Editing Quetzalcoatlus (section)

===Flight===
[[File:Quetzalcoatlus07.jpg|left|thumb|Restoration of a ''Quetzalcoatlus'' in flight]]
The nature of flight in ''Quetzalcoatlus'' and other giant azhdarchids was poorly understood until serious biomechanical studies were conducted in the 21st century. A 1984 experiment by [[Paul MacCready]] used practical aerodynamics to test the flight of ''Quetzalcoatlus''. MacCready constructed a model flying machine or, [[ornithopter]], with a simple computer functioning as an [[autopilot]]. The model successfully flew with a combination of soaring and wing flapping.<ref name="maccready1985">{{cite journal |last=MacCready |first=P. |year=1985 |title=The Great Pterodactyl Project |url=http://calteches.library.caltech.edu/596/02/MacCready.pdf |journal=Engineering & Science |volume=49 |pages=18–24 |number=2}}</ref> The model was based on a then-current weight estimate of around {{cvt|80|kg}}, far lower than more modern estimates of over {{cvt|200|kg}}.<ref name="henderson2010">{{cite journal|last1=Henderson|first1=Donald M.|s2cid=85679231|title=Pterosaur body mass estimates from three-dimensional mathematical slicing|journal=Journal of Vertebrate Paleontology|year=2010|volume=30|issue=3|pages=768–785|doi=10.1080/02724631003758334|bibcode=2010JVPal..30..768H|url=http://doc.rero.ch/record/32754/files/PAL_E3629.pdf}}</ref> The method of flight in these pterosaurs depends largely on their weight, which has been controversial, and widely differing masses have been favored by different scientists. Some researchers have suggested that these animals employed slow, [[Lift (soaring)|soaring]] flight, while others have concluded that their flight was fast and dynamic.<ref name="witton&naish2008" /> In 2010, Donald Henderson argued that the mass of ''Q. northropi'' had been underestimated, even the highest estimates, and that it was too massive to have achieved powered flight. He estimated it in his 2010 paper as {{cvt|540|kg}}, and argued that it may have been [[Flightless bird|flightless]].<ref name="henderson2010" />

[[File:QuetzalcoatlusROM.JPG|thumb|right|''Quetzalcoatlus'' skeleton mounted in a flying pose at the [[Royal Ontario Museum]].]]

Other flight capability estimates have disagreed with Henderson's research, suggesting instead an animal superbly adapted to long-range, extended flight. In 2010, Mike Habib, a professor of biomechanics at [[Chatham University]], and Mark Witton, a British paleontologist, undertook further investigation into the claims of flightlessness in large pterosaurs. After factoring wingspan, body weight, and aerodynamics, computer modeling led the two researchers to conclude that ''Q. northropi'' was capable of flight up to {{cvt|80|mph|order=flip}} for 7 to 10 days at altitudes of {{cvt|15000|ft|order=flip}}. Habib further suggested a maximum flight range of {{cvt|8,000|–|12,000|mi|order=flip}} for ''Q. northropi''.<ref name="npr2010">{{cite web|last=Frazier|first=Reid|title=Peerless pterosaur could fly long-distance for days|url=https://www.npr.org/2010/11/16/131362653/peerless-pterosaur-could-fly-long-distance-for-days|work=[[Morning Edition]]|publisher=NPR|date=November 22, 2010|access-date=November 1, 2017}}</ref> Henderson's work was also further criticized by Witton and Habib in another study, which pointed out that, although Henderson used excellent mass estimations, they were based on outdated pterosaur models, which caused Henderson's mass estimations to be more than double what Habib used in his estimations and that anatomical study of ''Q. northropi'' and other big pterosaur forelimbs showed a higher degree of robustness than would be expected if they were purely quadrupedal.<ref name="wittonweight2010"/> This study proposed that large pterosaurs most likely utilized a short burst of powered flight to then transition to [[Lift (soaring)|thermal soaring]].<ref name="padian1983"/> However, a study from 2022 suggests that they would only have flown occasionally and for short distances, like the [[Kori bustard]] (the world's heaviest bird that actively flies) and that they were not able to soar at all.<ref>{{cite journal|last1=Goto|first1=Yusuke|last2=Yoda|first2=Ken|last3=Weimerskirch|first3=Henri|last4=Sato|first4=Katsufumi|title=How did extinct giant birds and pterosaurs fly? A comprehensive modeling approach to evaluate soaring performance|journal=PNAS Nexus|date=May 2, 2022|volume=1|issue=1|pages=pgac023|doi=10.1093/pnasnexus/pgac023|pmid=36712794|pmc=9802081}}</ref> Studies of ''Q. northropi'' and ''Q. lawsoni'' published in 2021 by Kevin Padian et al. instead suggested that ''Quetzalcoatlus'' was a very powerful flier. While Padian himself also suggested that the legs and feet were likely tucked under the body during flight as in modern birds, co-authors [[John Conway (palaeoartist)|John Conway]] and James Cunningham endorsed a system more in line with conventional models of pterosaur flight, wherein the hind limbs were splayed out while the animal was airborne.<ref name="padian2021" />