View source for Diprotodon

{{Short description|Extinct marsupial genus}}
{{good article}}
{{Use dmy dates|date=May 2021}}
{{Use Australian English|date=May 2023}}
{{Automatic taxobox
| fossil_range = [[Pleistocene]], {{geological range|1.77/0.78|0.04}}
| image = Diprotodon australis skeleton 1.JPG
| image_caption = ''Diprotodon'' skeleton cast, [[Gallery of Paleontology and Comparative Anatomy|MNHN]], Paris
| image2 = Diprotodon (Diprotodon optatum).png
| image2_caption = Illustration of a female ''Diprotodon'' with joey and [[sulphur-crested cockatoo]]
| taxon = Diprotodon
| authority =
| type_species = '''''Diprotodon optatum'''''
| type_species_authority = [[Richard Owen|Owen]], 1838
| synonyms =
*''D.&nbsp;australis'' {{small|Owen, 1844}}
*''D.&nbsp;annextans'' {{small|McCoy, 1861}}
*''D.&nbsp;minor'' {{small|Huxley, 1862}}
*''D.&nbsp;longiceps'' {{small|McCoy, 1865}}
*''D.&nbsp;bennettii'' {{small|Krefft, 1873}}
*''D.&nbsp;loderi'' {{small|Krefft, 1873}}
*''D.&nbsp;optatus'' {{small|Woods, 1960}}
*''D.&nbsp;australe'' {{small|Molnar & Kurz, 1997}}
| synonyms_ref = <ref name=Price2008/>
}}

'''''Diprotodon''''', from [[Ancient Greek]] [[wikt:δί-|δί-]] (''dí-''), meaning "two", [[wikt:πρῶτος|πρῶτος]] (''prôtos''), meaning "first", and [[wikt:ὀδούς|ὀδούς]] (''odoús''), meaning "tooth", is an extinct [[genus]] of [[Diprotodontidae|diprotodontid]] [[marsupial]] from the [[Pleistocene]] of Australia containing one [[species]], '''''D. optatum'''''. The earliest finds date to 1.77 million to 780,000 years ago, but most specimens are dated to after 110,000 years ago. Its remains were first unearthed in 1830, in [[Wellington Caves]], [[New South Wales]], and contemporary paleontologists guessed they belonged to [[rhino]]s, [[elephant]]s, [[hippo]]s or [[dugong]]s.

''Diprotodon'' was formally [[species description|described]] by English naturalist [[Richard Owen]] in 1838, and was the first named Australian fossil mammal. This led Owen to become the foremost authority of his time on other marsupials and [[Australian megafauna]], which were enigmatic to European science.

''Diprotodon'' is the largest-known marsupial to have ever lived; it greatly exceeds the size of its closest living relatives [[wombat]]s and [[koala]]s. It is a member of the extinct family [[Diprotodontidae]], which includes other large quadruped herbivores. It grew to {{cvt|1.8|m}} at the shoulders, over {{cvt|4|m}} from head to tail, and likely weighed several tonnes, possibly as much as {{cvt|3500|kg}}. Females were smaller than males. ''Diprotodon'' supported itself on elephant-like legs to travel long distances, and inhabited most of Australia. The digits were weak; most of the weight was probably borne on the wrists and ankles. The hindpaws angled inward at 130°. Its jaws may have produced a strong [[bite force]] of {{convert|2300|N|lk=in|abbr=off}} at the long and ever-growing [[incisor]] teeth, and over {{convert|11000|N}} at the last [[molar (tooth)|molar]]. Such powerful jaws would have allowed it to eat vegetation in bulk, crunching and grinding plant materials such as twigs, buds and leaves of woody plants with its [[bilophodont]] teeth.

It is the only marsupial and [[metatheria]]n that is known to have made seasonal migrations. Large herds, usually of females, seem to have marched through a wide range of habitats to find food and water, walking at around {{cvt|6|kph}}. ''Diprotodon'' may have formed [[polygyny in animals|polygynous]] societies, possibly using its powerful incisors to fight for mates or fend off predators, such as the largest-known marsupial carnivore ''[[Thylacoleo|Thylacoleo carnifex]]''. Being a marsupial, the mother may have raised her joey in a [[pouch (marsupial)|pouch]] on her belly. It’s pouch would have possibly faced backwards, as in wombats, to which it is related.

''Diprotodon'' went extinct about 40,000 years ago as part of the [[Late Pleistocene megafauna extinctions]], along with every other Australian mammal over {{cvt|100|kg}}. The extinction was possibly caused by extreme drought conditions and predation pressure from the first [[Aboriginal Australian]]s, who likely co-existed with ''Diprotodon'' and other megafauna in Australia for several thousand years prior to its extinction. There is little direct evidence of interactions between Aboriginal Australians and ''Diprotodon''—or most other Australian megafauna. ''Diprotodon'' has been thought by some authors to have been the origin of some [[Australian Aboriginal religion and mythology|aboriginal mythological figures]]—most notably the [[bunyip]]—and [[aboriginal rock art]]works, but these ideas are unconfirmed.

==Research history==
[[File:Evolution in the past (Plate 55) BHL21155651.jpg|thumb|left|Early reconstruction of ''Diprotodon'' by [[Alice B. Woodward]], 1912]]

In 1830, farmer George Ranken found a diverse fossil assemblage while exploring [[Wellington Caves]], [[New South Wales]], Australia.<ref>{{cite book|last=Long|first=G.|year=1967|chapter=Ranken, George (1793–1860)|title=Australian Dictionary of Biography|publisher=Australian National University|url=https://adb.anu.edu.au/biography/ranken-george-2572/text3515}}</ref> This was the first major site of extinct [[Australian megafauna]]. Remains of ''Diprotodon'' were excavated when Ranken later returned as part of a formal expedition that was headed by explorer Major [[Thomas Mitchell (explorer)|Thomas Mitchell]].<ref name="Holden"/>

At the time these massive fossils were discovered, it was generally thought they were remains of rhinos, elephants, hippos, or dugongs. The fossils were not formally described until Mitchell took them in 1837 to his former colleague English naturalist [[Richard Owen]] while in England publishing his journal.<ref name="Holden">{{cite book|last1=Holden |first1=R.|last2=Holden |first2=N.|year=2001|chapter=Bones of contention: monster skeletons and bunyip skulls|title=Bunyips: Australia's folklore of fear|publisher=National Library Australia|isbn=978-0-642-10732-9|chapter-url=https://books.google.com/books?id=UnKPCZT0x6kC&pg=PA86}}</ref> In 1838, while studying a piece of a right [[mandible]] with an [[incisor]], Owen compared the tooth to those of wombats and hippos; he wrote to Mitchell designating it as a new genus ''Diprotodon''. Mitchell published the correspondence in his journal.<ref>{{cite book|last=Owen|first=R.|year=1838|editor-last=Mitchell|editor-first=T. L.|title=Three expeditions into the interior of Eastern Australia, with descriptions of the recently explored region of Australia Felix, and of the present colony of New South Wales|publisher=T. and W. Boone|volume=2|pages=362–363|url=https://gutenberg.net.au/ebooks/e00036.html#mitchell2-48}}</ref> Owen formally described ''Diprotodon'' in Volume 2 without mentioning a species; in Volume 1, however, he listed the name ''Diprotodon optatum'', making that the [[type species]].{{sfn|Mahoney|1975|loc=p. 67}}

''Diprotodon'' means "two protruding front teeth" in [[Ancient Greek]]<ref name="Holden"/> and ''optatum'' is [[Latin]] for "desire" or "wish".<ref>{{cite web|url=https://www.latin-english.com/latin/optatum/|title=Details for ''optatum'', ''optati''|website=latin-english.com|access-date=19 February 2023}}</ref> It was the first-ever Australian fossil mammal to be described.{{efn|Owen, and other naturalists of the time would use ''Diprotodon'', and the other unusual extinct creatures of Wellington Cave and the Australian continent to deconstruct [[progressive creationism|progressive creationist]] arguments. These claimed that God created certain forms to exist in certain environments and time periods, based on the fossils of modern animals such as hyenas – which are today found only in Africa – but were being unearthed in every other continent. This was confounded by ''Diprotodon'' and more of Owen's taxa because they were found nowhere else, and more-typical animals were not found in Australia either, despite the Australian climate's similarity to that of Africa. Owen nonetheless disagreed with [[Charles Darwin]]'s theory of [[natural selection]].{{sfn|Vickers-Rich|1991|loc=p. 8}}}}<ref name="Holden"/> In 1844, Owen replaced the name ''D. optatum'' with "''D. australis''".<ref name=Owen1844>{{cite journal|url=https://www.biodiversitylibrary.org/item/71833#page/282/mode/1up|first=R.|last=Owen|author-link=Richard Owen|year=1844|title=Description of a Fossil Molar Tooth of a ''Mastodon'' discovered by Count Strzlecki in Australia|journal=Annals and Magazine of Natural History|volume=14|issue=91|page=268|doi=10.1080/037454809495170}}</ref> Owen only once used the name ''optatum'' and the acceptance of its apparent replacement "''australis''" has historically varied widely{{sfn|Mahoney|1975|loc=p. 67}} but ''optatum'' is now standard.<ref name=Price2008/>

In 1843, Mitchell was sent more ''Diprotodon'' fossils from the recently settled [[Darling Downs]] and relayed them to Owen. With these, Owen surmised that ''Diprotodon'' was an elephant related to or [[synonym (taxonomy)|synonymous]] with ''[[Mastodon]]'' or ''[[Deinotherium]]'', pointing to the incisors which he interpreted as tusks, the flattening (anteroposterior compression) of the femur similar to the condition in elephants and rhinos, and the raised ridges of the [[molar (tooth)|molar]] characteristic of elephant teeth. Later that year, he formally synonymised ''Diprotodon'' with ''Deinotherium'' as ''Dinotherium Australe'',<ref name=Owen1873>{{cite magazine |url=https://www.biodiversitylibrary.org/page/2326162#page/355/mode/1up|first=R.|last=Owen|author-link=Richard Owen|year=1843|title=Additional evidence proving the Australian ''Pachyderm'' described in a former number of the 'Annals' to be a ''Dinotherium'', with remarks on the nature and affinities of that genus |magazine=The Annals and Magazine of Natural History |volume=11 |issue=71 |pages=329–332}}</ref> which he recanted in 1844 after German naturalist [[Ludwig Leichhardt]] pointed out that the incisors clearly belong to a [[marsupial]].<ref name=Fensham2013>{{cite journal|first1=R. J.|last1=Fensham|first2=G. J.|last2=Price|year=2013|title=Ludwig Leichhardt and the significance of the extinct Australian megafauna|journal=Memoirs of the Queensland Museum|volume=7|issue=2|pages=621–632|url=https://www.researchgate.net/publication/256440954}}</ref> Owen still classified the molars from Wellington as ''Mastodon australis'' and continued to describe ''Diprotodon'' as likely elephantine.<ref name=Owen1844/>

In 1847, a nearly complete skull and skeleton was recovered from the Darling Downs, the latter confirming this elephantine characterisation.<ref name=Fensham2013/> The massive skeleton attracted a large audience while on public display in [[Sydney]].{{efn|The specimen was collected by R. B. Turner at [[Kings Creek, Queensland]], and was taken to Sydney in 1847 to be sold at auction. Leichhardt attempted to buy it for the new [[Australian Museum]] but Scottish entrepreneur [[Benjamin Boyd]] outbid him at £50. After being examined by Leichhardt, English geologist Reverend [[William Branwhite Clarke]], and curator [[William Sheridan Wall]], it was shipped to England but the ship was wrecked off the [[Sussex]] coast. Only the skull was saved; it was taken to Owen.<ref name=Fensham2013/>}} Leichhardt believed the animal was aquatic, and in 1844 he said it might still be alive in an undiscovered tropical area nearer the interior. But, as the [[European land exploration of Australia]] progressed, he became certain it was extinct.<ref>{{cite book|year=1976|chapter=Death of the Giants|title=Triumph of the Nomads: History of Ancient Australia|publisher=Springer|pages=51–52|isbn=978-1-349-02423-0}}</ref> Owen later become the foremost authority of Australian palaeontology of his time, mostly working with marsupials.{{sfn|Vickers-Rich|1991|loc=p. 8}}

