Frozen Dragon of the North (image) University of Southern California Share Print E-Mail Caption Fossil discovery shows new species of pterosaur, Cryodrakon boreas, that dominated the skies above North America about 75 million years ago. Credit David Maas Usage Restrictions Full credit for illustration (David Maas). Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.