Researchers discovered the dinosaur's remains in 2006 in the Prince Creek Formation on Alaska's North Slope. At the same quarry, Fiorillo and Tykoski have previously uncovered other important finds, such as remnants of the horned dinosaur species Pachyrhinosaurs perotorum, whose discovery was announced in 2011.

"I find it absolutely thrilling that there is another new dinosaur found in the polar region," Fiorillo said in a statement from the Perot Museum. "It tells us that the ecosystem of ancient Arctic was a very different place, and it challenges everything we know about dinosaurs."

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A Tyrannosaurus rex would have weighed between 7 and 8 tons, with a length of about 40 feet. By comparison, an adult Nanuqsaurus might have been only 25 feet long, with a weight of 1,000 pounds. The head was probably about 2 feet long, CNN affiliate WFAA reported.

"There were features in these specimens that were unique; you didn't see them in other tyrannosaurs," Tykoski told WFAA.