Editing Quetzalcoatlus (section)

===Size===
{{See also|Pterosaur size}}
[[File:Quetzalcoatlus Size Comparison.svg|thumb|left|Size comparison of a human to ''Q. lawsoni'' (red) and ''Q. northropi'' (orange)]]
''Quetzalcoatlus'' is regarded as one of the [[Pterosaur size|largest pterosaurs]],<ref name="wittonweight2010" /> though its exact size has been difficult to determine. In 1975, Douglas Lawson compared the wing bones of ''Q. northropi'' to equivalent elements in ''[[Dsungaripterus]]'' and ''[[Pteranodon]]'' and suggested that it represented an individual with a wingspan of around {{cvt|15.5|m}}, or, alternatively, {{Convert|11|m|abbr=on}} or {{Convert|21|m|abbr=on}}.<ref name="lawson1975" /> Estimates put forward in subsequent years varied dramatically, ranging from {{Convert|5.2–25.8|m|ft|abbr=on}}, owing to differences in methodology.<ref name="andres2021" /> Among the supporters of the initial size estimates was [[Robert T. Bakker]], who, in his 1988 book ''[[The Dinosaur Heresies]]'', contended that ''Quetzalcoatlus'' may indeed have reached the upper estimates, and that it may have remained flighted by altering its method of flapping.<ref>{{Cite book |last=Bakker |first=Robert T. |author-link=Robert T. Bakker |title=The Dinosaur Heresies: new theories unlocking the mystery of the dinosaurs and their extinction |date=1986 |publisher=Morrow |isbn=978-0-688-04287-5 |edition=6.print. |location=New York}}</ref> Other estimates contemporary to Bakker's, however, consistently supported a smaller size of {{cvt|11|–|12|m}}.<ref name="andres2021" /> More recent estimates based on greater knowledge of azhdarchid proportions place its wingspan at {{cvt|10|–|11|m}}.<ref name="padian2021" /><ref name="Paul-2022" /><ref name="witton2010"/> This would approach the maximum size possible for azhdarchids, estimated at {{cvt|12|–|13|m}};<ref name=":1" /> while higher wingspans may technically be possible, they would require significant morphological changes,<ref name=":1" /> and the animal would struggle to become airborne due to increased strain on its joints and [[long bone]]s.<ref name=":7" /> In one paper from the 2021 Memoir which redescribed ''Quetzalcoatlus'', ''Q. lawsoni'' was estimated to have a wingspan of around {{Convert|4.5|m|ft|abbr=on}}.<ref name="andres2021" /> In 2022, [[Gregory S. Paul]] suggested that it had a somewhat larger wingspan of around {{cvt|5|m|ft}} and a body length, from beak to tail, of {{cvt|3.5|m|ft}}.<ref name="Paul-2022" /> Large azhdarchids such as ''Q. northropi'' have been estimated to have a shoulder height of about {{cvt|2–3|m|ft}},<ref>{{Cite journal |last=Witton |first=Mark P. |date=2008 |title=A new approach to determining pterosaur body mass and its implications for pterosaur flight |url=https://epub.ub.uni-muenchen.de/id/eprint/12010 |journal=Zitteliana |pages=143–158 |language=en |doi=10.5282/UBM/EPUB.12010}}</ref><ref name=":7">{{Cite journal |last=Witton |first=Mark P. |date=2010 |title=Pteranodon and beyond: the history of giant pterosaurs from 1870 onwards |url=https://www.lyellcollection.org/doi/10.1144/SP343.19 |journal=Geological Society, London, Special Publications |language=en |volume=343 |issue=1 |pages=313–323 |doi=10.1144/SP343.19 |bibcode=2010GSLSP.343..313W |issn=0305-8719}}</ref> and the head may have been held at a similar height to that of an extant giraffe.<ref name=":1" />

Body mass estimates for ''Quetzalcoatlus'' have, similarly, been historically variable. Mass estimates for giant azhdarchids are problematic because no existing species shares a similar size or body plan, and in consequence, published results vary widely.<ref name="witton&naish2008">{{cite journal|last1=Witton|first1=Mark P.|last2=Naish|first2=Darren|title=A Reappraisal of azhdarchid pterosaur functional morphology and paleoecology|journal=PLOS ONE|year=2008|volume=3|issue=5|page=e2271|doi=10.1371/journal.pone.0002271|pmid=18509539|pmc=2386974|doi-access=free|bibcode=2008PLoSO...3.2271W}}</ref> [[Crawford Greenewalt]] gave mass estimates of between {{Convert|30–440|kg|abbr=on}} for ''Q. northropi'', with the former figure assuming a small wingspan of {{Convert|5.2|m|abbr=on}}, and the latter assuming a far larger wingspan of {{Convert|15.4|m|abbr=on}}.<ref name="lawson1975b" /> In 2010, Donald M. Henderson recovered the body mass of ''Quetzalcoatlus'' at {{cvt|544|kg}}, twice that of other contemporary estimates, citing it as evidence for [[wikt:flightless|secondary flightlessness]] in the genus.<ref name="henderson2010" /> However, the vast majority of estimates published since the 2000s have hovered around {{cvt|200|-|250|kg}},<ref name="Paul2002">{{cite book |last=Paul |first=Gregory S. |url=https://archive.org/details/dinosaursofairev0000paul |title=Dinosaurs of the Air: The Evolution and Loss of Flight in Dinosaurs and Birds |publisher=Johns Hopkins University Press |year=2002 |isbn=0-8018-6763-0 |page=472 |url-access=registration}}</ref><ref name="wittonweight2010" /> due largely to a greater understanding of how aberrant the anatomy of azhdarchids was in comparison to other pterosaur clades.<ref name=":1" /> In 2021, Kevin Padian and colleagues estimated that ''Q. northropi'' would have weighed around {{cvt|150|kg|lb}}, and that ''Q. lawsoni'' would have weighed {{cvt|20|kg|lb}},<ref name="padian2021">{{cite journal|last1=Padian|first1=K.|last2=Cunningham|first2=J.R.|last3=Langston|first3=W. Jr.|last4=Conway|first4=J.|year=2021|title=Functional morphology of ''Quetzalcoatlus'' Lawson 1975 (Pterodactyloidea: Azhdarchoidea)|journal=Journal of Vertebrate Paleontology|volume=41|issue=sup1|pages=218–251|bibcode=2021JVPal..41S.218P|doi=10.1080/02724634.2020.1780247|s2cid=245125427|doi-access=free}}</ref> while a year later, Gregory S. Paul estimated a body mass of {{cvt|65|kg|lbs}} for the latter species.<ref name="Paul-2022">{{Cite book|last=Paul|first=Gregory S.|title=The Princeton Field Guide to Pterosaurs|year=2022|publisher=Princeton University Press|pages=161–162|doi=10.1515/9780691232218|isbn=9780691232218|s2cid=249332375}}</ref>