Quetzalcoatlus (named for the Aztec feathered serpent god Quetzalcoatl) was a pterodactyloid pterosaur known from the Late Cretaceous of North America (Campanian–Maastrichtian stages, 84–65 ma), and one of the largest known flying animals of all time. It was a member of the Azhdarchidae, a family of advanced toothless pterosaurs with unusually long, stiffened necks.
Discovery and species
Skull reconstruction of Quetzalcoatlus sp.
The first Quetzalcoatlus fossils were discovered in Texas (from the Javelina Formation at Big Bend National Park) in 1971 by Douglas A. Lawson. The specimen (numbered TMM 41450-41453) consisted of a partial wing (made up of the forearms and elongated 4th finger in pterosaurs), from an individual later estimated at over to 10 m (33 ft) in wingspan.[1] Lawson assigned the specimen to a new genus and species, Quetzalcoatlus northropi. [2] A second, yet-unnamed species from Texas was reported by Kellner and Langston in 1996.[3] The specimen (known provisionally as Q. sp.) is more complete than Q. northropi, and includes a partial skull, though it is much smaller, with an estimated wingspan of 5.5 meters (18 ft).[4]
An azhdarchid neck vertebrae, discovered in 2002 from the Hell Creek Formation, may also belong to Quetzalcoatlus. The specimen (BMR P2002.2) was recovered accidentally when it was included in a field jacket prepared to transport part of a tyrannosaur specimen. Despite this association with the remains of a large carnivorous dinosaur, it shows no evidence that it was fed on by the dinosaur. The bone came from an individual pterosaur estimated to have had a wingspan of 5 - 5.5m (16.5 - 18 ft).[5]
Paleobiology
Life restoration of a group of Quetzalcoatlus northropi.
There are a number of different ideas about the lifestyle of Quetzalcoatlus. With its long neck vertebrae and long toothless jaws it might have fed on fish like a heron, or perhaps it scavenged like the Marabou Stork. Others maintain that it fed like modern-day skimmers. Presumably Quetzalcoatlus could take off under its own power, but once aloft it may have spent much of its time soaring. On the ground, Quetzalcoatlus probably walked on all fours. Recent studies suggest that it may have hunted on the ground like a modern stork, using flight as a method of long-range transport.[1]
Size comparison of the two known Quetzalcoatlus species and a human.
There have been suggestions that the largest Quetzalcoatlus specimens represent an upper biological limit for flight.citation needed The largest remains indicate an individual with a wingspan as large as 12 m (40 ft), though more recent estimates based on greater knowledge of azhdarchid proportions place its wingspan at 10-11 meters (33-36 ft). However, similar claims to an upper size limit for flight accompanied the discovery of large (up to 9 m (30 ft)) Pteranodon, and azhdarchids larger than Quetzalcoatlus with wingspans 12 meters or more (such as Hatzegopteryx) have been discovered.[6]
During the Cretaceous period, Texas' climate was similar to modern tropical coastal wetlands and lagoons, extending along the Cretaceous Seaway that filled the center of North America. Bones of related animals are also known from Dinosaur Provincial Park, Alberta, Canada.
Along with the dinosaurs, Quetzalcoatlus became extinct at the end of the Cretaceous period.
In popular culture
There is a fictional species of Quetzalcoatlus known as Skybax in the Dinotopia series. It is also featured in the nature documentary Walking with Dinosaurs episode "Death of a Dynasty", 3rd episode of Dinosaur Planet, and When Dinosaurs Roamed America, episode 5 (Late Cretaceous).
References
- ^ a b Witton, M.P., and Naish, D. (2008). "A Reappraisal of Azhdarchid Pterosaur Functional Morphology and Paleoecology." PLoS ONE, 3(5): e2271. doi:10.1371/journal.pone.0002271Full text online
- ^ Lawson, D. A. (1975). "Pterosaur from the Latest Cretaceous of West Texas. Discovery of the Largest Flying Creature." Science, 187: 947-948.
- ^ Kellner, A.W.A., and Langston, W. (1996). "Cranial remains of Quetzalcoatlus (Pterosauria, Azhdarchidae) from Late Cretaceous sediments of Big Bend National Park, Texas." Journal of Vertebrate Paleontology, 16: 222–231.
- ^ Buffetaut, E., Grigorescu, D., and Csiki, Z. (2002). "A new giant pterosaur with a robust skull from the latest Cretaceous of Romania." Naturwissenschaften, 89: 180–184.
- ^ Henderson, M.D. and Peterson, J.E. "An azhdarchid pterosaur cervical vertebra from the Hell Creek Formation (Maastrichtian) of southeastern Montana." Journal of Vertebrate Paleontology, 26(1): 192–195.
- ^ Buffetaut, E., Grigorescu, D., and Csiki, Z. (2002). "A new giant pterosaur with a robust skull from the latest Cretaceous of Romania." Naturwissenschaften, 89(4): 180-184. Abstract
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