Newly Identified Pterosaur Species Among the Largest Animals to Have Ever Flown


Researchers from Queen Mary University of London, the University of Southern California, and the Royal Tyrrell Museum of Palaeontology studied pterosaur material from Dinosaur Provincial Park in Alberta, Canada. The specimens studied are identified as a new genus and speciesCryodrakon boreas, giving new insights into pterosaur diversity and evolution.

Illustration of Cryodrakon boreas. Artwork courtesy of David Maas.

The azhdarchids were a group of large and diverse Cretaceous pterosaurs (often incorrectly called ‘pterodactyls’ or ‘flying dinosaurs’). The largest adult flying reptiles had wingspans of over 10 m. Azhdarchids are known from limited and fragmentary remains, which makes studying them difficult. Unlike most pterosaur groups, azhdarchids are known primarily from terrestrial settings. Despite their likely capacity to cross oceanic distances in flight, they are broadly considered to be adapted for inland environments.

Numerous pterosaur fossils have been discovered in Dinosaur Provincial Park (DPP) over the last 30 years. These elements, which include a partial skeleton that preserves partial wings, legs, neck, and a rib, are ~76.5 million years old and were presumed to belong to an already known genus of pterosaur, the giant Quetzalcoatlus. Discovered in Texas, and about the size of a Cessna airplane, Quetzalcoatlus is one of the best-known pterosaurs in North America due to the amount and quality of preserved material.

A Royal Tyrrell Museum technician working in a pterosaur quarry in DPP in the early 1990s.

Study of the partial skeleton and additional material uncovered over the years reveals that the DPP pterosaur belongs to a totally different kind of animal in light of the growing understanding of azhdarchid diversity and, as such, was given the name Cryodrakon boreas, which means “cold dragon of the North winds.” The partial skeleton represents a young animal with a wingspan of about five metres, but one isolated giant neck bone from another specimen suggests that Cryodrakon could have reached a wingspan of around 10 metres when fully grown.

This suggests that Cryodrakon boreas was of a similar size as other giant azhdarchids, including the Texan Quetzalcoatlus that could reach 10.5 m in wingspan and weighed around 250 kg. Like other azhdarchids, these animals were carnivorous. They hunted small animals, which likely included lizards, mammals, and even baby dinosaurs.

View overlooking DPP. The rock from the Dinosaur Park Formation was laid down between 76.7 and 74.3 million years ago.

Cryodrakon is one of the geologically oldest azhdarchids known from North America. This research confirms the presence of giant azhdarchids in North America from at least 76.5 million years ago. Despite their large size and a distribution across North and South America, Asia, Africa and Europe, few azhdarchid pterosaurs are known from more than fragmentary remains. This makes Cryodrakon an important animal since it has well-preserved bones, and includes multiple individuals of different sizes.