The Tyrannosaurus rex got the "king" moniker for a reason. But have you met his cousin?

A newly discovered tyrannosaur species named Thanatotheristes degrootorum, or "Reaper of Death" in Greek, was recently discovered in Canada.

This is the first new Tyrannosaurus species discovered in Canada in 50 years. It's also the oldest Tyrannosaurus species ever discovered in the country.

Paleontologists and researchers from the University of Calgary and the Royal Tyrrell Museum of Paleontology recently published their findings in the journal Cretaceous Research.

The authors show off their new dinosaur findings. © Royal Tyrrell Museum of Palaeontology

Tyrannosaurs were a group of large predatory theropod dinosaurs. The newly discovered Tyrannosaur revealed itself as paleontologists analyzed unique fossil skull fragments from Alberta.

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

The fossils are estimated to be 79.5 million years old. This is 2.5 million years older than its closest relative discovered in Canada.

Only two skulls of this species have been discovered, but here's what it might have looked like. Julius Csotonyi

Only four other tyrannosaurs have been found in the country. Most dinosaur species found in Alberta date between 77 and 66 million years old.

The only two other dinosaurs discovered in Alberta from the same time period as Thanatotheristes were a dome-headed dinosaur named Colepiocephale and a horned dinosaur named Xenoceratops.

Researchers believe this new Tyrannosaur was an apex predator. More importantly, this discovery revealed more information about the Tyrannosaur family tree and the late Cretaceous period.

Thanatotheristes degrootorum got its name from Thanatos, the Greek god of death, and theristes, one who reaps or harvests.

The second part of the name honors the De Groot family, who discovered the fossil fragments while hiking near Hays, Alberta.

“The jawbone was an absolutely stunning find," said John De Groot. "We knew it was special because you could clearly see the fossilized teeth."

Upper jaw ridges of the Thanatotheristes degrootorum. © Royal Tyrrell Museum of Palaeontology

Thanatotheristes had longer and deeper snouts, as well as more teeth in the upper jaws than Tyrannosaurs found in the southern U.S, according to the researchers.

Paleontologists believe the predator was over 26-feet long, 8-feet tall and had an 80-centimeter skull.

Let's just say that an encounter with the "Reaper of Death" back in the age of the dinosaurs didn't end well for many of its dino-counterparts.