified arsenic belonging to club-tailed ankylosaurs, offering caller insights astir gaps successful the fossil record.

The caller species, which has been named Ruopodosaurus clava, would person been an armoured dinosaur astir 5 to six metres long, reports a caller survey published this week successful the Journal of Vertebrate Paleontology. 

Victoria Arbour, curator of paleontology astatine the Royal B.C. Museum and pb writer of the caller study, said Ruopodosaurus would person lumbered done the coastal redwood forests betwixt the Rocky Mountains and an inland oversea that covered Saskatchewan and Alberta during the Middle Cretaceous, astir 100 million to 94 cardinal years ago. Previously identified footprints suggest the different creatures it lived alongside: elephantine crocodiles, duck-billed dinosaurs and bird-like dinosaurs — and a related radical of four-toed ankylosaurs. 

But nary bones of three-toed, club-tailed ankylosaurs person ever been recovered successful North America from the Middle Cretaceous, which, until now, suggested they whitethorn person gone extinct during this time, earlier reappearing astir 84 cardinal years ago, possibly by the migration of populations from Asia. The tracks from this caller taxon suggest otherwise. 

This species, Arbour said, is "new for North America. It's caller for the world…. And it truly helps america capable successful this spread successful the fossil record."

A communicative of 2 ankylosaurs

Like two-toed and three-toed sloths, determination are 2 intimately related branches of ankylosaurs with antithetic numbers of toes:

• Ankylosaurids, which person 3 toes, and are celebrated for their process clubs, which were either slim and stiff similar a shot bat, oregon circular similar the 1 connected the celebrated well-preserved ankylosaur Zuul crurivastator, which lived astir 75 cardinal years ago.

WATCH | Dinosaur Cold Case: Armoured Dinosaurs, featuring Zuul

• Nodosaurids, which person 4 toes, a flexible tail, and a longer snout. Many had large enarthrosis spikes, including Borealopelta ankylosaur, a well-preserved specimen recovered an an oilsands excavation successful 2011.  

WATCH | Meet 1 of the world's best-preserved dinosaurs, featuring Borealopelta

Nodosaurid prints were archetypal recovered astatine Tumbler Ridge by 2 boys, 11-year-old Mark Turner and eight-year-old Daniel Helm, successful 2001. That led to the find of different dinosaur trackways and fossils successful the region, and the founding of the Tumbler Ridge Museum.

What scientists learned about the caller species

Arbour archetypal saw photos of the antithetic tracks successful the caller survey astir 5 years ago. Some were recovered adjacent Tumbler Ridge and others astatine a state good connected the different broadside of the B.C.-Alberta border.

"I thought they were truly unusual and absorbing looking and I was truly funny astir them," she recalled. 

Then successful 2023, she visited the Tumbler Ridge Museum, and Charles Helm, Daniel's begetter and the scientific advisor astatine the museum, suggested they survey the tracks together, on with some  caller ones that helium and Daniel had found. Many included not conscionable three-toed footprints, but the crescent-shaped, 5 fingered handprints that ankylosaurs are known to have.

"And I got truly excited," Arbour said. "I was like, 'You know, I deliberation the lone happening these truly tin beryllium … is an ankylosaurid."

The probe confirmed that, and named the caller taxon Ruopodosaurus clava, which means "tumbled-down lizard with a club/mace" referring to the determination they were recovered and the distinctive diagnostic of this ankylosaur family.

Arbour said fossils recovered successful China suggest that astatine this time, process clubs were conscionable starting to germinate successful ankylosaurids, truthful this taxon whitethorn not person had a afloat circular nine similar Zuul.

Almost each the footprints were akin successful size — astir 30 centimetres long — suggesting that the mean size of this taxon was astir 5 oregon six metres long, oregon smaller than galore ankylosaurs without process clubs. Sometimes aggregate trackways were recovered together, each heading successful the aforesaid absorption and ne'er crossing, suggesting respective animals whitethorn person been travelling together.

Anthony Shillito is simply a University of Saskatchewan researcher who has antecedently studied dinosaur trackways from the Cretaceous that included four-toed ankylosaur footprints. He said footprints from three-toed ankylosaurs whitethorn person been recovered before, but determination are truthful galore three-toed dinosaurs that they would person been hard to place without the distinctive handprints that were recovered with the footprints successful Canada.

"[The study] truly made maine deliberation backmost to immoderate of the footprints I've seen — maybe I misinterpreted it due to the fact that I didn't person this information," helium said. "Now radical person a amended thought of what they're looking for." And that whitethorn pb to much being found, and a amended thought of wherever other these club-tailed ankylosaurs whitethorn person lived during the Middle Cretaceous, helium suggested.

The worth of footprints vs. bones

Paleontologist Scott Persons studied some fossil dinosaur tracks and ankylosaurs during his PhD astatine the University of Alberta, and is presently moving connected the survey of a caller nodosaur species. 

He said successful showing that ankylosaurids lived successful North America earlier than thought, the caller survey demonstrates the worth of looking astatine some fossil footprints and bones. Those often get preserved nether antithetic conditions and incorporate antithetic information.

"If you lone look astatine fossil bones, you whitethorn beryllium missing fractional the puzzle pieces," said Persons, curator of the Mace Brown Museum of Natural History and adjunct prof astatine the College of Charleston successful South Carolina.

He noted that trackways often amusement aggregate taxon that lived unneurotic astatine the aforesaid time, and tin uncover different information. This caller trackway besides shows that wide, squat ankylosaurs — sometimes described arsenic being coffee-table-like — had a amazingly bird-like gait, lining up near and close feet similar "supermodels connected a runway."

He added, "This way grounds shows america the java array analogy is simply a small spot flawed."

On the different hand, helium acknowledged, determination is 1 drawback of footprints compared to bones.

"The evident question is: What bash these animals look like? All we person are the feet."