Researchers Identify Dinosaur Species 5 Times Larger Than Tyrannosaurus: 'This Is Very Exciting'

Researchers have discovered a new species of dinosaur that loomed over the tyrannosaurus.

The Calgary Herald reports that University of Calgary scientists helped identify the massive new species named Ulughbegsaurus, which roamed the earth as an apex predator 90 million years ago.

Researchers were able to identify the new species through the dinosaur's fossilized jaw, which was likely first found by a Russian paleontologist during a dig in the 1980s. Darla Zelenitsky, a University of Calgary associate professor of paleontology, said the tyrannosaurus that lived at the same time as Ulughbegsaurus would have been just one-fifth the size of the larger dino's body mass, per CBC.

The fossil later caught the eye of researchers Dr. Kohei Tanaka and Zelenitsky. After Tanaka initially identified fossils from Ulughbegsaurus in 2019, the two scientists searched for another piece of the predator and found it in the previously unearthed jaw. After using 3-D modeling to link fossilized teeth to the jaw, they were able to identify the new species.

Zelenitsky said that Ulughbegasaurus was so large that they "probably kept the tyrannosaurus down" and "were obviously better apex predators." When Ulughbegasaurus died out, tyrannosaurs were able to grow larger and assume the predator role.

Zelenitsky explained, "The disappearance of [Ulughbegasaurus] likely allowed tyrannosaur species to become the apex predators of Asia and North America some 80 to 90 million years ago, who persisted in large forms like Albertosaurus, Gorgosaurus, and T-Rex."

The scientist said that she was "surprised" they had only just identified "such a large predator" now, calling the discovery "very exciting."

The researchers found that the dinosaur was between 7.5 to eight meters (24 to 26 feet) in length and likely weighed over 1,000 kilograms (2,204 lbs). At the time Ulughbegasaurus roamed the earth, the tyrannosaurus wasn't fully evolved into the predator we recognize today, and and was much smaller at just under 200 kilograms (440 lbs).

Comparing the two species, Zelenitsky said Ulughbegasaurus "was like a grizzly bear" if tyrannosaurus of the time had been a coyote.

Zelenitsky also noted a difference in the two dinos' eating habits, explaining that Ulughbegasaurus "had slashing bites with blade-like teeth, whereas the smaller tyrannosaurus' jaws were more for crushing bones."

Ulughbegasaurus disappeared about 89 million years ago, and scientists are still searching for reasons why.