[[File:Extinct monsters and creatures of other days (6288301841).jpg|thumb|Illustration of a ''Diprotodon'' fossil in the dry lakebed of [[Lake Callabonna]]]]

Huge assemblages of mostly-complete ''Diprotodon'' fossils have been unearthed in dry lakes and riverbeds.{{efn|The large assemblages of fossils in riverbeds are evidence that ''Diprotodon'' was a herding species.<ref name=Price2008/>}}<ref name=Price2008/> The largest known assemblage came from [[Lake Callabonna]], [[South Australia]].<ref name="Gillespie2008" /> Fossils were first noticed here by an aboriginal stockman working on a sheep property to the east. The owners, the Ragless brothers, notified the [[South Australian Museum]], which hired Australian geologist [[Henry Hurst (geologist)|Henry Hurst]], who reported an enormous wealth of fossil material and was paid £250 in 1893 to excavate the site. Hurst found up to 360 ''Diprotodon'' individuals over a few acres; excavation was restarted in the 1970s and more were uncovered. American palaeontologist [[Richard H. Tedford]] said multiple herds of these animals had at different times become stuck in mud while crossing bodies of water while water levels were low during [[dry season]]s.<ref>{{cite journal|url=https://media.australian.museum/media/dd/Uploads/Documents/36123/ams370_vXVII_11_lowres.4b289a9.pdf?_gl=1*5i3btn*_ga*MjQxOTU0ODIxLjE2NjAyNjIxNTg.*_ga_PZ3L84LQDF*MTY2MzAwNTUzNy4yLjAuMTY2MzAwNTUzNy42MC4wLjA.&_ga=2.52900264.1296749326.1663005538-241954821.1660262158|first=R. H.|last=Tedford|year=1973|title=The diprotodonts of Lake Callabonna|journal=Australian Natural History|volume=17|issue=11|pages=349–354}}</ref>

In addition to ''D. optatum'', several other species were erected in the 19th century, often from single specimens, on the basis of subtle anatomical variations.<ref name=Price2008/> Among the variations was size difference: adult ''Diprotodon'' specimens have two distinct size ranges. In their 1975 review of Australian fossil mammals, Australian palaeontologists J. A. Mahoney and [[William David Lindsay Ride]] did not ascribe this to [[sexual dimorphism]], because males and females of modern wombat and koala species—its closest living relatives—are skeletally indistinguishable,{{efn|Because joeys develop mostly outside the mother's womb, female marsupials do not require the adaptations to the skeleton that placentals need to survive gestation and childbirth, equating to few or no skeletal differences between males and females.<ref name=Price2008/> In modern wombats, the female can be slightly but insignificantly larger than the male.<ref>{{cite journal|first1=C. N.|last1=Johnson|first2=D. G.|last2=Crossman|year=1991|title=Sexual dimorphism in the northern hairy-nosed wombat, ''Lasiorhinus krefftii'' (Marsupialia: Vombatidae)|journal=Australian Mammalogy|volume=14|issue=2|pages=145–146|doi=10.1071/AM91019|s2cid=239233162 }}</ref> In koalas, males can be 50% larger than females.<ref>{{cite book|author=Jackson, S.|year=2003|title=Australian Mammals: Biology and Captive Management|publisher=CSIRO Publishing|page=147|isbn=978-0-643-06635-9}}</ref>}} so they assumed the same would have been true for extinct relatives, including ''Diprotodon''.{{sfn|Mahoney|1975|loc=p. 207}}

These other species are:
*''D. annextans'' was erected in 1861 by Irish palaeontologist [[Frederick McCoy]] based on some teeth and a partial mandible found near [[Colac, Victoria]]; the name may be a typo of ''annectens'', which means linking or joining, because he characterised the species as combining traits from ''Diprotodon'' and ''[[Nototherium]]'';{{sfn|Mahoney|1975|loc=pp. 85–86}}
*''D. minor'' was erected in 1862 by [[Thomas Huxley]] based on a partial [[palate]];<ref name=Huxley1862/>{{sfn|Mahoney|1975|loc=p. 104}} in 1991, Australian palaeontologist Peter Murray suggested classifying large specimens as ''D. optatum'' and smaller ones as "''D. minor''";<ref name=Price2008/>
*''D. longiceps'' was erected in 1865 by McCoy as a replacement for "''D. annextans''";{{sfn|Mahoney|1975|loc=p. 101}}
*''D. bennettii'' was erected in 1873 by German naturalist [[Gerard Krefft]] based on a nearly complete mandible collected by naturalists [[George Bennett (naturalist)|George Bennet]] and Georgina King near [[Gowrie, New South Wales]];{{sfn|Mahoney|1975|loc=pp. 88–89}} and
*''D. loderi'' was erected in 1873 by Krefft based on a partial [[palate]] collected by [[Andrew Loder]] near [[Murrurundi]], New South Wales.{{sfn|Mahoney|1975|loc=p. 101}}

In 2008, Australian palaeontologist Gilbert Price opted to recognise only one species ''D. optatum'' based most-notably on a lack of dental differences among these supposed species, and said it was likely ''Diprotodon'' was indeed sexually dimorphic, with the male probably being the larger form.<ref name=Price2008>{{cite journal |last= Price |first= G.J. |year= 2008 |title= Taxonomy and palaeobiology of the largest-ever marsupial, ''Diprotodon'' {{small|Owen, 1838}} (Diprotodontidae, Marsupialia) |journal=Zoological Journal of the Linnean Society |volume=153 |issue=2 |pages=369–397 |doi=10.1111/j.1096-3642.2008.00387.x |doi-access=free}}</ref>

==Classification==
===Phylogeny===
{{Multiple image
|total_width = 400
|image1 = Wombat 1.jpg
|image2 = Koala climbing tree.jpg
|footer = ''Diprotodon''{{'}}s closest living relatives are [[wombat]]s (left) and [[koala]]s (right)
}}

''Diprotodon'' is a marsupial in the [[order (biology)|order]] [[Diprotodontia]],{{efn|In 1868, Owen classified all marsupials (living or extinct) into either the [[order (biology)|orders]] [[Polyprotodontia]] (characterised by multiple pairs of [[mandible|mandibular]] [[incisor]]s) or [[Diprotodontia]] (a single pair of mandibular incisors). The name Diprotodontia does not derive from ''Diprotodon''.<ref>{{cite book|first=R.|last=Owen|author-link=Richard Owen|year=1868|title=On the anatomy of vertebrates|publisher=Longmans, Green|volume=3|page=293|url=https://www.biodiversitylibrary.org/item/78309#page/305/mode/1up|doi=10.5962/bhl.title.33654}}</ref> Marsupialia is divided into several orders, of which Diprotodontia is the largest.<ref>{{cite journal|last=Meredith|first=R. W. |author2=Westerman, M. |author3=Springer, M. S.|year=2009|title=A phylogeny of Diprotodontia (Marsupialia) based on sequences for five nuclear genes|journal=Molecular Phylogenetics and Evolution|volume=51|issue=3 |pages=554–571|url=http://www.montclair.edu/profilepages/media/5008/user/Meredith_et_al._2009_A_phylogeny_of_Diprotodontia_%28Marsupialia%29_based_on_sequences_for_five_nuclear_genes.pdf |archive-url=https://web.archive.org/web/20150518100116/http://www.montclair.edu/profilepages/media/5008/user/Meredith_et_al._2009_A_phylogeny_of_Diprotodontia_%28Marsupialia%29_based_on_sequences_for_five_nuclear_genes.pdf |archive-date=2015-05-18 |url-status=live|doi=10.1016/j.ympev.2009.02.009|pmid=19249373|bibcode=2009MolPE..51..554M }}</ref>}} [[suborder]] [[Vombatiformes]] (wombats and koalas), and [[infraorder]] Vombatomorphia (wombats and allies). It is unclear how different groups of vombatiformes are related to each other, because the best-known members (living or extinct) are exceptionally [[apomorphy and synapomorphy|derived]] (highly specialised forms that are quite different from their [[last common ancestor]]).<ref name=Beck2020/>

In 1872, American mammalogist [[Theodore Gill]] erected the [[superfamily (taxonomy)|superfamily]] Diprotodontoidea and [[family (biology)|family]] [[Diprotodontidae]] to house ''Diprotodon''.<ref>{{cite book|first=T.|last=Gill|author-link=Theodore Gill|year=1876|title=Arrangement of the families of mammals|series=Smithsonian miscellaneous collections|volume=11|issue=1|publisher=Smithsonian Institution|pages=25–26|doi=10.5962/bhl.title.14607|url=https://www.biodiversitylibrary.org/item/16824 }}</ref> New species were later added to both groups; by the 1960s, the first diprotodontoids dating to before the [[Pliocene]] were discovered, better clarifying their relationship to each other. Because of this, in 1967, American palaeontologist [[Ruben A. Stirton]] subdivided Diprotodontoidea into one family, Diprotodontidae, with four [[subfamily|subfamilies]]; Diprotodontinae (containing ''Diprotodon'' among others), Nototheriinae, Zygomaturinae, and Palorchestinae.<ref>{{cite journal|last1=Stirton|first1=R. A.|last2=Woodburne|first2=M. O.|last3=Plane|first3=M. D.|year=1967|title=A phylogeny of the Tertiary Diprotodontidae and its significance in correlation|publisher=Bureau of Mineral Resources|journal=Geology and Geophysics Bulletin|volume=85|pages=149–160}}</ref> In 1977, Australian palaeontologist Michael Archer synonymised Nototheriinae with Diprotodontinae.<ref name=Archer1977>{{cite journal|url=https://www.biodiversitylibrary.org/page/48741798#page/71/mode/1up|last=Archer|first=M.|year=1977|title=Origins and subfamilial relationships of ''Diprotodon'' (Diprotodontidae, Marsupialia)|journal=Memoirs of the Queensland Museum|volume=18|pages=37–39}}</ref> In 1978, Archer and Australian palaeontologist Alan Bartholomai elevated Palorchestinae to family level as [[Palorchestidae]], leaving Diprotodontoidea with families Diprotodontidae and Palorchestidae; and Diprotodontidae with subfamilies Diprotodontinae and Zygomaturinae.<ref>{{cite journal|first1=M.|last1=Archer|first2=A.|last2=Bartholomai|year=1978|title=Tertiary mammals of Australia: a synoptic review|journal=Alcheringa: An Australasian Journal of Palaeontology|volume=2|issue=1|page=8|doi=10.1080/03115517808619074|bibcode=1978Alch....2....1A }}</ref>

Below is the Diprotodontoidea family tree according to Australian palaeontologists [[Karen H. Black]] and Brian Mackness, 1999 (top),<ref name=Black1999/> and Vombatiformes family tree according to Beck ''et al.'' 2020 (bottom):<ref name=Beck2020/>

