Editing Diprotodon (section)

===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|page=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, though the familial and subfamilial classifications of diprotodontoids from this period is debated. Compared to zygomaturines, diprotodontines were rare during the Miocene, 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; at this point, the most-prolific diprotodontians were 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 }}</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—after 110,000 years ago during the [[Late Pleistocene]].<ref name=Price2009/>