A giant, flightless bird with a head equal in size to a horse's used to wander the winter landscape of the high Arctic approximately 53 million years ago, according to a team of researchers from the University of Colorado Boulder. The findings represent the first and only fossil evidence of the massive "Gastornis" bird that originates from the Arctic. The evidence stems from one fossil toe bone from the creature that mirrors similar fossil toe bones that were discovered in Wyoming and date to around the same time period.

Weighing several hundred pounds with a height around six-feet tall, the "Gastornis" (formerly "Diatryma") fossil was collected in the 1970s, although this marks the first time that it has been examined closely. Other fossils of the giant creature have been discovered in Europe and Asia.

"We knew there were a few bird fossils from up there, but we also knew they were extremely rare," Jaelyn Eberle, who participated in the research, said in a press release.

The fossil stems from a time period 53 million years ago, also called the Eocene Epoch, when the environment of Ellesmere Island, located above the Arctic Circle, was likely similar to the cypress swamps seen in the current southeast U.S. Numerous pieces of fossil evidence point to the existence of alligators, primates and other large hippo-like creatures.

Although earlier evidence pointed to the "Gastornis" being a carnivore, recent research suggests that it was likely a vegan that used its massive beak to tear apart foliage, nuts and hard fruits.

In addition to shedding light on the "Gastornis," the paper also reveals the dangers of the rapidly warming Arctic climate, which is largely a result of the increasing amount of greenhouse gases in the atmosphere due to human activity.

"Permanent Arctic ice, which has been around for millennia, is on track to disappear," Eberle said. "I'm not suggesting there will be a return of alligators and giant tortoises to Ellesmere Island any time soon. But what we know about past warm intervals in the Arctic can give us a much better idea about what to expect in terms of changing plant and animal populations there in the future."

The findings were published in the Feb. 12 issue of Scientific Reports.