{{clade
|label1 = [[Diprotodontoidea]]
|1 = {{clade
 |1 = [[Palorchestidae]]
 |label2 = [[Diprotodontidae]]
 |2 = {{clade
  |label1 = [[Diprotodontinae]]
  |label2 = [[Zygomaturinae]]
  |1 = {{clade
   |1 = {{clade
    |1 = ''[[Ngapakaldia]]''
    |2 = ''[[Pitikantia]]''
    }}
   |2 = {{clade
    |1 = ''[[Bematherium]]''
    |2 = {{clade
     |1 = ''[[Pyramios]]''
     |2 = {{clade
      |1 = {{clade
       |1 = ''[[Meniscolophus]]''
       |2 = ''[[Euowenia]]''
       }}
      |2 = {{clade
       |1 = ''[[Euryzygoma]]''
       |2 = '''''Diprotodon'''''
       }}
      }}
     }}
    }}
   }}
  |2 = {{clade
   |1 = ''[[Silvabestius]]''
   |2 = {{clade
    |1 = ''[[Alkwertatherium]]''
    |2 = {{clade
     |1 = ''[[Nimbadon]]''
     |2 = {{clade
      |1 = {{clade
       |1 = ''[[Plaisiodon]]''
       |2 = ''[[Kolopsoides]]''
       }}
      |2 = {{clade
       |1 = ''[[Neohelos]]''
       |2 = {{clade
        |1 = ''[[Kolopsis]]''
        |2 = {{clade
         |1 = {{clade
          |1 = ''[[Maokopia]]''
          |2 = ''[[Hulitherium]]''
          }}
         |2 = ''[[Zygomaturus]]''
         }}
        }}
       }}
      }}
     }}
    }}
   }}
  }}
 }}
}}

{{clade
|label1 = [[Vombatiformes]]
|1 = {{clade
 |1 = [[Thylacoleonidae]]
 |2 = {{clade
  |label2 = [[Vombatomorphia]]
  |1 = [[Phascolarctidae]] (koalas)
  |2 = {{clade
   |1 = [[Vombatidae]] (wombats)
   |label2 = [[Diprotodontoidea]]
   |2 = {{clade
    |1 = ''[[Ngapakaldia]]''
    |2 = {{clade
     |1 = {{clade
      |1 = ''[[Nimbadon]]''
      |2 = ''[[Neohelos]]''
      }}
     |2 = {{clade
      |label2 = [[Diprotodontidae]]
      |1 = [[Palorchestidae]]
      |2 = {{clade
       |1 = ''[[Kolopsis]]''
       |2 = {{clade
        |1 = '''''Diprotodon'''''
        |2 = {{clade
         |1 = ''[[Euryzygoma]]''
         |2 = ''[[Zygomaturus]]''
         }}
        }}
       }}
      }}
     }}
    }}
   }}
  }}
 }}
}}

{{clear}}

===Evolution===
[[File:Euryzygoma dunense by Mobsby 1 clean.png|thumb|''Diprotodon'' may have evolved from ''[[Euryzygoma]]'' (skull above).<ref name=Price2009/>]]

Diprotodontidae is the most diverse family in Vombatomorphia; it was better adapted to the spreading dry, open landscapes over the last tens of millions of years than other groups in the infraorder, living or extinct.<ref>{{cite journal|last1=Black|first1=K. H.|last2=Camens|first2=A. B.|last3=Archer|first3=M.|last4=Hand|first4=S. J.|year=2012|title=Herds Overhead: ''Nimbadon lavarackorum'' (Diprotodontidae), Heavyweight Marsupial Herbivores in the Miocene Forests of Australia|journal=PLOS ONE|volume=7|issue=11|article-number=e48213|doi=10.1371/journal.pone.0048213|pmid=23185250 |pmc=3504027 |bibcode=2012PLoSO...748213B |doi-access=free }}</ref> ''Diprotodon'' has been found in every Australian state, making it the most-widespread Australian megafauna in the fossil record.{{efn|This does not necessarily indicate its dominance among Australian megafauna, because the bones of ''Diprotodon'' are enormous and incredibly robust, and are thus far more likely to fossilise and be discovered than those of other megafauna.{{sfn|Vickers-Rich|1991|loc=p. 1104}}}}<ref name=Price2021/> The oldest vombatomorph (and vombatiform) is ''[[Mukupirna]]'', which was identified in 2020 from [[Oligocene]] deposits of the South Australian [[Namba Formation]] dating to 26–25 million years ago. The group probably evolved much earlier. ''Mukupirna'' was already differentiated as a closer relative to wombats than other vombatiformes, and attained a massive size of roughly {{cvt|150|kg}}, whereas the last common ancestor of vombatiformes was probably a small, {{cvt|1–5.5|kg}} creature.<ref name=Beck2020>{{cite journal|first1=R. M. D.|last1=Beck|first2=J.|last2=Louys|first3=P.|last3=Brewer|first4=M.|last4=Archer|first5=K. H.|last5=Black|first6=R. H.|last6=Tedford|year=2020|title=A new family of diprotodontian marsupials from the latest Oligocene of Australia and the evolution of wombats, koalas, and their relatives (Vombatiformes)|journal=Scientific Reports|volume=10|issue=9741|page=9741 |doi=10.1038/s41598-020-66425-8|pmid=32587406 |pmc=7316786 |bibcode=2020NatSR..10.9741B }}</ref>

Both diprotodontines and zygomaturines were both apparently quite diverse over the [[Late Oligocene]] to [[Early Miocene]], roughly 23 million years ago. However, the familial and subfamilial classifications of diprotodontoids from this period are debated. Compared to zygomaturines, diprotodontines were rare during the Miocene, with the only identified genus being ''[[Pyramios]]''.<ref name=Black1999/> By the [[Late Miocene]], diprotodontians became the commonest marsupial order in fossil sites, a dominance that endures to the present day; the most-prolific diprotodontians have been diprotodontids and kangaroos. Diprotodontidae also began a [[gigantism]] trend, along with several other marsupials, probably in response to the lower-quality plant foods available in a drying climate, requiring them to consume much more.<ref name=Black2012>{{cite book|first1=K. H.|last1=Black|author-link=Karen H. Black|first2=M.|last2=Archer|first3=S. J.|last3=Hand|first4=H.|last4=Godthelp|year=2012|chapter=The Rise of Australian Marsupials: A Synopsis of Biostratigraphic, Phylogenetic, Palaeoecologic and Palaeobiogeographic Understanding|title=Earth and life: global biodiversity, extinction intervals and biogeographic perturbations through time|editor-first=J. A.|editor-last=Talent|publisher=Springer Verlag|pages=1040, 1047, 1051–1056|doi=10.1007/978-90-481-3428-1_35|isbn=978-90-481-3427-4 |url=https://www.researchgate.net/publication/259220987}}</ref><ref name=Black1999/> Gigantism appears to have evolved independently six times among the vombatiform lineages.<ref name=Beck2020/> Diprotodontine diversity returned in the Pliocene; Diprotodontidae reached peak diversity with seven genera,<ref name=Black1999>{{cite journal|first1=K. H.|last1=Black|author-link=Karen H. Black|first2=B. S.|last2=Mackness|year=1999|title=Diversity and relationships of diprotodontoid marsupials|journal=Australian Mammalogy|volume=21|pages=20–21}}</ref> coinciding with the spread of open forests.<ref name=Black2012/> In 1977, Archer said ''Diprotodon'' directly evolved from the smaller ''[[Euryzygoma]]'',<ref name=Archer1977/> which has been discovered in Pliocene deposits of eastern Australia predating 2.5 million years ago.<ref name=Price2009/>

In general, there is poor resolution on the ages of Australian fossil sites. While the [[geochronology]] of ''Diprotodon'' is one of best for Australian megafauna, it is still incomplete and the majority of remains are undated.<ref name=Price2021>{{cite journal|first1=G. J.|last1=Price|first2=K. E.|last2=Fitzsimmons|first3=A. D.|last3=Nguyen|first4=J.-x.|last4=Zhao|first5=Y.-x.|last5=Feng|first6=I. H.|last6=Sobbe|first7=H.|last7=Godthelp|first8=M.|last8=Archer|first9=S. J.|last9=Hand|year=2021|title=New ages of the world's largest-ever marsupial: ''Diprotodon optatum'' from Pleistocene Australia|journal=Quaternary International|volume=603|issue=5693|pages=64–73|doi=10.1016/j.quaint.2021.06.013|bibcode=2021QuInt.603...64P |hdl=1959.4/unsworks_76732|hdl-access=free}}</ref> Price and Australian palaeontologist Katarzyna Piper reported the earliest, indirectly dated ''Diprotodon'' fossils from the [[Nelson Bay Formation]] at [[Nelson Bay, New South Wales]], which dates to 1.77 million to 780,000 years ago during the [[Early Pleistocene]]. These remains are 8–17% smaller than those of Late Pleistocene ''Diprotodon'', but are otherwise indistinguishable.{{efn|They were unsure if it was appropriate to classify the Nelson Bay material into a new species based on the size and temporal difference, so they tentatively designated them as ''D. ?optatum''.<ref name=Price2009/>}}<ref name=Price2009>{{cite journal|last1=Price |first1=G. J.|last2=Piper |first2=K. J.|year= 2009|title=Gigantism of the Australian ''Diprotodon'' {{small|Owen 1838}} (Marsupialia, Diprotodontoidea) through the Pleistocene|journal=Journal of Quaternary Science|volume=24 |issue=8 |pages=1029–1038|doi=10.1002/jqs.1285|s2cid=84386678|doi-access=free|bibcode=2009JQS....24.1029P }}</ref> The oldest directly dated ''Diprotodon'' fossils come from the Boney Bite site at [[Floraville, New South Wales]]; they were deposited approximately 340,000 years ago during the [[Middle Pleistocene]] based on [[U-series dating]] and [[luminescence dating]] of [[quartz]] and [[orthoclase]]. Floraville is the only-identified Middle Pleistocene site in tropical northern Australia.<ref name=Price2021/> Beyond these, almost all dated ''Diprotodon'' material comes from [[Marine Isotope Stage 5]] (MIS5) or younger, that is, after 110,000 years ago during the [[Late Pleistocene]].<ref name=Price2009/>

==Description==

===Skull===
{{Multiple image|
|align=left
|image1=Three-dimensional-digital-reconstruction-of-the-jaw-adductor-musculature-of-the-extinct-marsupial-peerj-02-514-g002.jpg
|image2=Three-dimensional-digital-reconstruction-of-the-jaw-adductor-musculature-of-the-extinct-marsupial-peerj-02-514-g003.jpg
|footer=''Diprotodon'' skull reconstructions showing the cranial bones (left) and the [[frontal sinus]]es (right)
}}

''Diprotodon'' has a long, narrow skull.{{sfn|Vickers-Rich|1991|loc=p. 1102}} Like other marsupials, the top of the skull of ''Diprotodon'' is flat or depressed over the small [[braincase]] and the [[sinus (anatomy)|sinuses]] of the [[frontal bone]].{{sfn|Owen|1870|loc=p. 523}} Like many other giant vombatiformes, the [[frontal sinus]]es are extensive; in a specimen from [[Bacchus Marsh]], they take up {{cvt|2675|cc}}—roughly 25% of skull volume—whereas the brain occupies {{cvt|477|cc}}—only 4% of the skull volume. Marsupials tend to have smaller [[Brain–body mass ratio|brain-to-body mass ratio]]s than [[placental]] mammals. However these become more disparate the bigger the animal, which could be a response to a need to conserve energy, because the brain is a calorically expensive organ. Brain size is also proportional to the maternal metabolic rate, which is much less in marsupials, due to the shorter gestation period. The expanded sinuses increase the surface area available for the [[temporalis muscle]] to attach. This is important for biting and chewing, to compensate for a less massive braincase, as a result of a proportionally smaller brain.<ref>{{cite journal|url=https://museumsvictoria.com.au/media/4258/331-342_mmv74_sharp_4_web.pdf |archive-url=https://web.archive.org/web/20180719123229/https://museumsvictoria.com.au/media/4258/331-342_mmv74_sharp_4_web.pdf |archive-date=2018-07-19 |url-status=live|first=A. C.|last=Sharp|year=2016|title=A quantitative comparative analysis of the size of the frontoparietal sinuses and brain in vombatiform marsupials|journal=Memoirs of the Museum of Victoria|volume=74|pages=331–342|doi=10.24199/j.mmv.2016.74.23}}</ref> They may also have helped dissipate [[stress (mechanics)|stresses]] produced by biting more efficiently across the skull.<ref name="Sharpe2016">{{Cite journal|last1=Sharpe |first1=A. C.|last2=Rich |first2=T. H.|year= 2016|title=Cranial biomechanics, bite force and function of the endocranial sinuses in ''Diprotodon optatum'', the largest known marsupial|journal=Journal of Anatomy|volume=228 |issue=6 |pages=984–995|doi=10.1111/joa.12456 |pmc=5341585 |pmid=26939052}}</ref>

