Editing Diprotodon (section)

===Diet===
[[File:Diprotodon sculpture.jpg|thumb|''Diprotodon'' sculpture at the [[Australian Museum]]]]

Like modern megaherbivores, most evidently the [[African elephant]], Pleistocene Australian megafauna likely had a profound effect on the vegetation, limiting the spread of forest cover and woody plants.<ref>{{cite journal|first1=E. S.|last1=Bakker|first2=J. L.|last2=Gill|first3=C. N.|last3=Johnson|first4=F. W. M.|last4=Vera|first5=C. J.|last5=Sandom|first6=G. P.|last6=Asner|first7=J.-C.|last7=Svenning|year=2015|title=Combining paleo-data and modern exclosure experiments to assess the impact of megafauna extinctions on woody vegetation|journal=Proceedings of the National Academy of Sciences|volume=113|issue=4|pages=847–855|doi=10.1073/pnas.1502545112|pmid=26504223 |pmc=4743795 |doi-access=free }}</ref> [[Isotopes of carbon#Tracing food sources and diets|Carbon isotope analysis]] suggests ''Diprotodon'' fed on a broad range of foods and, like kangaroos, was consuming both [[C3 carbon fixation|C<sub>3</sub>]]—well-watered trees, shrubs, and grasses—and [[C4 carbon fixation|C<sub>4</sub>]] plants—arid grasses,<ref>{{cite journal|url=https://www.academia.edu/1099030|first=D. R.|last=Gröke|year=1997|title=Distribution of C3 and C4 plants in the Late Pleistocene of South Australia recorded by isotope biogeochemistry of collagen in megafauna|journal=Australian Journal of Botany|volume=45|issue=3|pages=607–617|doi=10.1071/BT96040|bibcode=1997AuJB...45..607G }}</ref> a finding replicated by calcium isotope analysis showing ''Diprotodon'' to have been a mixed feeder.<ref>{{Cite journal |last1=Koutamanis |first1=Dafne |last2=McCurry |first2=Matthew |last3=Tacail |first3=Theo |last4=Dosseto |first4=Anthony |date=22 November 2023 |title=Reconstructing Pleistocene Australian herbivore megafauna diet using calcium and strontium isotopes |journal=[[Royal Society Open Science]] |language=en |volume=10 |issue=11 |doi=10.1098/rsos.230991 |issn=2054-5703 |pmc=10663789 |pmid=38026016 |bibcode=2023RSOS...1030991K }}</ref> Carbon isotope analyses on ''Diprotodon'' excavated from the [[Cuddie Springs]] site in [[unit (geology)|unit]]s SU6 (possibly 45,000 years old) and SU9 (350,000 to 570,000 years old) indicate ''Diprotodon'' adopted a somewhat-more-varied seasonal diet as Australia's climate dried but any change was subtle. In contrast, contemporary kangaroos and wombats underwent major dietary shifts or specialisations towards, respectively, C<sub>3</sub> and C<sub>4</sub> plants.<ref>{{cite journal|first1=L. R. G.|last1=DeSantis|first2=J. H.|last2=Field|first3=S.|last3=Wroe|first4=J. R.|last4=Dodson|year=2017|title=Dietary responses of Sahul (Pleistocene Australia–New Guinea) megafauna to climate and environmental change|journal=Paleobiology|volume=43|issue=2|page=190|doi=10.1017/pab.2016.50|s2cid=13134989 |doi-access=free|bibcode=2017Pbio...43..181D }}</ref> The fossilised, incompletely digested gut contents of one 53,000-year-old individual from [[Lake Callabonna]] show its last meal consisted of young leaves, stalks, and twigs.<ref name=Gillespie2008>{{cite journal|last1=Gillespie|first1=R.|last2=Fifield|first2=L. K.|last3=Levchenko |first3=V.|last4=Wells|first4=R.|year=2008|title=New <sup>14</sup>C Ages on Cellulose from Diprotodon Gut Contents: Explorations in Oxidation Chemistry and Combustion|journal=Radiocarbon|volume=50|issue=1|pages=75–81|doi=10.1017/s003382220004337x|s2cid=54577642 |doi-access=free|bibcode=2008Radcb..50...75G }}</ref>

The molars of ''Diprotodon'' are a simple bilophodont shape. Kangaroos use their bilophodont teeth to grind tender, low-fibre plants as a [[browsing (herbivory)|browser]] as well as grass as a grazer. Kangaroos that predominantly graze have specialised molars to resist the abrasiveness of grass but such adaptations are not exhibited in ''Diprotodon'', which may have had a mixed diet similar to that of a browsing [[wallaby]]. It may also have chewed like wallabies, beginning with a vertical crunch before grinding transversely, as opposed to wombats, which only grind transversely. Similarly to many large [[ungulate]]s (hoofed mammals), the jaws of ''Diprotodon'' were better suited for crushing rather than grinding, which would have permitted it to process vegetation in bulk.<ref name=Sharp2014/>

In 2016, Australian biologists Alana Sharpe and Thomas Rich estimated the maximum-possible [[bite force]] of ''Diprotodon'' using [[finite element analysis]]. They calculated {{cvt|2374|N}} at the incisors and {{cvt|4118|to|11134|N}} across the molar series.<ref name=Sharpe2016/> For reference, the [[American alligator]] can produce forces upwards of {{cvt|9500|N}}.<ref>{{cite journal|first1=G. M.|last1=Erickson|first2=A. K.|last2=Lappin|first3=K.|last3=Vliet|year=2003|title=The ontogeny of bite-force performance in American alligator (''Alligator mississippiensis'')|journal=Journal of Zoology|volume=260|issue=6|pages=317–327|doi=10.1017/S0952836903003819}}</ref> Though these are likely overestimates,{{efn|[[Finite element analysis]] considers the skull's [[section modulus]]—an object's ability to resist bending—but the material properties of marsupial skulls are not well studied. Sharpe and Rich used what they considered a typical [[Young's modulus]] and [[Poisson's ratio]] for a mammalian skull—respectively {{cvt|20|GPa}} and 0.3—and unsafely assumed these properties were uniform across the entire skull. This likely would have made their model skull stiffer than the real thing.<ref name=Sharpe2016/>}} the jaws of ''Diprotodon'' were exceptionally strong, which would have allowed it to consume a broad range of plants, including tough, fibrous grasses.<ref name=Sharpe2016/>