'Reaper of death:' New species of tyrannosaur discovered in Canada

Doyle Rice | USA TODAY

Show Caption Hide Caption New 'reaper of death' tyrannosaur is the oldest found in Canada The species Thanatotheristes degrootorum terrorized southern Alberta 11 million years before T. Rex.

“This discovery is significant because it fills in a gap in our understanding of tyrannosaur evolution."

Tyrannosaurs were a group of large meat-eating dinosaurs that includes the famous Tyrannosaurus rex.

The first part of the new dinosaur's name alludes to its role as an apex predator.

The fossil of a new species of tyrannosaur has been discovered in Canada, according to a study released Monday.

The monstrous beast was named the "reaper of death" due to its fearsome predatory behavior.

“This discovery is significant because it fills in a gap in our understanding of tyrannosaur evolution,” study co-author Francois Therrien of the Royal Tyrrell Museum in Drumheller, Alberta, said in a statement. “We are thrilled to announce the first new species of tyrannosaur to be discovered in Canada in 50 years.”

Another co-author, Darla Zelenitsky of the University of Calgary, said in a statement “this is the oldest occurrence of a large tyrannosaur in Canada, found in an older window of time than where previous tyrannosaurs have been found."

The roughly 79.5 million-year-old fossil makes the new species 2.5 million years older than its closest relative.

The newly identified dinosaur, known by its Latin name Thanatotheristes degrootorum, provides scientists with insights into the tyrannosaur family tree and shows tyrannosaurs from the Cretaceous of Alberta were more diverse than previously known.

Tyrannosaurs were a group of large predatory meat-eating dinosaurs that included the famous Tyrannosaurus rex.

Thanatotheristes, which was approximately 30 feet long, likely preyed on large plant-eating dinosaurs, such as the horned Xenoceratops and the dome-headed Colepiochephale.

Scientists were able to identify the new species by analyzing unique features of fossil skull fragments.

“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 lead author Jared Voris, a University of Calgary Ph.D. candidate.

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The first part of the new dinosaur's name alludes to its role as an apex predator, and translates roughly to "reaper of death." It comes from the Greek god of death Thanatos and the Greek word "theristes," which means "reaper" or "harvester," the Canadian Broadcasting Corp. said.

The name's second part – degrootorum – is named after the two ranchers who discovered the fossil, John and Sandra De Groot of Hays, Alberta.

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

The study was published in the journal Cretaceous Research.