The [[occipital bone]], at the back of the skull, slopes forward at 45 degrees, unlike most modern marsupials, where it is vertical. The base of the occipital is significantly thickened. The [[occipital condyle]]s, a pair of bones that connect the skull with the [[vertebral column]], are semi-circular and the bottom half is narrower than the top. The inner border, which forms the [[foramen magnum]] where the [[spinal cord]] feeds through, is thin and well-defined. The top margin of the foramen magnum is somewhat flattened rather than arched. The foramen expands backwards and vertically towards the inlet, and is more-reminiscent of a short [[neural canal]] (the tube running through a vertebral centrum where the spinal cord passes through) than a foramen magnum.{{sfn|Owen|1870|loc=pp. 521–523}}

A [[sagittal crest]] extends across the midline of the skull from the supraoccipital (the top of the occipital bone) to the region between the eyes on the top of the head. The [[orbit (anatomy)|orbit]] (eye socket) is small and vertically oval-shaped. The [[nasal bone]]s slightly curve upwards until near their endpoint, where they begin to curve down, giving the bones a somewhat S-shaped profile. Like many marsupials, most of the [[nasal septum]] is made of bone rather than [[cartilage]]. The nose would have been quite mobile. The height of the skull from the peak of the occipital bone to the end of the nasals is strikingly almost uniform; the end of the nasals is the tallest point. The [[zygomatic arch]] (cheek bone) is strong and deep as in kangaroos but unlike those of koalas and wombats, and extends all the way from the supraoccipital.{{sfn|Owen|1870|loc=pp. 523–524}}

====Jaws====
[[File:Diprotodon, Natural History Museum, London, Mammals Gallery.JPG|thumb|''Diprotodon'' skull at the [[Natural History Museum, London]]]]

As in kangaroos and wombats, there is a gap between the jointing of the [[palate bone|palate]] (roof of the mouth) and the [[maxilla]] (upper jaw) behind the last molar, which is filled by the [[medial pterygoid plate]].{{sfn|Owen|1870|loc=p. 525}} This would have been the [[insertion (anatomy)|insertion]] for the [[medial pterygoid muscle]] that was involved in closing the jaw. Like many [[grazing (behaviour)|grazers]], the [[masseter muscle]], which is also responsible for closing the jaw, seems to have been the dominant jaw muscle. A large [[temporal muscle]] compared to the [[lateral pterygoid muscle]] may indicate, unlike in wombats, a limited range of side-to-side jaw motion. This means that ''Diprotodon'' would have been better at crushing rather than grinding food. The insertion of the masseter is placed forwards, in front of the orbits, which could have allowed better control over the incisors. ''Diprotodon''{{'s}} chewing strategy appears to align more with kangaroos than wombats: a powerful vertical crunch was followed by a transverse grinding motion.<ref name=Sharp2014>{{cite journal |last=Sharp |first=A. C. |year=2014 |title=Three dimensional digital reconstruction of the jaw adductor musculature of the extinct marsupial giant Diprotodon optatum |journal=PeerJ |volume=2 |article-number=e514 |issn=2167-8359 |doi=10.7717/peerj.514 |pmid=25165628 |pmc=4137671 |doi-access=free}}</ref>

As in other marsupials, the [[ramus of the mandible]], the portion that goes up to connect with the skull, angles inward. The [[condyloid process]], which connects the jaw to the skull, is similar to that of a koala. The ramus is straight and extends almost vertically, thickening as it approaches the [[body of the mandible]] where the teeth are. The depth of the body of the mandible increases from the last molar to the first. The strong [[mandibular symphysis]], which fuses the two halves of the mandible, begins at the front-most end of the third molar;{{sfn|Owen|1870|loc=pp. 526–527}} this would prevent either half of the mandible from moving independently of the other, unlike in kangaroos which use this ability to better control their incisors.<ref name=Sharp2014/>

====Teeth====
[[File:Diprotodon molars.jpg|thumb|''Diprotodon'' [[molar (tooth)|molars]]]]

The [[dental formula]] of ''Diprotodon'' is {{DentalFormula|upper=3.0.1.4|lower=1.0.1.4}}. In each half of either jaw are three incisors in the upper jaw and one in the lower jaw; there are one [[premolar]] and four molars in both jaws but no [[canine (tooth)|canines]]. A long [[diastema]] (gap) separates the incisors from the molars.{{sfn|Owen|1870|loc=p. 528}}

The incisors are scalpriform ([[chisel]]-like). Like those of wombats and [[rodent]]s, the first incisors in both jaws continuously grew throughout the animal's life but the other two upper incisors did not. This combination is not seen in any living marsupial. The cross-section of the upper incisors is circular. In one old male specimen, the first upper incisor measures {{cvt|11|in|order=flip}} of which {{cvt|8.5|in|order=flip}} is within the tooth socket; the second is {{cvt|4|in|order=flip}} and {{cvt|1|in|order=flip}} is in the socket; and the exposed part of the third is {{cvt|2.6|in|order=flip}}. The first incisor is convex, and curves outwards, but the other two are concave.{{sfn|Owen|1870|loc=pp. 528–530}} The lower incisor has a faint upward curve, but is otherwise straight and has an oval cross-section. In the same old male specimen, the lower incisor measures {{cvt|10|in|order=flip}}, of which {{frac|2|3}} is inside the socket.{{sfn|Owen|1870|loc=p. 533}}

The premolars and molars are [[Molar (tooth)#Lophodont|bilophodont]], each having two distinct lophs (ridges). The premolar is triangular and about half the size of the molars.<ref name=Huxley1862>{{cite journal|last=Huxley|first=T. H.|author-link=Thomas H. Huxley|year=1862|title=On the Premolar Teeth of ''Diprotodon'', and on a New Species of that Genus|journal=Quarterly Journal of the Geological Society|volume=18|issue=1–2|pages=422–427|doi=10.1144/gsl.jgs.1862.018.01-02.56|bibcode=1862QJGS...18..422H |s2cid=131284050 |url=https://zenodo.org/record/1793193 }}</ref> As in kangaroos, the necks of the lophs are coated in [[cementum]]. Unlike in kangaroos, there is no connecting ridge between the lophs. The peaks of these lophs have a thick [[tooth enamel|enamel]] coating that thins towards the base; this could wear away with use and expose the [[dentine]] layer, and beneath that osteodentine.{{sfn|Owen|1870|loc=pp. 530–532}} Like the first premolar of other marsupials, the first molar of ''Diprotodon'' and wombats is the only tooth that is [[deciduous teeth|replaced]].{{sfn|Owen|1870|loc=p. 539}} ''D. optatum'' premolars were highly morphologically variable even within the same individual.<ref>{{Cite journal |last1=Price |first1=Gilbert J. |last2=Sobbe |first2=Ian H. |date=7 September 2010 |title=Morphological variation within an individual Pleistocene Diprotodon optatum Owen, 1838 (Diprotodontinae; Marsupialia): implications for taxonomy within diprotodontoids |url=http://www.tandfonline.com/doi/abs/10.1080/03115511003793553 |journal=[[Alcheringa: An Australasian Journal of Palaeontology]] |language=en |volume=35 |issue=1 |pages=21–29 |doi=10.1080/03115511003793553 |issn=0311-5518 |access-date=6 May 2024 |via=Taylor and Francis Online|url-access=subscription }}</ref>

===Vertebrae===
{{technical|section|date=September 2025}}
''Diprotodon'' had seven cervical (neck) vertebrae.<ref>{{cite book |last1=Murray |first1=Peter |title=Diprotodon: background and interpretation of the display in the Central Australian Museum |date=1995 |publisher=Museum and Art Gallery of the Northern Territory |location=Northern Territory, Australia}}</ref> The [[atlas (anatomy)|atlas]], the first cervical (C1), has a pair of deep cavities for insertion of the occipital condyles. The diaphophyses of the atlas, an upward-angled projection on either the side of the vertebra, are relatively short and thick, and resemble those of wombats and koalas. The articular surface of the [[axis (anatomy)|axis]] (C2), the part that joints to another vertebra, is slightly concave on the front side and flat on the back side. As in kangaroos, the axis has a low subtriangular hypophysis projecting vertically from the underside of the vertebra and a proportionally long odontoid—a projection from the axis which fits into the atlas—but the neural spine, which projects vertically the topside of the vertebra, is more forwards. The remaining cervicals lack a hypophysis. As in kangaroos, C3 and C4 have a shorter and more-compressed neural spine, which is supported by a low ridge along its midline in the front and the back. The neural spine of C5 is narrower but thicker, and is supported by stronger-but-shorter ridges.{{sfn|Owen|1870|loc=pp. 539–542}} C7 had a forked shape on top of the neural spine.<ref>{{cite book |last1=Murray |first1=Peter |title=Diprotodon: background and interpretation of the display in the Central Australian Museum |date=1995 |publisher=Museum and Art Gallery of the Northern Territory |location=Northern Territory, Australia}}</ref>

[[File:Lake Callabonna Diprotodon (3).jpg|thumb|left|Mounted skeleton, [[Museums Victoria]]]]

''Diprotodon'' probably had 13 [[dorsal vertebra]]e and 14 pairs of closely spaced [[rib]]s.{{sfn|Owen|1870|loc=p. 548}} Like many other mammals, the dorsals initially decrease in breadth and then expand before connecting to the [[lumbar vertebra]]e. Unusually, the front dorsals match the short proportions of the cervicals, and the articular surface is flat. At the beginning of the series, the neural spine is broad and angled forward, and is also supported by a low ridge along its midline in the front and the back. In later examples, the neural spine is angled backwards and bifurcates (splits into two). Among mammals, bifurcation of the neural spine is only seen in elephants and humans, and only in a few of the cervicals and not in the dorsals. Compared to those of wombats and kangaroos, the neural arch is proportionally taller. As in elephants, the [[epiphysial plate]]s (growth plates) and the neural arch, to which  the neural spine is attached, are [[anchylosis|anchylosed]]—very rigid in regard to the vertebral centrum—which served to support the animal's immense weight.{{sfn|Owen|1870|loc=pp. 542–544}}

Like most marsupials, ''Diprotodon'' likely had six lumbar vertebrae.{{efn|Wombats have four lumbar vertebrae and koalas have five.{{sfn|Owen|1870|loc=p. 545}}}} They retain a proportionally tall neural arch but not the diapophyses, though L1 can retain a small protuberance on one side where a diapophysis would be in a dorsal vertebra; this has been documented in kangaroos and other mammals. The length of each vertebra increases along the series so the lumbar series may have bent downward.{{sfn|Owen|1870|loc=pp. 545–546}}

Like other marsupials, ''Diprotodon'' had two [[sacrum|sacral vertebrae]]. The base of the neural spines of these two were [[ossified]] (fused) together.{{sfn|Owen|1870|loc=pp. 554–556}}

