Palaeontologists in southern Alberta discovered one of the oldest tyrannosaur species ever to be unearthed in North America.

This is the first time in 50 years that tyrannosaur remains have been discovered in the area, according to Lonely Planet.

Illustration by Julius Csotonyi. Image: Royal Tyrrell Museum of Palaeontology

Dr. François Therrien, Curator of Dinosaur Palaeoecology at the Royal Tyrrell Museum said: 

‘We are thrilled to announce the first new species of tyrannosaur to be discovered in Canada in 50 years,’

The last tyrannosaur discovered in Canada was Daspletosaurus in 1970.

There are only four other tyrannosaur species known to be from Canada: Daspletosaurus, Gorgosaurus, Albertosaurus, and Tyrannosaurus.

Scientists say the species, named the Thanatotheristes degrootorum, is a direct relative of the Tyrannosaurus rex and is believed to be around 79.5-million years old.

Most dinosaur species from the Alberta region date back to between 77 – 66 million years old. There are only two other dinosaurs known from the same time period as Thanatotheristes: a dome-headed dinosaur (Colepiocephale) and a horned dinosaur (Xenoceratops).

Scientists from the University of Calgary and the Royal Tyrrell Museum of Palaeontology published an article in the Cretaceous Research journal, stating that the Thanatotheristes is approximately 2.5-million years older than its closest relative.

In comparison to a full-grown T-Rex, which grew to be aproximately 12m in length, this species grew to about 9m long and weighed around 2 tons.

John de Groot, a farmer and palaeontology enthusiast, found the fossil skull fragments while hiking near Hays, Alberta.

He said:

‘The jawbone was an absolutely stunning find. We knew it was special because you could clearly see the fossilized teeth,’

Image: John and Sandra De Groot

By analyzing the unique features of the fossil’s skull fragments, scientists were able to decisively conclude that this is a new, distinct species.

Jared Voris, a University of Calgary Ph.D. student, and lead author of the study said:

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,’

Dr Therrien added:

‘This discovery is significant because it fills in a gap in our understanding of tyrannosaur evolution,’

Thanatotheristes provides scientific insights into the complex tyrannosaur family tree.

The name of the species was inspired by Thanatos (Greek god of death) and theristes (one who reaps or harvests). The second part of the name honours the farming routes of the De Groot family.