This Cretaceous-Era Pterosaur Is One Of The Largest Flying Animals Ever Discovered


The Cryodrakon boreas, clearly awestruck by the Northern Lights. Credit: David Mass

Boasting a wingspan equivalent to two giraffes (or a single telephone pole), a newly identified species of pterosaur, named Cryodrakon boreas, is one of the largest flying animals ever discovered. This is according to a paper published in the Journal of Vertebrate Paleontology

This gigantic beast could grow to lengths of up to 10 meters (32 feet) wing tip to wing tip and would have lived some 77 million years ago, during the Cretaceous period, alongside dinosaurs like the Hadrosaurus and the Panoplosaurus. And yet, despite its bird- (or dragon-) like appearance, it was not a dinosaur but a member of the Azhdarchid group of pterosaurs – a family of flying reptiles that includes the Arambourgiania and the (relatively) diminutive Montanazhdarcho. 

An artist's impression of the Cryodrakon boreas looks like a cross between a stork and the Canadian flag (inspired by its place of origin). Credit: David Maas

Pterosaurs like these were carnivores, snacking on small animals such as lizards, mammals, and baby dinosaurs. However, unlike the majority of pterosaur groups, azhdarchids were predominantly terrestrial and tended to stay inland. In spite of this preference, palaeontologists believe it is likely they had the capacity to cross oceans by flying. But because of this preference (and their thin-walled, highly pneumatic bones), their appearance in the fossil record is comparatively uncommon.

The remains discussed in the paper – a skeleton containing part of the wings, legs, neck, and a rib – were found over 30 years ago in Alberta, Canada, at a site called the Dinosaur Park Formation. Until very recently, palaeontologists mistook its identity for an already known species of azhdarchid found in Texas – Quetzalcoatlus. But contemporary analysis shows that it is, in fact, an entirely new species and the very first pterosaur to be discovered in Canada. Its name Cryodrakon boreas translates to “cold dragon of the north winds.”

The main skeleton is from a youngster and researchers estimate its wingspan is approximately 5 meters (16 feet). However, a large neckbone from an adult individual also found at the site suggests it could have a wingspan up to 10 meters long, which puts it in a league (heightwise) with other giant azhdarchids (the biggest group of pterosaurs) like the Quetzalcoatlus. Quetzalcoatlus had wingspans of up to 10.5 meters (35 feet) long and weighed around 250 kilograms (550 pounds). 

Right humerus of Cryodrakon boreas (upper arm bone), approx. 25 centimeters long. Credit: David Hone

The team says Cryodrakon is likely to have been of the same size and build as the Quetzalcoatlus, and would have shared analogous flight performance characteristics and flight muscle fractions. Though they believe Cryodrakon was slightly heavier and slightly more robust in the neck than Quetzalcoatlus


"It is great that we can identify Cryodrakon as being distinct to Quetzalcoatlus as it means we have a better picture of the diversity and evolution of predatory pterosaurs in North America," David Hone, lead author of the study from Queen Mary University of London, UK, said in a statement.