===Limbs===
====Girdles====
The general proportions of the [[scapula]] (shoulder blade) align more closely with more-basal vertebrates such as [[monotreme]]s, [[bird]]s, [[reptile]]s, and [[fish]] rather than other marsupials and [[placental mammal]]s. It is triangular and proportionally narrow but unlike most mammals with a triangular scapula, the arm attaches to top of the scapula and the subspinous fossa (the [[fossa (anatomy)|fossa]], a depression below the [[spine of scapula|spine of the scapula]]) becomes bigger towards the arm joint rather than decreasing. The [[glenoid cavity]] where the arm connects is oval shaped as in most mammals.{{sfn|Owen|1870|loc=pp. 548–550}}

Unlike other marsupials, the [[ilium (bone)|ilia]], the large wings of the [[pelvis]], are lamelliform (short and broad, with a flat surface instead of an [[iliac fossa]]). Lamelliform ilia have only been recorded in [[elephant]]s, [[sloth]]s, and [[ape]]s, though these groups all have a much-longer sacral vertebra series whereas marsupials are restricted to two sacral vertebrae. The ilia provided strong muscle attachments that were probably oriented and used much the same as those in an elephant. The [[sacroiliac joint]] where the pelvis connects to the spine is at 35 degrees in reference to the long axis of the ilium. The [[ischium|ischia]], which form part of the [[hip socket]], are thick and rounded tailwards but taper and diverge towards the socket, unlike those in kangaroos, where the ischia proceed almost parallel to each other. They were not connected to the vertebra. The hip socket itself is well-rounded and almost hemispherical.{{sfn|Owen|1870|loc=pp. 554–560}}

====Long bones====
Unlike those of most marsupials, the humerus of ''Diprotodon'' is almost straight rather than S-shaped, and the [[trochlea of humerus|trochlea of the humerus]] at the elbow joint is not perforated. The ridges for muscle attachments are poorly developed, which seems to have been compensated for by the powerful forearms. Similarly, the condyles where the [[radius (bone)|radius]] and [[ulna]] (the forearm bones) connect maintain their rounded shape and are quite-similarly sized, and unusually reminiscent of the condyles between the [[femur]] and the [[tibia]] and [[fibula]] in the leg of a kangaroo.{{sfn|Owen|1870|loc=pp. 551–554}}

{{Multiple image
|image1 = Diprotodon femur interior.jpg
|image2 = Diprotodon femur exterior.jpg
|footer = Different views of a ''Diprotodon'' femur
}}
Like elephants, the femur of ''Diprotodon'' is straight and compressed anteroposteriorly (from headside to tailside). The walls of the femur are prodigiously thickened, strongly constricting the [[medullary cavity]] where the [[bone marrow]] is located. The proximal end (part closest to the hip joint) is notably long, broad, and deep. The [[femoral head]] projects up far from the [[greater trochanter]]. As in kangaroos, the greater trochanter is split into two lobes. The [[femoral neck]] is roughly the same diameter as the femoral head. Also as in kangaroos, the condyle for the fibula is excavated out but the condyle for the tibia is well-rounded and hemispherical. Like those of many other marsupials, the tibia is twisted and the tibial [[malleolus]] (on the ankle) is reduced.{{sfn|Owen|1870|loc=pp. 560–566}}

====Paws====
''Diprotodon'' has five digits on either paw. Like other [[plantigrade]] walkers, where the paws were flat on the ground, the wrist and ankle would have been largely rigid and inflexible.<ref name=Stirling1899/><ref name=Weisbecker2008/> The digits are proportionally weak so the paws probably had a lot of padding.{{sfn|Vickers-Rich|1991|loc=p. 1102}} Similarly, the digits do not seem to have been much engaged in weight bearing.<ref name=Weisbecker2008/><ref name=Carey2011/>

The forepaw was strong and the shape of the wrist bones is quite similar to those of kangaroos. Like other vombatiformes, the [[metacarpal]]s, which connect the fingers to the wrist, are broadly similar to those of kangaroos and allies.<ref name=Weisbecker2008>{{cite journal|first1=V.|last1=Weisbecker|first2=M.|last2=Archer|year=2008|title=Parallel evolution of hand anatomy in kangaroos and vombatiform marsupials: Functional and evolutionary implications|journal=Palaeontology|volume=51|issue=2|pages=321–338|doi=10.1111/j.1475-4983.2007.00750.x|s2cid=82172054 |doi-access=free|bibcode=2008Palgy..51..321W }}</ref> The enlarged [[pisiform bone]] takes up half the jointing surface of the ulna. The fifth digit on the forepaw is the largest.<ref name=Stirling1899>{{cite book|first1=E. C.|last1=Stirling|first2=A. H. C.|last2=Zietz|author-link=Edward Charles Stirling|year=1899|title=Description of the manus and pes of Diprotodon australis|series=Fossil Remains of Lake Callabonna|publisher=Memoirs of the Royal Society of South Australia|pages=1–40}}</ref>

The digits of the hindpaws turn inwards from the ankle at 130 degrees. The [[second metatarsal|second]] and [[third metatarsal]]s (the [[metatarsal]]s connect the toes to the ankle) are significantly reduced, which may mean these digits were [[syndactyly|syndactylous]] (fused) like those of all modern diprotodontians. The first, fourth, and fifth digits are enlarged. The toes are each about the same length, except the fifth which is much stouter.<ref>{{cite journal|first1=A.|last1=Camens|first2=R.|last2=Wells|year=2009|title=Palaeobiology of Euowenia grata (Marsupialia: Diprotodontinae) and its Presence in Northern South Australia|journal=Journal of Mammalian Evolution|volume=17|issue=1|pages=9–10|doi=10.1007/s10914-009-9121-2|s2cid=42667860 }}</ref>

===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. |author1-link=Stephen Wroe | 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 up to {{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"/>

==Paleobiology==

===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 |article-number=230991 |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/>

===Migration and sociality===
[[File:Condamine River ChinchillaQLD 2012mar.JPG|thumb|left|One ''Diprotodon'' herd was making seasonal migrations along the [[Condamine River]] (above).<ref name="Price2017"/>]]

In 2017,  by measuring the [[Isotopes of strontium|strontium isotope]] ratio (<sup>87</sup>Sr/<sup>86</sup>Sr) at various points along the ''Diprotodon'' incisor QMF3452 from the Darling Downs, and matching those ratios to the ratios of sites across that region, Price and colleagues determined ''Diprotodon'' made seasonal migrations, probably in search of food or watering holes. This individual appears to have been following the [[Condamine River]] and, while apparently keeping to the Darling Downs during the three years this tooth had been growing, it would have been annually making a {{cvt|200|km}} northwest-southeast round trip. This trek parallels the [[List of mammals that perform mass migrations|mammalian mass migrations]] of modern-day East Africa.<ref name="Price2017">{{cite journal|last1= Price|first1=G.J.|last2= Ferguson|first2=K.J.|last3=Webb|first3=G.E.|last4= Feng|first4= Y.|last5= Higgins |first5= P.|last6= Nguyen |first6=A.D. |last7= Zhao|first7= J.|last8= Joannes-Boyau |first8= R. |last9= Louys |first9= J. |display-authors=6 |year= 2017 |title= Seasonal migration of marsupial megafauna in Pleistocene Sahul (Australia–New Guinea) |journal= Proceedings of the Royal Society B: Biological Sciences |volume= 284 |issue= 1863 |article-number= 20170785 |doi= 10.1098/rspb.2017.0785 |pmid=28954903 |pmc= 5627191}}</ref>

''Diprotodon'' is the only identified [[metatherian]]{{efn|Metatheria includes marsupials and all [[theria]]n mammals more closely related to marsupials than placentals.}} that seasonally migrated between two places. A few modern marsupials, such as the red kangaroo, have been documented making migrations when necessary but it is not a seasonal occurrence. Because ''Diprotodon'' could do it, it is likely other Pleistocene Australian megafauna also had seasonal migrations.<ref name="Price2017"/>

''Diprotodon'' apparently moved in large herds. Possible fossilised herds, which are most-commonly unearthed in south-eastern Australia, seem to be mostly or entirely female, and sometimes travelled with juveniles. Such [[Sexual segregation (biology)|sexual segregation]] is normally seen in [[polygyny in animals|polygynous]] species; it is a common social organisation among modern megaherbivores involving an entirely female herd save for their young and the dominant male, with which the herd exclusively breeds.<ref name=Price2008/> Similarly, the skull is adapted to handling much-higher stresses than that which resulted from bite alone so ''Diprotodon'' may have subjected its teeth or jaws to more-strenuous activities than chewing, such as fighting other ''Diprotodon'' for mates or fending off predators, using the incisors.<ref name=Sharpe2016/> Like modern red and grey kangaroos, which also sexually segregate, [[bachelor herd]]s of ''Diprotodon'' seem to have been less tolerant to drought conditions than female herds due to their larger size and nutritional requirements.<ref name=Price2008/>

===Gait===
[[File:VVP fossil tracks.png|thumb|upright=1.4|Fossil tracks from the [[Victorian Volcanic Plain grasslands|Victorian Volcanic Plain site]]: a) ''[[Protemnodon]]'', b) ''Diprotodon'' pes, c) ''Diprotodon'' overlain by a [[vombatid]], d) ''[[Thylacoleo]]'']]

The locomotion of an extinct animal can be inferred using [[fossil trackway]]s, which seldom preserve in Australia over the [[Cenozoic]]. Only the trackways of humans, kangaroos, vombatids, ''Diprotodon'', and the diprotodontid ''[[Euowenia]]'' have been identified.<ref name=Camens2009>{{cite journal|first1=A.|last1=Camens|first2=R.|last2=Wells|year=2009|title=Diprotodontid Footprints from the Pliocene of Central Australia|journal=Journal of Vertebrate Paleontology|volume=29|issue=3|pages=863–869|doi=10.1671/039.029.0316|bibcode=2009JVPal..29..863C |s2cid=128776520 |url=http://doc.rero.ch/record/208748/files/PAL_E3968.pdf |archive-url=https://web.archive.org/web/20170921220511/http://doc.rero.ch/record/208748/files/PAL_E3968.pdf |archive-date=2017-09-21 |url-status=live }}</ref> ''Diprotodon'' trackways have been found at Lake Callabonna<ref>{{cite journal|first=R. H.|last=Tedford|title=The diprotodons of Lake Callabonna|journal=Australian Natural History|volume=17|year=1973|page=354|url=https://museum-publications.australian.museum/aus-nat-hist-1973-v17-iss11/}}</ref> and the [[Victorian Volcanic Plain grasslands]].<ref name=Carey2011>{{cite journal|first1=S. P.|last1=Carey|first2=A. B.|last2=Camens|first3=M. L.|last3=Cupper|first4=R.|last4=Grün|first5=J. C.|last5=Hellstrom|first6=S. W.|last6=McKnight|first7=I.|last7=McLennan|first8=D. A.|last8=Pickering|first9=P.|last9=Trusler|first10=M.|last10=Aubert|year=2011|title=A diverse Pleistocene marsupial trackway assemblage from the Victorian Volcanic Plains, Australia|journal=Quaternary Science Reviews|volume=30|issue=5–6|pages=598–602|doi=10.1016/j.quascirev.2010.11.021|bibcode=2011QSRv...30..591C |hdl=1885/65964|hdl-access=free}}</ref><ref>{{cite journal|first1=A. B.|last1=Camens|first2=S. P.|last2=Carey|year=2013|title=Contemporaneous Trace and Body Fossils from a Late Pleistocene Lakebed in Victoria, Australia, Allow Assessment of Bias in the Fossil Record|journal=PLOS ONE|volume=8|issue=1|article-number=e52957|doi=10.1371/journal.pone.0052957 |doi-access=free |pmc=3534647|pmid=23301008|bibcode=2013PLoSO...852957C }}</ref> The diprotodontid manus (forepaw) print is semi-circular and the pes (hindpaw) is reniform (kidney-shaped).<ref name=Carey2011/> Owing to proportionally small digits, most of the weight was borne on the [[carpus]] and [[tarsus (skeleton)|tarsus]]—the bones connecting to respectively the wrist and the ankle. Diprotodontines seem to have had a much-more-erect gait, an adaptation to long-distance travel that is similar to that of elephants, rather than the more-sprawling posture of wombats and zygomaturines, though there are no fossil trackways of the latter to verify their reconstructed standing posture.<ref name=Camens2009/><ref name=Carey2011/>

