It’s been half a century since a tyrannosaur was found in Canada, but paleontologists in southern Alberta are making up for lost time. This week, researchers announced the discovery of one of the oldest tyrannosaur species ever unearthed in North America – an apex predator dubbed Thanatotheristes degrootorum, a direct relative of the Tyrannosaurus rex

A rendering of the novel Tyrannosaur called Thanatotheristes degrootorum discovered in Alberta
The new species is directly related to the T. rex © Royal Tyrrell Museum of Palaeontology

According to an article published in the journal Cretaceous Research, scientists from the University of Calgary and the Royal Tyrrell Museum of Palaeontology believe the species to be some 79.5 million years old – 2.5 million years older than its closest relative – weighing about two tons and measuring eight to nine metres (26.2 to 30ft) long as a full-grown adult. (A T. rex, on the other hand, could grow to be 12m, or 39.3ft, in length.)

A rendering of a Thanatotheristes head
An apex predator, Thanatotheristes weighed two tons and measured eight to nine metres in length © Julius Csotonyi/Royal Tyrrell Museum of Palaeontology

There are four other tyrannosaurs from Canada – Daspletosaurus, Gorgosaurus, Albertosaurus, and Tyrannosaurus – but Thanatotheristes was revealed to be a unique species from an analysis of the fossilized skull fragments that were found. “Thanatotheristes can be distinguished from all other tyrannosaurs by numerous characteristics of the skull, but the most prominent are vertical ridges that run the length of the upper jaw,” the study’s lead author, University of Calgary PhD student Jared Voris, said in a press release. 

Thanatotheristes upper and lower jaw
The find was identified as a unique species from an analysis of the fossil skull fragments that were uncovered © Royal Tyrrell Museum of Palaeontology

Interestingly, the fossil wasn’t discovered by a team of professionals, but by farmer and paleontology enthusiast John De Groot, who was hiking near his farm outside of Hays, Alberta, when he stumbled upon the skull fragments. The second part of the new tyrannosaur’s name pays tribute to his family, while the first part was inspired by the Greek god of death, Thanatos, and theristes, one who reaps or harvests.

a kid standing between the legs of a dinosaur skeleton, looking up, at the Royal Tyrrell Museum of Palaeontology
The Royal Tyrrell Museum is Canada's only museum dedicated solely to the study of ancient life © Royal Tyrrell Museum of Palaeontology

“The jawbone was an absolutely stunning find. We knew it was special because you could clearly see the fossilised teeth,” De Groot said in a press release. “There are so many dinosaur fossils in Alberta to be unearthed, and my find is by no means isolated. Many locals and visitors have spotted fossils of all kinds during leisurely strolls and hikes.”

a panoramic shot of the Royal Tyrrell Museum of Palaeontology in Alberta
Visitors to southeastern Alberta's badlands can participate in professional digs or check out one of the world's largest displays of dinosaurs at the paleontology museum © Royal Tyrrell Museum of Palaeontology

The badlands of southeastern Alberta are home to a UNESCO World Heritage Site called Dinosaur Provincial Park, where civilians can participate in guided excavation programmes at official dinosaur digs or take to the hills and go prospecting for fossils on their own. 

“Alberta has a rich dinosaur history, and we have uncovered some of the biggest finds on Earth here in the province,” Dr. François Therrien, curator of dinosaur palaeoecology at the Royal Tyrrell Museum, said in a statement. “The discovery of Thanatotheristes degrootorum is historic as it marks the first new species of tyrannosaur to be unearthed in Canada in 50 years.”

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