NEW MATERIAL OF MESADACYLUS ORNITHOSPHYOS, A PRIMITIVE PTERODACTYLOID PTEROSAUR FROM THE UPPER JURASSIC OF COLORADO
David K. Smith, R. Kent Sanders, and Kenneth L. Stadtman, Journal of Vertebrate Paleontology, 2004, 24(4):850–856
The Dry Mesa Dinosaur Quarry in western Colorado is characterized by a high diversity of vertebrate fossils, including pterosaur remains. Most of the pterosaur material has been referred to the species Mesadactylus ornithosphyos. Since its original description, additional material of this pterosaur has been uncovered. The new material includes the first described well-preserved basicranium of a Jurassic pterodactyloid pterosaur from North America and several appendicular elements. The cervical vertebra described previously was CT-scanned to reveal a complicated internal pneumatic system that can be compared to the avian system.