The Tyrannosaurus Rex has long been the creature of nightmares — but the "King of Tyrant Lizards" had a cousin who may have been just as terrifying. With the help of a paleontology enthusiast, scientists in Canada said they discovered the newest member of the Tyrannosaurus family and named it after the Greek God of Death.

The dinosaur, named Thanatotheristes degrootorum, is the first new tyrannosaurus species to be discovered in Canada in 50 years. At approximately 79.5 million years old, it is also the oldest of the five tyrannosaur species to be discovered in the country. The other four — Daspletosaurus, Gorgosaurus, Albertosaurus, and Tyrannosaurus — are between 77 and 66 million years old.

Introducing the first new species of tyrannosaur discovered in Canada in 50 years. Meet Thanatotheristes degrootorum, the ‘reaper of death’! Read all about it on our blog: https://bit.ly/37c3S7x Posted by Royal Tyrrell Museum of Palaeontology on Monday, February 10, 2020

Thanatotheristes degrootorum is 2.5 million years older than its closest relative.

The Thanatotheristes degrootorum is Canada's first new tyrannosaur species in 50 years. juliuscsotonyi

Scientists believe the dinosaur was an apex predator of the area, and named it as such. Its genus name Thanatotheristes is derived from Thanatos, which means "Greek god of death," and theristes, which means "one who reaps or harvests." The species name, degrootorum, is named for paleontology enthusiast and farmer John De Groot, who found the remains of the dinosaur while on a hike near Hays, Alberta, according to the Royal Tyrrell Museum.

Get Breaking News Delivered to Your Inbox

In the museum's press statement, De Groot said the discovery of the fossil skull fragments, including the jawbone, was "an absolutely stunning find."

"We knew it was special because you could clearly see the fossilized teeth," he said.

François Therrien, curator of dinosaur palaeoecology at the Royal Tyrrell Museum, announced the discovery on Facebook with University of Calgary Ph.D. candidate Jared Voris. "This discovery is significant because it fills in a gap in our understanding of tyrannosaur evolution," he said.

Voris, the lead author of the study, said scientists concluded the fossils were a new species by analyzing the fragments De Groot found. The fossils have unique features that separate them from those of other members of the tyrannosaur family.

Canada's newest dinosaur discovery was named after the Greek God of Death. juliuscsotonyi

"Thanatotheristes can be distinguished from all other tyrannosaurs by numerous characteristics of the skull," Voris said. "But the most prominent are vertical ridges that run the length of the upper jaw."

A rendering of the dinosaur shows large teeth for eating meat. Scientists believe the animal was a bi-pedal predator, similar to the T. Rex.

The discovery has been included in the journal Cretaceous Research.