Quetzalcoatlus

Quetzalcoatlus was a pterosaur known from the Late Cretaceous of North America and the largest known member of the Azhdarchidae, a family of advanced toothless pterosaurs with unusually long, stiffened necks. Its name comes from the Mesoamerican feathered serpent god Quetzalcoatl.

When it was first discovered, scientists estimated that the largest Quetzalcoatlusfossils came from an individual with a wingspan as large as 15.9 meters, choosing the middle of three extrapolations from the proportions of other pterosaurs that gave an estimate of 11, 15.5 and 21 meters respectively. In 1981, further study lowered these estimates to 11–12 meters. More recent estimates based on greater knowledge of azhdarchid proportions place its wingspan at 10–11 meters.

Mass estimates for giant azhdarchids are extremely problematic because no existing species share a similar size or body plan, and in consequence published results vary widely. While some studies have historically found extremely low weight estimates for Quetzalcoatlus, as low as 70 kilograms for a 10-meter individual, a majority of estimates published since the 2000s have been higher, around 200–250 kilograms.