A dinosaur fossil from the Canadian High Arctic is the most northern ever discovered.

The fossil vertebra, part of the backbone of a duck-billed dinosaur called a hadrosaur, was discovered on Axel Heiberg Island in Nunavut at a latitude of about 75 degrees north – 500 kilometres further north than any permanent human settlement, said paleontologist Matthew Vavrek, lead author of a new paper describing the fossil. The paper was published in the journal Arctic.

Hadrosaurs are a group of plant-eating dinosaurs, including Edmontosaurus, with duck-like bills and sometimes crests on their head. The size of the Arctic bone suggests that it was from a hadrosaur about eight-metres long.

"This find up in the High Arctic is kind of unique because we found it on what at the time was kind of a relatively isolated part of North America. These animals would have been living in this area year round," said Vavrek in an interview that airs Saturday on CBC's Quirks & Quarks.

During the late Cretaceous period about 100 to 66 million years ago, when the Arctic hadrosaur lived, he added, its home was part of an island separated from the rest of North America by two seas, running from the Arctic Ocean to the Gulf of Mexico, and one cutting through northern Saskatchwan and Manitoba.

Arctic hadrosaur vertebra

The fossil vertebra, part of the backbone of a duck-billed dinosaur called a hadrosaur, was discovered on Axel Heiberg Island in Nunavut. (Courtesy Matthew Vavrek)

That means it couldn't have migrated south during the winter.

Vavrek, curator and head paleontologist at the Philip J. Currie Dinosaur Museum in Grand Prairie, Alta., said the discovery helps show the true range of where dinosaurs once lived.

During the Late Cretaceous, North America was rotated such that Axel Heiberg Island was a little further south than it is now but still above the Arctic Circle.

Temperatures averaged 15 degrees warmer and were far less extreme than they are in the region today. However, the Arctic still featured 24 hours of sunlight at the height of summer and 24 hours of darkness at the winter solstice.

Because of that, there wouldn't have been a lot of plants to eat in the winter.

Vavrek suggests that the Arctic hadrosaur survived by eating some of the things found in the stomachs and fossilized feces of hadrosaurs that lived further south, such as twigs and branches, and decaying wood that contained nutritious fungi.

"These dinosaurs definitely could have survived up in that area year round, living on this low-grade plant matter."

Vavrek said paleontologists have barely looked for dinosaur fossils in the Canadian High Arctic because it's so expensive and logistically difficult to get there, and because the permafrost tends to break up fossil skeletons as it churns through its freeze-thaw cycles. But he thinks there may still remain many dinosaurs left to be found there.