At Lake Callabonna, the single ''Diprotodon'' responsible for the impressions had an average stride length of {{cvt|1500|mm|ftin|0}}, trackway width of {{cvt|430|mm|ftin|0}}, and track dimensions {{cvt|295x202|mm}} in length x width. The gleno-acetabular length—the distance between the shoulders and pelvis—could have been about {{cvt|1125|mm|ftin|0}}; assuming a hip height of {{cvt|900|mm|ftin}}, the maker of these tracks was probably moving at around {{cvt|6.3|kph}}.<ref name=Camens2009/>

The single ''Diprotodon'' responsible for the impressions at the volcanic plain had an average stride length of {{cvt|1310|mm|ftin|0}}, trackway width of {{cvt|660|mm|ftin|0}}, and pes length of {{cvt|450|mm|ftin|0}}. The gleno-acetabular length may have been about {{cvt|1080|mm|ftin|0}} and assuming a hip height of {{cvt|830|mm|ftin|0}}, the maker of the tracks was probably moving at around {{cvt|5.5|kph}}. Its posture was much-more-sprawled than the example from Callabonna, aligning more with what might be expected of ''Zygomaturus''. The animal may have been a female carrying a large joey in her pouch, the added weight on the stomach altering the gait. The first trackway continues for {{cvt|62.8|m}} in a south-easterly direction towards a palaeo-lake. The animal seems to have hesitated while stepping down from the first [[sand bar]] on its path with the right pes making three overlapping prints here while shuffling around. The trackway vanishes for a {{cvt|20|m}} stretch and reappears while the animal seemingly is stepping on wet sediment. Another diprotodontid trackway appears {{cvt|50|m}} away, moving southerly, which may have been left by the same individual.<ref name=Carey2011/>

===Life history===
The marsupial [[metabolic rate]] is about 30% lower than that of placentals due to a lower [[body temperature]] of {{cvt|34|to|36|C}}. Marsupials give birth at an earlier point in foetal development, relying on [[lactation]] to facilitate most of the joey's development; because pregnancy is much-more-energetically expensive, investing in lactation rather than longer gestation can be advantageous in a highly seasonal and unpredictable climate to minimise maternal nutritional requirements. Consequently, marsupials cannot support as large a litter size or as short a [[generation time]].<ref name=Tyndale2001>{{cite journal|last=Tyndale-Biscoe|first=C. H.|year=2001|title=Australasian marsupials—to cherish and to hold|journal=Reproduction, Fertility and Development|volume=13|issue=8|pages=477–485|doi=10.1071/RD01079|pmid=11999297 }}</ref>

Based on the relationship between female body size and life history in kangaroos, a {{cvt|1000|kg}} ''Diprotodon'' female would have gestated for six-to-eight weeks, and given birth to a single {{cvt|5|g}} joey. Given its massive size, ''Diprotodon'' may not have sat down to give birth as do smaller marsupials, possibly standing instead. Like koalas and wombats, the pouch may have faced backwards so the joey could crawl down across its mother's abdomen to enter and attach itself to a teat until it could see—perhaps 260 days—and [[thermoregulate]]. It would have permanently left the pouch after 860 days and suckled until reaching {{cvt|270|kg}} after four or five years.<ref name=Tyndale2001/>

In large kangaroos, females usually reach [[sexual maturity]] and enter [[estrous cycle|oestrus]] soon after weaning, and males need double the time to reach sexual maturity. A similar pattern could have been exhibited in ''Diprotodon''. Assuming a lifespan of up to 50 years, a female ''Diprotodon'' could have given birth eight times.<ref name=Tyndale2001/>

==Palaeoecology==
''Diprotodon'' was present across the entire Australian continent by the Late Pleistocene,<ref name=Price2021/> especially following MIS5 approximately 110,000 years ago.<ref name=Price2009/> The onset of the [[Quaternary glaciation]], with the continuous advance and retreat of glaciers at the poles, created extreme climatic variability elsewhere. In Australia, the warmer, wetter [[interglacial period]]s were received by forests and woodlands; colder, dryer [[glacial period]]s were more conducive to grasslands and deserts. The continent progressively became dryer as the Asian [[monsoon]]s became less influential over Australia: the vast interior had become arid and sandy by 500,000 years ago; the mega-lakes that were once prominent, especially during interglacials in north-western Australia, dried up; and the rainforests of eastern Australia gradually retreated. Aridity has hastened over the last 100,000 years, especially after 60,000 years ago with surging [[El Niño–Southern Oscillation]]s.<ref name=Black2012/>

The continent-wide distribution of ''Diprotodon'' indicates herds trekked across almost any habitat,<ref>{{Cite journal |last=Webb |first=Steve |date=20 January 2009 |title=Late Quaternary distribution and biogeography of the southern Lake Eyre basin (SLEB) megafauna, South Australia |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1502-3885.2008.00044.x |journal=[[Boreas (journal)|Boreas]] |language=en |volume=38 |issue=1 |pages=25–38 |doi=10.1111/j.1502-3885.2008.00044.x |bibcode=2009Borea..38...25W |issn=0300-9483 |access-date=6 May 2024 |via=Wiley Online Library}}</ref> much like modern African elephants south of the [[Sahara]].<ref name=Price2008/> ''Diprotodon'' was a member of a diverse assemblage of megafauna that were [[endemism|endemic]] to Pleistocene Australia; these also included the [[thylacine]], modern kangaroos, [[Sthenurinae|sthenurines]] (giant short-faced kangaroos), a diversity of modern and giant koala and wombat species,<ref name=Black2012/> the [[tapir]]-like ''[[Palorchestes]]'', the giant turtle ''[[Meiolania]]'', and the giant bird ''[[Genyornis]]''.<ref name=Flannery1990/> ''Diprotodon'' coexisted with the diprotodontid ''[[Zygomaturus|Zygomaturus trilobus]]'', which appears to have remained in the forests, whereas ''Diprotodon'' foraged the expanding grasslands and woodlands. Other contemporaneous dipotodontids (''[[Hulitherium]]'', ''Z. nimborensia'', and ''[[Maokopia]]'') were insular forms that were restricted to the forests of New Guinea.<ref name=Black2012/>

===Predation===
Due to its massive size, ''Diprotodon'' would have been a tough adversary for native carnivores. It contended with the largest-known marsupial predator ''[[Thylacoleo carnifex]]''; while ''Diprotodon'' remains that were gnawed or bitten by ''T. carnifex'' have been identified, it is unclear if the {{cvt|100|–|130|kg}} marsupial predator was powerful enough to kill an animal surpassing {{cvt|2000|kg}}. The modern [[jaguar]], at half the size of ''T. carnifex'', can kill a {{cvt|500|kg}} bull so it is possible ''T. carnifex'' could have killed small ''Diprotodon''.<ref>{{cite journal|last1=Wroe|first1=S.|last2=Myers|first2=T. J.|last3=Wells|first3=R. T.|last4=Gillespie|first4=A.|year=1999|title=Estimating the weight of the Pleistocene marsupial lion, ''Thylacoleo carnifex'' (Thylacoleonidae:Marsupialia): implications for the ecomorphology of a marsupial super-predator and hypotheses of impoverishment of Australian marsupial carnivore faunas|journal=Australian Journal of Zoology |volume=47|issue=5|page=495|doi=10.1071/zo99006}}</ref> Similar to recent kangaroos with thylacines or [[quoll]]s, juvenile ''Diprotodon'' may have been at high risk of predation by ''T. carnifex''; it and fossils of juvenile ''Diprotodon'' have been recovered from the same caves.{{sfn|Owen|1870|loc=p. 568}}

The largest predators of Australia were reptiles, most notably the [[saltwater crocodile]], the now-extinct crocodiles ''[[Paludirex]]'' and ''[[Quinkana]]'', and the giant lizard [[megalania]] (''Varanus priscus''). At {{cvt|7|m}} in length, megalania was the largest carnivore of Pleistocene Australia.<ref name=Flannery1990>{{cite journal|last=Flannery|first=T. F.|year=1990|title=Pleistocene faunal loss: implications of the aftershock for Australia's past and future|journal=Archaeology in Oceania|volume=25|issue=2|pages=45–55|doi=10.1002/j.1834-4453.1990.tb00232.x}}</ref>

===Extinction===

As part of the [[Quaternary extinction event]], ''Diprotodon'' and every other Australian land animal heavier than {{cvt|100|kg}} became extinct. The timing and the exact cause are unclear because there is poor resolution on the ages of Australian fossil sites. Since their discovery, the extinction of the Australian megafauna has usually been blamed on the changing climate or overhunting by the first [[Aboriginal Australian]]s.<ref name=David2021/> In 2001, Australian palaeontologist Richard Roberts and colleagues dated 28 major fossil sites across the continent, and were able to provide a precise date for megafaunal extinction. They found most disappear from the fossil record by 80,000 years ago, but ''Diprotodon''; the giant wombat ''[[Phascolonus]]''; ''Thylacoleo''; and the short-faced kangaroos ''[[Procoptodon]]'', ''[[Protemnodon]]'', and ''[[Simosthenurus]]'' were identified at [[Ned's Gully]], Queensland, and [[Kudjal Yolgah Cave]], Western Australia, which they dated to respectively 47,000 and 46,000 years ago. Thus, all of the Australian Pleistocene megafauna died out probably between about 50,000 and 41,000 years ago. There also seems to have been a diverse assemblage of megafauna just before their extinction, and all populations across at least western and eastern Australia died out at about the same time.<ref name="New Ages">{{cite journal|last1=Roberts |first1=R.G.|last2=Flannery |first2=T.F. |author2-link=Tim Flannery|author3=Ayliffe, L.K. |author4=Yoshida, H. |author5=Olley, J.M.|author6=Prideaux, G.J. |author7=Laslett, G.M. |author8=Baynes, A.|author9=Smith, M.A. |author10=Jones, R. |author11=Smith, B.L.|year=2001|title = New ages for the last Australian megafauna: Continent-wide extinction about 46,000&nbsp;years ago|journal=[[Science (journal)|Science]]|volume = 292 |issue = 5523 |pages = 1888–1892|doi=10.1126/science.1060264 |pmid=11397939|bibcode=2001Sci...292.1888R |s2cid=45643228|url = https://www.uow.edu.au/content/groups/public/@web/@sci/@eesc/documents/doc/uow014698.pdf}}</ref> As of 2021, there is still no solid evidence of megafauna surviving past approximately 40,000 years ago; their latest occurrence, including ''Diprotodon'', is recorded at South Walker Creek mine in the north-east at about 40,100 ± 1,700 years ago.<ref name=David2021>{{cite journal|first1=B.|last1=David|first2=L. J.|last2=Arnold|first3=J.-J.|last3=Delannoy|first4=J.|last4=Fresløve|first5=C.|last5=Urwin|first6=F.|last6=Petchey|first7=M. C.|last7=McDowell|first8=R.|last8=Mullette|first9=G.|last9=Kurnai|first10=J.|last10=Mialanes|first11=R.|last11=Wood|first12=J.|last12=Crouch|first13=J.|last13=Berthet|first14=V. N. L.|last14=Wong|first15=H.|last15=Green|first16=J.|last16=Hellstrom|year=2021|title=Late survival of megafauna refuted for Cloggs Cave, SE Australia: Implications for the Australian Late Pleistocene megafauna extinction debate|journal=Quaternary Science Reviews|volume=253|article-number=106781|doi=10.1016/j.quascirev.2020.106781|bibcode=2021QSRv..25306781D |s2cid=234010059 }}</ref>

