One of the largest creatures ever to fly on this planet had a wingspan about the length of a school bus and soared through the skies of Western Canada.

Fossils for the winged pterosaur, dubbed the cryodrakon boreas -- or 鈥渇rozen dragon of the north wind鈥 -- were found in Alberta 30 years ago. But researchers initially mistook the remains for that of a similar, previously known species.

But contends that the fossils are that of an entirely new flying reptile with a wingspan of up to 10 metres.

The uncovered skeleton -- which consisted of the wings, legs, neck and a rib -- is believed to be that of a juvenile cryodrakon. Full-grown, the ancient lizard would have weighed about 250 kilograms -- slightly more than a full-grown pony, according to researchers.

Cryodrakons are believed to have been carnivores that preyed upon small animals such as lizards, mammals and smaller dinosaurs. They would have lived in the region about 76.6 million years ago during the Cretaceous period.

Artist renderings show the cryodrakon鈥檚 plumage as a red-and-white pattern reminiscent of the Canadian flag. Researchers don鈥檛 actually know the pterosaur鈥檚 colour, and the pattern is simply a nod to where the fossils were found.

The fossils were unearthed in Dinosaur Provincial Park east of Calgary.

Researchers from Queen Mary University of London, the University of Southern California and the Royal Tyrell Museum of Paleontology were part of the study.