Editing Diprotodon (section)

===Size===
[[File:Guide to fossil mammals and birds (1896) Diprotodon australis.png|thumb|1896 illustration of a ''Diprotodon'' and human skull]]

''Diprotodon'' is the largest-known marsupial to ever have lived.<ref name=Price2009/> In life, adult ''Diprotodon'' could have reached {{cvt|160–180|cm|ftin}} at the shoulders and {{cvt|275–340|cm|ft|0}} from head to tail.{{sfn|Vickers-Rich|1991|loc=[https://www.biodiversitylibrary.org/item/123394#page/1118/mode/1up p. 1102]}} Accounting for cartilaginous [[intervertebral disc]]s, ''Diprotodon'' may have been 20% longer than reconstructed skeletons, exceeding {{cvt|400|cm|ftin}}.<ref name = "Wroe2003">{{cite journal| last1 = Wroe | first1 = S. | last2 = Crowther | first2 = M.| last3 = Dortch | first3 = J. | last4 = Chong | first4 = J.| year=2004| title = The size of the largest marsupial and why it matters| journal = Proceedings of the Royal Society B: Biological Sciences| volume = 271 | issue = Suppl 3 | pages = S34–S36| pmc = 1810005 | pmid=15101412| doi = 10.1098/rsbl.2003.0095}}</ref>

As researchers were formulating predictive body-mass equations for fossil species, efforts were largely constrained to [[eutherian]] mammals rather than marsupials.<ref name = "Wroe2003"/> The first person to attempt to estimate the living weight of ''Diprotodon'' was Peter Murray in his 1991 review of the megafauna of Pleistocene Australia; Murray made an estimate of {{cvt|1150|kg}} using cranial and dental measurements, which he said was probably not a very precise figure.{{sfn|Vickers-Rich|1991|loc=p. 1156}} This made ''Diprotodon'' the largest herbivore in Australia. In 2001, Canadian biologist Gary Burness and colleagues did a [[linear regression]] between the largest herbivores and carnivores—living or extinct—from every continent (for Australia: ''Diprotodon'', ''[[Varanus priscus]]'', and ''[[Thylacoleo|Thylacoleo carnifex]]'') against the landmass area of their continent, and another regression between the daily food intake of living creatures against the landmass of their continents. He calculated the food requirement of ''Diprotodon'' was 50–60% smaller than expected for Australia's landmass, which he believed was a result of a generally lower metabolism in marsupials compared to placentals—up to 20% lower—and sparser nutritious vegetation than other continents. The maximum-attainable body size is capped much lower than those for other continents.<ref>{{cite journal|first1=G. P.|last1=Burness|first2=J.|last2=Diamond|author2-link=Jared Diamond|first3=T.|last3=Flannery|year=2001|title=Dinosaurs, dragons, and dwarfs: The evolution of maximal body size|journal=Proceedings of the National Academy of Sciences|volume=98|issue=25|pages=14518–14523
|doi=10.1073/pnas.251548698|pmid=11724953 |pmc=64714 |bibcode=2001PNAS...9814518B |doi-access=free }}</ref>

In 2003, Australian palaeontologist Stephen Wroe and colleagues took a more-sophisticated approach to body mass than Murray's estimate. They made a regression between the minimum circumference of the femora and humeri of 18 quadrupedal marsupials and 32 placentals against body mass, and then inputted 17 ''Diprotodon'' long bones into their predictive model. The results ranged from {{cvt|2,272–3,417|kg}}, for a mean of {{cvt|2,786|kg}}, though Wroe said reconstructing the weight of extinct creatures that far outweighed living counterparts{{efn|A bull [[red kangaroo]], the largest living marsupial, can weigh {{cvt|22–85|kg}}.<ref>{{cite web|title=Largest living marsupial|publisher=Guinness Book of World Records|access-date=31 August 2022|url=https://www.guinnessworldrecords.com/world-records/504773-largest-marsupial-living}}</ref>}} is problematic. For comparison, an [[American bison]] they used in their study weighed {{cvt|1179|kg}} and a hippo weighed {{cvt|1950|kg}}.<ref name = "Wroe2003"/>