At the time Roberts ''et al.'' published their paper, the earliest evidence of human activity in Australia was 56±4 thousand years old, which is close to their calculated date for the megafauna extinction; they hypothesised human hunting had eradicated the last megafauna within about 10,000 years of coexistence. Human hunting had earlier been blamed for the extinction of North American and [[List of extinct New Zealand animals|New Zealand]] megafauna.<ref name="New Ages"/> Human activity was then generally regarded as the main driver of Australian megafaunal extinction, especially because the megafauna had survived multiple extreme drought periods during glacial periods. At the time, there did not seem to be any evidence of unusually extreme climate during this period.<ref name=Murphy2011>{{cite journal|first1=B. P.|last1=Murphy|first2=G. J.|last2=Williamson|first3=D. M. J. S.|last3=Bowman|year=2011|title=Did central Australian megafaunal extinction coincide with abrupt ecosystem collapse or gradual climate change?|journal=Global Ecology and Biogeography|volume=21|issue=2|pages=142–151|doi=10.1111/j.1466-8238.2011.00668.x}}</ref> Due to the slowness of marsupial reproduction, even limited megafaunal hunting may have severely weakened the population.<ref name=Tyndale2001/><ref name=Brook2006>{{cite journal|last1=Brook|first1=B. W.|last2=Johnson|first2=C. N.|year=2006|title=Selective hunting of juveniles as a cause of the imperceptible overkill of the Australian Pleistocene megafauna|journal=Alcheringa: An Australasian Journal of Palaeontology |volume=30|pages=39–48|doi=10.1080/03115510609506854|bibcode=2006Alch...30S..39B |s2cid=84205755 }}</ref>

[[File:Fire-stick- Lycett.webp|thumb|upright=1.3|The [[Aboriginal Australian]] practice of [[fire-stick farming]] (above depicts a [[kangaroo]] hunt) may be implicated in megafaunal extinction.<ref name=Miller2005/><ref name=David2021/>]]

In 2005, American geologist Gifford Miller noticed fire abruptly becomes more common about 45,000 years ago; he ascribed this increase to aboriginal [[fire-stick farming|fire-stick farmers]], who would have regularly started [[controlled burn]]s to clear highly productive forests and grasslands. Miller said this radically altered the vegetational landscape and promulgated the expanse of the modern-day fire-resilient scrub at the expense of the megafauna.<ref name=Miller2005>{{cite journal|first1=G. H.|last1=Miller|first2=M. L.|last2=Fogel|first3=J. W.|last3=Magee|first4=M. K.|last4=Gagan|first5=S. J.|last5=Clarke|first6=B. J.|last6=Johnson|year=2005|title=Ecosystem Collapse in Pleistocene Australia and a Human Role in Megafaunal Extinction|journal=Science|volume=309|issue=5732|pages=287–290|doi=10.1126/science.1111288|pmid=16002615 |bibcode=2005Sci...309..287M |s2cid=22761857 |url=https://doc.rero.ch/record/14709/files/PAL_E1537.pdf }}</ref><ref>{{cite journal|last1=Bowman|first1=D.M.J.|last2=Murphy|first2=B.P.|last3=McMahon|first3=C.R.|year=2010|title=Using carbon isotope analysis of the diet of two introduced Australian megaherbivores to understand Pleistocene megafaunal extinctions|journal=Journal of Biogeography|volume=37|issue=3 |pages=499–505|doi=10.1111/j.1365-2699.2009.02206.x |bibcode=2010JBiog..37..499B |s2cid=84274623 }}</ref> Subsequent studies had difficulty firmly linking controlled burns with major ecological collapse.<ref name=Murphy2011/><ref>{{Cite journal|last1=Johnson|first1=Chris N.|last2=Rule|first2=Susan|last3=Haberle|first3=Simon G.|last4=Kershaw|first4=A. Peter|last5=McKenzie|first5=G. Merna|last6=Brook|first6=Barry W.|date=February 2016|title=Geographic variation in the ecological effects of extinction of Australia's Pleistocene megafauna|journal=Ecography|language=en|volume=39|issue=2|pages=109–116|doi=10.1111/ecog.01612|doi-access=free|bibcode=2016Ecogr..39..109J }}</ref><ref>{{Cite journal|last1=Dodson|first1=J.|last2=Field|first2=J.H.|date=May 2018|title=What does the occurrence of ''Sporormiella'' (''Preussia'') spores mean in Australian fossil sequences?|journal=Journal of Quaternary Science|volume=33|issue=4|pages=380–392|doi=10.1002/jqs.3020|bibcode=2018JQS....33..380D|s2cid=133737405 }}</ref> The frequency of fire could have also increased as a consequence of megafaunal extinction because total plant consumption rapidly fell, leading to faster fuel buildup.<ref>{{cite journal|last=Rule|first=S.|author2=Brook, B. W.|author3=Haberle, S. G.|author4=Turney, C. S. M.|author5=Kershaw, A. P.|year=2012|title=The Aftermath of Megafaunal Extinction: Ecosystem Transformation in Pleistocene Australia|journal=Science|volume=335|issue=6075|pages=1483–1486|bibcode=2012Sci...335.1483R|doi=10.1126/science.1214261|pmid=22442481|s2cid=26675232}}</ref>

In 2017, the human-occupied [[Madjedbebe]] rock shelter on the northern Australian coast was dated to about 65,000 years ago, which if correct would mean humans and megafauna had coexisted for over 20,000 years.<ref name="ClarksonJacobs2017">{{cite journal|last1=Clarkson|first1=C.|last2=Jacobs|first2=Z.|last3=Marwick|first3=B.|last4=Fullagar|first4=R.|last5=Wallis|first5=L.|last6=Smith|first6=M.|last7=Roberts|first7=R. G. |title=Human occupation of northern Australia by 65,000 years ago|journal=Nature|volume=547|issue=7663|year=2017|pages=306–310|issn=0028-0836|doi=10.1038/nature22968|pmid=28726833|bibcode=2017Natur.547..306C|hdl=2440/107043|s2cid=205257212|url=https://digital.library.adelaide.edu.au/dspace/bitstream/2440/107043/2/hdl_107043.pdf |archive-url=https://web.archive.org/web/20190428141305/https://digital.library.adelaide.edu.au/dspace/bitstream/2440/107043/2/hdl_107043.pdf |archive-date=2019-04-28 |url-status=live|hdl-access=free}}</ref> Other authors have considered this dating questionable.<ref>{{Cite journal |last1=Williams |first1=Martin A. J. |last2=Spooner |first2=Nigel A. |last3=McDonnell |first3=Kathryn |last4=O'Connell |first4=James F. |date=January 2021 |title=Identifying disturbance in archaeological sites in tropical northern Australia: Implications for previously proposed 65,000-year continental occupation date |url=https://onlinelibrary.wiley.com/doi/10.1002/gea.21822 |journal=Geoarchaeology |language=en |volume=36 |issue=1 |pages=92–108 |doi=10.1002/gea.21822 |bibcode=2021Gearc..36...92W |issn=0883-6353|url-access=subscription }}</ref> In the 2010s, several ecological studies were published in support of major drought conditions coinciding with the final megafaunal extinctions.<ref name="Wroe2013">{{cite journal |last1=Wroe |first1=S. |last2=Field |first2=J.H. |last3=Archer |first3=M. |last4=Grayson |first4=D.K. |last5=Price |first5=G.J. |last6=Louys |first6=J. |last7=Faith |first7=J.T. |last8=Webb |first8=G.E. |last9=Davidson |first9=I. |last10=Mooney |first10=S.D.|year=2013|title=Climate change frames debate over the extinction of megafauna in Sahul (Pleistocene Australia-New Guinea) |journal=Proceedings of the National Academy of Sciences |volume=110 |issue=22 |pages=8777–8781 |doi=10.1073/pnas.1302698110 |issn=0027-8424 |pmc=3670326 |pmid=23650401 |bibcode=2013PNAS..110.8777W|doi-access=free }}</ref><ref>{{cite journal|first1=T. J.|last1=Cohen|first2=J. D.|last2=Jansen|first3=L. A.|last3=Gliganic|first4=J. R.|last4=Larsen|first5=G. C.|last5=Nanson|first6=J.-H.|last6=May|first7=B. G.|last7=Jones|first8=D. M.|last8=Price|title=Hydrological transformation coincided with megafaunal extinction in central Australia|journal=Geology|volume=43|year=2015|issue=3 |pages=195–198|doi=10.1130/G36346.1|bibcode=2015Geo....43..195C }}</ref><ref>{{cite journal |last1=Johnson |first1=C.N. |last2=Alroy |first2=J. |last3=Beeton |first3=N.J. |last4=Bird |first4=M.I. |last5=Brook |first5=B.W. |last6=Cooper |first6=A. |last7=Gillespie |first7=R. |last8=Herrando-Pérez |first8=S. |last9=Jacobs |first9=Z. |last10=Miller |first10=G.H. |last11=Prideaux |first11=G.J. |display-authors=6 |year=2016 |title=What caused extinction of the Pleistocene megafauna of Sahul? |journal=Proceedings of the Royal Society B: Biological Sciences |volume=283 |issue=1824 |article-number=20152399 |doi=10.1098/rspb.2015.2399 |issn=0962-8452 |pmc=4760161 |pmid=26865301 }}</ref><ref>{{cite journal|first1=S. A.|last1=Hocknull|first2=R.|last2=Lewis|first3=L. J.|last3=Arnold|first4=T.|last4=Pietsch|first5=R.|last5=Joannes-Boyau|first6=G. J.|last6=Price|first7=P.|last7=Moss|first8=R.|last8=Wood|first9=A.|last9=Dosseto|first10=J.|last10=Louys|first11=J.|last11=Olley|first12=R. A.|last12=Lawrence|year=2020|title=Extinction of eastern Sahul megafauna coincides with sustained environmental deterioration|journal=Nature Communications|volume=11|issue=1 |page=2250|doi=10.1038/s41467-020-15785-w|pmc=7231803|pmid=32418985|bibcode=2020NatCo..11.2250H }}</ref><ref>{{cite journal|first1=C. W.|last1=Kemp|first2=J.|last2=Tibby|first3=L. J.|last3=Arnold|first4=C.|last4=Barr|year=2019|title=Australian hydroclimate during Marine Isotope Stage 3: a synthesis and review|journal=Quaternary Science Reviews|volume=204|pages=94–104|doi=10.1016/j.quascirev.2018.11.016|bibcode=2019QSRv..204...94K |s2cid=134214134 }}</ref> Their demise may have been the result of a combination of climatic change, human hunting, and human-driven landscape changes.<ref name=David2021/>

