A pygmy version of the ferocious Tyrannosaurus Rex was discovered in northern Alaska by two paleontologists who nearly overlooked the novel find.
Named Nanuqsaurus hoglundi, the 70 million-year-old dinosaur was roughly 20 feet long. Its name comes from the Alaskan Inupiat word Nanuq, which means “polar bear lizard.” The fossils were found in 2006 when paleontologists were searching for another horned dinosaur in the Prince Creek formation in northern Alaska.
“I never thought I’d see a dwarf tyrannosaur come to light,” Thomas Carr, a paleontologist at Carthage College in Kenosha, Wis., who was not involved in the research, told Nature on Wednesday, referring to how the Nanuqsaurus is about half the size of its famous cousin.
The findings, published in the journal PLOS ONE, describe how the newfound dinosaur’s relatively small size may have been an adaptation to its Arctic environment. While Alaska was warmer than it is today, during the Cretaceous period the region would have still experienced seasonal temperature extremes that would have affected the dinosaur’s food supply. This goes against a common rule found in biology, which posits that animals get bigger the further north they are found, like the polar bear, which uses its fat reserves to stay warm in its polar environment.
"It's a pretty surprising discovery," paleontologist Matt Lamanna, of the Carnegie Museum of Natural History in Pittsburgh, who wasn't involved in the new study, told National Geographic. "In the modern world you tend to find big stuff at the Poles, and it's interesting that in the Cretaceous world you don't."
Analysis of the dinosaur’s skull revealed that it had an inflated area of the brain that focuses on smell, which may mean it relied on scent – like the T. rex did – to pursue its prey.
The fossils belonging to the new pygmy dinosaur were found on the soil’s surface inside a rock the size of a football. The rock remained unopened since the team was largely focused on another unknown dinosaur, the Pachyrhinosaurs perotorum, also known as the Perot dinosaur. It was only last year when paleontologists began to work on the rock and uncovered the skull belonging to a previously unidentified dinosaur species.
Tykoski said the shape of the skull resembled a T. rex, but the dinosaur’s small teeth led him to believe it belonged to a new species.
Discoverer Tony Fiorillo says that the latest paleontological discovery is among one of his favorites.
“I love all of my children equally,” he told the Alaska Dispatch. “This one is amazing and cool. I’m so excited by it. The Perot dinosaur was the same thing. All it tells me is there’s so much potential to be had.”