New dinosaur unearthed in Alberta a significant find for the field of paleontology

He said tyrannosaurs were the dominant apex predators at the end of the Cretaceous period – the end of the age of the dinosaurs.

As for why this new species is being called the ‘reaper of death’, Therrien said that comes from the Greek origin of its scientific name.

‘Thanatos’ is the ancient Greek god of death, while ‘theristes’ means ‘to reap’.

“That kind of illustrates what this animal would have been; it would have been this big, tough predator in Alberta about 79.5 million years ago,” he remarked.

DISCOVERED BY LOCAL FAMILY

Therrien said the discovery actually occurred in 2010, when fossils were found along the Bow River east of the hamlet of Hays, Alberta, about half an hour west of Medicine Hat.

John De Groot and his wife Sandra made the find while hiking along the river, according to Therrien. He said they reported the find to the Royal Tyrrell Museum. A crew was then sent out to investigate the area and a few additional pieces were uncovered.

John De Groot with fossil pieces (Photo courtesy John De Groot)

“The specimen, at the time, we could tell it was a tyrannosaur because we had the jaw bones and the teeth, but we weren’t sure if it belonged to a totally new species,” Therrien told LNN.

“We suspected that it was because it came from rocks that are far older from the rocks form which the better-known tyrannosaurs [come from] but we weren’t sure if there were enough details because the bones were really fragmentary, we didn’t have a complete skull, we just had bones coming from different parts of the skull.”

He said that in 2018, a University of Calgary student he was working with, Jared Voris was studying young individuals from different species of dinosaurs.

When he took a look at the specimen found by the De Groot family, he noted that some of the characteristics he spotted had not been seen in any other tyrannosaur in North America and deduced that it must be a new species.

“We went back to the locality where the specimen had been discovered nine years prior, looked at the rock record and we didn’t find any additional bones but we were able to document the stratigraphy, so the rocks that were exposed in the area in order to determine what was the age of the specimen. Eventually, that led to the paper – the scientific article that came out [recently],” Therrien said.

THE BADLANDS

Therrien said in Alberta, there are now five different species of tyrannosaur linked to the province.

He explained that in most other parts of the world, mostly throughout the rest of North America and Asia, there’s usually a maximum of two to three species per state, but Alberta has the distinction of tracing five species back to area.

“Alberta is one of the best places in the world to find tyrannosaurus,” he said.

Dr. Therrien (left) with Jared Voris (Photo courtesy the Royal Tyrrell Museum of Palaeontology)

He added that every new discovery brings new information to the world of paleontology.

This latest new species, the Thanatotheristes comes from a time interval of which there have been very few fossils found.

“This discovery actually fills in a gap in our understanding of the evolution of tyrannosaurus. Now we know that it’s actually an animal – the Thanatotheristes – was on the branch leading to T-Rex but branched off just a little bit before,” he said.

“Its closest relative is actually another dinosaur from Alberta and Montana called the Daspletosaurus so then we know now that that animal was more [of] a distant cousin of the T-Rex.”

He said that by studying all the tyrannosaurus from North America, they’ve been able to determine that during a time period between 80 million and 74 million years ago, different species were actually separated.

The upper and lower jaw of the Thanatotheristes degrootorum (Photo courtesy the Royal Tyrrell Museum of Paleontology)

“The more primitive tyrannosaurus lived in the southern states, so like New Mexico and Utah. Farther north in central Alberta, we had animals like the Albertosaurus and Gorgosaurus and in between, basically on the border between Alberta and Montana, that’s where we had animals like the Daspletosaurus and Thanatotheristes that they lived there,” he explained.

“These animals didn’t seem to overlap that much. They seemed to have lived separate lives and that could [maybe] represent differences in environments, or maybe differences in types of prey. That’s why these animals kind of tried to stay apart from each other so they would not compete with one another.”

FINDING A FOSSIL

Therrien said many discoveries are made by trained professionals, but in quite a few cases, members of the public have been the ones to stumbled upon dinosaur bones.

He said when someone finds a fossil, it’s important to leave it as it is, note where it’s located and in Alberta, report the finding as soon as possible to the Royal Tyrrell Museum.

“If it’s something significant, you’ll be invited to come on the dig or on the expedition to recover fossils and if it’s a new species, that species may actually be named after you,” he added.

This latest find will eventually be put on display at the museum in Drumheller. No exact date is set in stone for that, but Therrien said visitors will be able to swing by in person to get a closer look at the Thanatotheristes.

by Justin Goulet

New dinosaur unearthed in Alberta a significant find for the field of paleontology

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