==Cultural significance==
===Fossil evidence===
Despite the role the first Aboriginal Australians are speculated to have had in the extinction of ''Diprotodon'' and other mammalian megafauna in Australia, there is little evidence humans used them at all in the 20,000 years of coexistence. No fossils of mammalian megafauna suggestive of human butchery or cooking have been found.{{efn|The only potential direct evidence of human and mammalian megafauna interaction (that has not yet been revised) is a tibial fragment with a single notch belonging to either ''Sthenurus'' or ''Protemnodon'' (short faced kangaroos), identified in 1980 by Australian zoologist Michael Archer and colleagues in [[Mammoth Cave (Western Australia)|Mammoth Cave]], Western Australia.<ref>{{cite journal|last1=Archer|first1=M.|last2=Crawford|first2=I. M.|last3=Merrilees|first3=D.|year=1980|title=Incisions, breakages and charring, some probably manmade, in fossil bones from Mammoth Cave, Western Australia|journal=Alcheringa|volume=4|issue=2 |pages=115–131|doi=10.1080/03115518008619643|bibcode=1980Alch....4..115A }}</ref>}}<ref name=Langley2020/>

In 1984,  Gail Paton discovered an upper-right ''Diprotodon'' incisor (<sup>2</sup>I) bearing 28 visible cut marks in Spring Creek, south-western Victoria; Ron Vanderwald and Richard Fullager studied the incisor, which was split in half longitudinally, seemingly while the bone was still fresh but it was glued together before Vanderwald and Fullager could inspect it. Each piece measures {{cvt|40|cm}} in length. The marks are aligned in a straight line, and measure {{cvt|0.91–4.1|mm}} in length, {{cvt|0.14–0.8|mm}} in width, and {{cvt|0.02–0.24|mm}} in depth. They determined it was inconsistent with bite marks from scavenging ''Thylacoleo'' or [[Muridae|mice]], and concluded it was incised by humans with flint as a counting system or a random doodle.<ref>{{cite journal|last1=Vanderwal|first1=R.|last2=Fullagar|first2=R.|year=1989|title=Engraved ''Diprotodon'' tooth from the Spring Creek locality, Victoria|journal=Archaeology in Oceania|volume=24|issue=1|pages=13–16|doi=10.1002/j.1834-4453.1989.tb00201.x}}</ref> This specimen became one of the most-cited pieces of evidence humans and megafauna directly interacted until a 2020 re-analysis by Australian palaeoanthropologist Michelle Langley identified the engraver as most-likely a [[tiger quoll]].<ref name=Langley2020>{{Cite journal|last=Langley|first=Michelle C.|date=2020|title=Re-analysis of the "engraved" Diprotodon tooth from Spring Creek, Victoria, Australia|journal= Archaeology in Oceania|volume= 55|issue= 1|pages= 33–41|doi= 10.1002/arco.5209|issn=1834-4453|doi-access=|hdl=10072/395405|hdl-access=free}}</ref>

In 2016, Australian archaeologist Giles Hamm and colleagues unearthed a partial right radius belonging to a young ''Diprotodon'' in the [[Warratyi|Warratyi rock shelter]]. Because it lacks carnivore damage and the rock shelter is up a sheer face ''Diprotodon'' is unlikely to have climbed, they said humans were responsible for taking the ''Diprotodon'' to the site.<ref>{{Cite journal|last1= Hamm|first1=G.|last2= Mitchell|first2= P.|last3= Arnold|first3= L.J.|last4= Prideaux|first4= G.J.|last5= Questiaux|first5=D.|last6=.Spooner|first6= N.A.|last7= Levchenko|first7= V.A.|last8= Foley|first8= E.C.|last9= Worthy|first9= T.H.|last10= Stephenson|first10= B.|last11= Coulthard|first11= V.|date= November 2016|title= Cultural innovation and megafauna interaction in the early settlement of arid Australia|url= https://www.nature.com/articles/nature20125|journal= Nature|volume= 539|issue= 7628|pages= 280–283|doi= 10.1038/nature20125|pmid=27806378|bibcode=2016Natur.539..280H|s2cid=4470503|url-access= subscription}}</ref>

===Mythology===
[[File:Bunyip 1890 (cropped).jpg|left|thumb|''Diprotodon'', soon after discovery, was associated with the [[bunyip]] (above drawn by J. Mcfarlane, 1890).<ref name="Holden"/>]]

When the first massive fossils in Australia were dug up, it was not clear what animals they might have represented because there were no serious scientists on the continent. Local residents guessed some may have been the remains of rhinos or elephants. European settlers, the most-vocal of whom was Reverend John Dunmore Lang, forwarded these fossils as evidence of the [[Genesis flood narrative]]. Aboriginal Australians also attempted to fit the finds into their own religious ideas, quickly associating ''Diprotodon'' with the [[bunyip]]—a large, carnivorous lake monster. Many ethnologists and palaeontologists of the time believed the bunyip was a [[folk memory|tribal memory]] of the lumbering giant creature that probably frequented marshlands, though at the time it was uncertain if ''Diprotodon'' and other megafauna were indeed extinct because the Australian continent had not yet been fully explored by Europeans. Scientific investigation into the bunyip was stigmatised after a purported bunyip skull was sensationalised in 1846, and was put on display at the [[Australian Museum]]. The following year, however, Owen recognised it as the skull of a foal, and was surprised the burgeoning Australian scientific community could have erred so egregiously.<ref name="Holden"/>

In 1892, Canadian geologist [[Henry Yorke Lyell Brown]] reported that Aboriginal Australians identified ''Diprotodon'' fossils from [[Lake Eyre]] as those of the [[Rainbow Serpent]], which he thought was a giant, bottom-dwelling fish. This notion became somewhat popularised after English geologist [[John Walter Gregory]], who believed the god was a horned, scaly creature, conjectured it was a chimaera of ''Diprotodon''—which he believed had a horn—and a crocodile. Later workers continued to report some link between the Rainbow Serpent and either ''Diprotodon'' or crocodiles.<ref name=Smith2018/>

These kinds of suppositions are not testable and require stories to survive in [[oral tradition]] for tens of thousands of years.<ref name=Smith2018>{{cite journal|last=Smith|first=M. A.|title=The historiography of ''kardimarkara'': Reading a desert tradition as cultural memory of the remote past|journal=Journal of Social Archaeology|year=2019 |volume=19 |pages=1–20|doi=10.1177/1469605318817685 |s2cid=150217104 |doi-access=free}}</ref> If Pleistocene megafauna are the basis of some aboriginal mythology, it is unclear if the stories were based on the creatures when they were alive or their fossils being discovered long after their extinction.<ref>{{cite book|editor1-first = P. |editor1-last = Vikers-Rich |editor2-first = J. M. |editor2-last = Monaghan |editor3-first = R.F. |editor3-last = Baird |editor4-first = T.H. |editor4-last = Rich |year = 1991 |title = Vertebrate Palaeontology of Australasia |page = 2 |publisher = Pioneer Design Studio and Monash University |isbn = 978-0-909674-36-6 |url = https://archive.org/details/Vertebratepalae00PVic/page/2 }}</ref>

===Rock art representations===
{{See also|Indigenous Australian art}}

Aboriginal Australians decorated caves with paintings and drawings of several creatures, but the identities of the subjects are often unclear. In 1907, Australian anthropologist [[Herbert Basedow]] found footprint [[petroglyph]]s in [[Yunta, South Australia|Yunta Springs]] and Wilkindinna, South Australia, which he believed were those of ''Diprotodon''. In 1988, Australian historian [[Percy Trezise]] presented what he thought was a [[Quinkan rock art|Quinkan]] depiction of ''Diprotodon'' to the First Congress of the Australian Rock Art Research Association. Both of these claims have their faults because the depictions bear several features that are inconsistent with what is known about ''Diprotodon''. Unlike the [[realism (arts)|realism]] of most [[Cro-Magnon]] artworks, which are more easily identifiable as various animals, the subjects of Australian Aboriginal paintings can be mythological beings from [[the Dreaming]] rather than a corporeal subject, making the artwork much more stylistic and mostly uninterpretable by an outsider.<ref>{{cite journal|url=http://www.ifrao.com/wp-content/uploads/2014/08/30-2-Megafauna.pdf |archive-url=https://web.archive.org/web/20170529001735/http://www.ifrao.com/wp-content/uploads/2014/08/30-2-Megafauna.pdf |archive-date=2017-05-29 |url-status=live|first=R. G.|last=Bednarik|year=2013|title=Megafauna depictions in rock art|journal=Rock Art Research|volume=30|issue=2|pages=199–200}}</ref><ref>{{cite book|first=R. G.|last=Bednarik|year=2013|chapter=Animals and Pareidolia|title=Myths About Rock Art|publisher=Archaeopress|pages=20, 21, 26|doi=10.2307/j.ctvxrq1jr.4|isbn=978-1-78491-474-5}}</ref>

== See also ==
* [[Australian megafauna]]

==Notes==
{{Notelist}}

==References==
{{Reflist|25em}}

==External links==
{{Wikispecies|Diprotodon}}
* {{cite web
 |title=Megafauna
 |website=Australian Museum
 |url=https://australian.museum/learn/australia-over-time/megafauna/
}}
* {{cite web
 |url=https://phenome10k.org/diprotodon-optatum/
 |website=phenome10k.org
 |title=3D model of the skull of ''Diprotodon''
}}

==Further reading==
{{Commons category|Diprotodon}}
* {{cite book|first=D. |last=Clode|year=2009 |title=Prehistoric Giants: The megafauna of Australia|publisher=Museum Victoria|isbn=978-0-9803813-2-0}}
*{{cite journal|url=https://museum.wa.gov.au/sites/default/files/INDEX%20TO%20THE%20GENERA%20AND%20SPECIES%20OF%20FOSSIL%20MAMMALIA%20DESCRIBED%20FROM%20AUSTRALIA%20AND%20NEW%20GUINEA%20BETWEEN%20FROM%201838%20AND%201968.pdf |archive-url=https://web.archive.org/web/20140910200744/http://museum.wa.gov.au/sites/default/files/INDEX%20TO%20THE%20GENERA%20AND%20SPECIES%20OF%20FOSSIL%20MAMMALIA%20DESCRIBED%20FROM%20AUSTRALIA%20AND%20NEW%20GUINEA%20BETWEEN%20FROM%201838%20AND%201968.pdf |archive-date=2014-09-10 |url-status=live|first1=J. A.|last1=Mahoney|first2=W. D. L.|last2=Ride|year=1975|title=Index to the genera and species described from Australia and New Guinea from 1838 to 1968|journal=Western Australian Museum Special Publication|issue=6|page=87|ref={{harvid|Mahoney|1975}}}}
*{{cite book|first=R.|last=Owen|author-link=Richard Owen|year=1870|title=Restoration of an extinct elephantine marsupial (Diprotodon australis)|publisher=Taylor and Francis|url=https://wellcomecollection.org/works/zbbpym4z/items?}}
*{{cite book|editor-first=P.|editor-last=Vickers-Rich|editor2-first=J. M.|editor2-last=Monaghan|editor3-first=R. F.|editor3-last=Baird|editor4-first=T. H.|editor4-last=Rich|year=1991|title=Vertebrate palaeontology of Australasia|volume=- |publisher=Pioneer Design Studio in cooperation with the Monash University Publications Committee|doi=10.5962/bhl.title.60647|isbn=978-0-909674-36-6 |url=https://www.biodiversitylibrary.org/item/123394#page/3/mode/1up|ref={{harvid|Vickers-Rich|1991}}}}

{{Vombatiformes}}
{{Taxonbar|from=Q131563}}
{{Authority control}}

[[Category:Diprotodontids]]
[[Category:Pleistocene marsupials]]
[[Category:Pleistocene mammals of Australia]]
[[Category:Extinct mammals of Australia]]
[[Category:Prehistoric marsupial genera]]
[[Category:Prehistoric mammals of Australia]]
[[Category:Fossil taxa described in 1838]]
[[Category:Taxa named by Richard Owen]]
[[Category:Monotypic prehistoric mammal genera]]