Quetzalcoatlus Essay

Quetzalcoatlus northropi is an azhdarchid pterosaur known from the Late Cretaceous of North America 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. The Quetzalcoatlus was first discovered in Texas in 1971 by geology graduate student Douglas A. Lawson. The feeding habits of Quetzalcoatlus are controversial. Originally, it was assumed to catch fish and crustaceans, like most other pterosaurs, until it was realized that it lived 248 miles from any shore during the Cretaceous period, and that there was no evidence for an inland water source for miles around. Lawson, in 1975, rejected the fish eating hypothesis and said that it instead was a scavenger, like the marabou stork, feeding on the
carcasses of sauropods and other dead dinosaurs. Studies have shown that Quetzalcoatlus could take off under its own power, but once aloft it may have spent much of its time soaring. To test the flight on Quetzalcoatlus, a program sponsored by Johnson Wax involved the construction of a model flying machine. It was about half scale (20 ft), the size of Quetzalcoatlus sp., and had a simple computer functioning as an autopilot. The experiment worked and the model flew through the skies with a combination of soaring and wing flapping. The model is now resting in the Smithsonian Institution Air and Space Museum. The specimen consisted of a partial wing (made up of the forearms and elongated fourth finger in pterosaurs), from an individual later estimated at over to 10 m (33 ft) in wingspan. Lawson discovered a second site of the same age, about forty kilometer from the first, where between 1972 and 1974 he and Professor Winn Langston Jr. of the Texas Memorial Museum unearthed three fragmentary skeletons of much smaller individuals. Lawson in 1975 announced the find in an article in Science. That same year, in a subsequent letter to the same journal he made the original large specimen, TMM 41450-3, the holotype of a new genus and species, Quetzalcoatlus northropi. The genus name refers to the Aztec "feathered serpent" god Quetzalcoatl. The specific name honors John Knudsen Northrop, the founder of Northrop, who was interested in large tailless aircraft designs resembling Quetzalcoatlus. At first it was assumed that the smaller specimens were juvenile or subadult forms of the larger type.
Later, when more remains were found, it was realized they could have been a separate species. This possible second species from Texas was provisionally referred to as a Quetzalcoatlus sp. by Alexander Kellner and Langston in 1996, indicating that its status was too uncertain to give it a full new species name. The smaller specimens are more complete than the Q. northropi holotype, and include four partial skulls, though they are much less massive, with an estimated wingspan of 5.5 meters (18 ft). Quetzalcoatlus northropi is the largest known animal to have ever been able to fly. When it was first discovered, scientists estimated that the fossil came from a pterosaur with a wingspan of up to 45 feet (13.7m), choosing the middle between three extrapolations from the proportions of other pterosaurs that gave an estimate of 40, 50 and 70 feet respectively. in 1981, futher study showed that this estimate was too large, and lowered the estimated wingspan to 50 feet (15m). More recently, the wingspan estimated has been reduced yet again, this time to 36 feet
(10.9m).