



Yet it was concluded that neither azhdarchids nor any other flying reptiles were suited for skimming so the hypothesis was dropped. They lacked the jaws and neck structure for such a lifestyle, so any fishing pterosaurs would either have to dive for their prey or simply pluck fish off the water’s surface.





More recently, the azhdarchids were cast as stork-like terrestrial stalkers that picked up small animals while walking overland on dry ground. This model worked, with the animals swallowing up almost anything that could fit into their mouths. Thus the azhdarchids spent more time on land rather than close to the water. An animal the size of Quetzalcoatlus could consume victims as large as small dinosaurs, picking them up in its huge toothless jaws.





Despite this terrestrial hunting, Quetzalcoatlus and kin were incredible aeronauts. Like all flying reptiles, they launched off the ground in a four-footed leap. This launch style was supported by an immense amount of power. Quetzalcoatlus’ torso, though small in comparison to its body, was very dense and packed with huge muscles. A single leap could get one of these giants into the air, and it needed just a few flaps to keep it aloft. They could likely travel nonstop for 16,000 kilometers after launching, only rarely flapping to keep themselves in the air and to steer their path. Its short wings were not just thin membranes of skin, but densely packed muscle fibers called actinofibrils. Like all other pterosaurs, Quetzalcoatlus was warm-blooded and had an incredible metabolism to power its lifestyle.





Quetzalcoatlus occupied the role of medium-level hunter. It was midway between the contemporary tyrannosaurs and the smaller dromaeosaurs or raptor dinosaurs by way of size and choice of prey. Two species of this genus existed in the southern parts of North America, specifically in the Javelina Formation of Texas.





The bigger one, the huge Quetzalcoatlus northropi stood as tall as a giraffe on the ground, more than five meters tall and weighed 250 kilograms. This is the maximum weight limit for a flying animal, and only a few other azhdarchids come close to Q.northropi’s size. The smaller species is Quetzalcoatlus sp, an animal just half as big as the giant species. It is also known from much better fossil remains.





Despite being featured prominently in popular culture, it is very poorly known. Fossils of Q. northropi have always been scarce. So it has to be reconstructed on the basis of its close relatives. The skull of this species for example, is unknown and instead the head of the contemporary Q. sp. is used in reconstructions. This results in a creature which is a combination of two species.





Often the animal we see in illustrations is just a scaled-up version of the smaller species. But the larger size of Q. northropi instantly results in it being the more popular animal and the most represented azhdarchid in popular culture.





References

Habib, M. B. and Witton, M. P., 2010, Soaring efficiency and long distance travel in giant pterosaurs. Acta Geoscientica Sinica, 31 (1), 27-28

Witton, M. P., 2007, Titans of the skies: azhdarchid pterosaurs. Geology Today 23, 33-38.

Witton M. P., Habib M. B., 2010, On the Size and Flight Diversity of Giant Pterosaurs, the Use of Birds as Pterosaur Analogues and Comments on Pterosaur Flightlessness. PLoS ONE 5(11): e13982

Witton, M. P. and Habib, M. B., 2010, The volancy, or not, of giant pterosaurs. Acta Geoscientica Sinica, 31 (1), 76-78.

Witton M. P., Naish D., 2008, A Reappraisal of Azhdarchid Pterosaur Functional Morphology and Paleoecology. PLoS ONE 3(5): e2271