View source for Diprotodontia

{{Taxobox
| name = Diprotodontia<ref name=msw3>{{MSW3 Groves|pages=43–70}}</ref>
| fossil_range = {{Fossil range|28|0}}[[Late Oligocene]] – Recent
| image = Macropus agilis - 02.jpg
| image_width = 230 px
| image_caption = A diprotodont, the [[Agile Wallaby]] (''Macropus agilis'')
| regnum = [[Animal]]ia
| phylum = [[Chordate|Chordata]]
| classis = [[Mammalia]]
| infraclassis = [[Marsupialia]]
| ordo = '''Diprotodontia'''
| ordo_authority = [[Richard Owen|Owen]], 1866
| subdivision_ranks = [[Suborder]]s
| subdivision = 
[[Vombatiformes]]<br/>[[Phalangeriformes]]<br/>[[Macropodiformes]]
}}

'''Diprotodontia''' ({{IPAc-en|icon|d|aɪ|ˌ|p|r|oʊ|t|ɵ|ˈ|d|ɒ|n|ʃ|ⁱ|ə}}; {{lang-el|διπρωτός}} ''diprotos'', meaning "two front" and οδοντος ''odontos'' meaning "teeth") is a large [[order (biology)|order]] of about 120 [[marsupial]] mammals including the [[kangaroo]]s, [[Wallaby|wallabies]], [[possum]]s, [[koala]], [[wombat]]s, and many others. Extinct diprotodonts include the [[rhinoceros]]-sized ''[[Diprotodon]]'', and ''[[Thylacoleo]]'', the so-called "marsupial lion".

== Characteristics ==

Living diprotodonts are almost all [[herbivore]]s, as were most of those that are now [[extinct]]. There are a few [[insectivore]] and [[omnivore]] diprotodonts, but these seem to have arisen as relatively recent adaptations from the mainstream herbivorous lifestyle. The extinct [[Thylacoleonidae|thylacoleonids]] ("marsupial lions") are the only known group to have exhibited [[carnivore|carnivory]] on a large scale.

Diprotodonts are restricted to [[Australasia]]. The earliest known fossils date to the late [[Oligocene]]. However it is certain that their genesis lies earlier than this, as there are large gaps in Australia's fossil record and virtually no fossil record at all in geologically active [[New Guinea]]. The great diversity of known Oligocene diprotodonts suggests that the order began to diverge well beforehand. 

Many of the largest and least athletic diprotodonts (along with a wide range of other Australian [[megafauna]]) became extinct when humans first arrived in Australia about 50,000 years ago. It is possible that this extinction occurred as a direct result of hunting, but was more probably a result of widespread habitat changes brought about by human activities—notably the use of fire.

There are two key anatomical features that, in combination, identify diprotodontia. Members of the order are, first, ''diprotodont'' (meaning "two front teeth"): they have a pair of large, procumbent incisors on the lower jaw, a common feature of many early groups of mammals and mammaliforms.  The diprotodont jaw is short, usually with three pairs of upper incisors ([[wombat]]s, like [[rodent]]s have only one pair), and no lower canines.

The second trait distinguishing diprotodonts is ''syndactyly'', a fusing of the second and third digits of the foot up to the base of the claws which leaves the claws themselves separate.  Digit five is usually absent, and digit four is often greatly enlarged.  

Syndactyly is not particularly common (though the [[Peramelemorphia|Australian omnivorous marsupials]] share it) and is generally posited as an adaptation to assist in climbing. Many modern diprotodonts, however, are strictly terrestrial, and have evolved further adaptations to their feet to better suit this lifestyle. This makes the history of the [[tree-kangaroo]]s particularly convoluted: it appears that the animals were arboreal at some time in the far distant past, moving afterward to the ground—gaining long kangaroo-like feet in the process—before returning to the trees, where they further developed a shortening and broadening of the hind feet and a novel climbing method.

== Fossil record ==
The earliest known [[fossil]] of Diprotodontia dates back to the [[Late Oligocene]] (23.03[[mya (unit)|mya]]-28.4mya), and the earliest identifiable species is ''[[Hypsiprymnodon bartholomaii]]'' from the [[Early Miocene]].<ref name=paleo>[http://paleodb.org/cgi-bin/bridge.pl?action=checkTaxonInfo&taxon_no=66275&is_real_user=1 The Paleobiology Database<!-- Bot generated title -->]</ref>

== Classification ==

Until recently there were only two [[suborder]]s in Diprotodontia: [[Vombatiformes]] which encompassed the [[wombat]]s and [[koala]] and [[Phalangerida]] which contained all other families. Kirsch et al. (1997) split the families  into three [[suborder]]s. In addition, the six [[Phalangeriformes]] families are split into two superfamilies.

'''Order DIPROTODONTIA'''
* Genus †[[Brachalletes]]
* Genus †[[Koalemas]]
* Genus †[[Sthenomerus]]
* Genus †[[Nimbadon]]
* Family †[[Thylacoleonidae]] ([[marsupial lion]]s)
* Family †[[Palorchestidae]]
* Family †[[Wynyardiidae]]
* '''Suborder [[Vombatiformes]]'''
** Family [[Phascolarctidae]]: Koala (1 species)
** Family [[Vombatidae]]: wombats (3 species)
** Family †[[Ilariidae]]
** Family †[[Diprotodontidae]]
* '''Suborder [[Phalangeriformes]]'''
** Superfamily [[Phalangeroidea]]
*** Family [[Phalangeridae]]: brushtail possums and cuscuses
*** Family [[Burramyidae]]: pygmy possums
** Superfamily [[Petauroidea]]
*** Family [[Tarsipedidae]]:  Honey possum
*** Family [[Petauridae]] ([[Striped Possum]], [[Leadbeater's Possum]], [[Yellow-bellied Glider]], [[Sugar Glider]], [[Mahogany Glider]], [[Squirrel Glider]])
*** Family [[Pseudocheiridae]]: ringtailed possums and allies
*** Family [[Acrobatidae]]: ([[Feathertail Glider]] and [[Feather-tailed Possum]])
* '''Suborder [[Macropodiformes]]'''
** Family †[[Balbaridae]] : basal quadrupedal kangaroos
** Family [[Macropodidae]]: kangaroos, wallabies and allies
** Family [[Potoroidae]]: bettongs, potaroos and rat-kangaroos
** Family [[Hypsiprymnodontidae]]: [[Musky Rat-kangaroo]]
** Family ?†[[Ganguroo]]
** Family ?†[[Galanaria]]
† means extinct family, genus or species.

== References ==
{{Reflist}}
{{morefootnotes|date=May 2008}}
* [http://sn2000.taxonomy.nl/Taxonomicon/TaxonTree.aspx?id=60464 The Taxonomicon]
* [http://www.fmnh.helsinki.fi/users/haaramo/Metazoa/Deuterostoma/Chordata/Synapsida/Metatheria/Notometatheria/Diprotodontia/Diprotodontia.htm Mikko Haaramo]
* {{cite journal |author=Kear, Benjamin P.; Cooke, Bernard N.; Archer, Michael; Flannery, Timothy F.  |title=Implications of a new species of the Oligo-Miocene kangaroo (Marsupialia: Macropodoidea) Nambaroo, from the Riversleigh World Heritage Area, Queensland, Australia |journal=Journal of Paleontology |volume=81 |issue=6 |pages=1147–67 |date=November 2007 |doi=10.1666/04-218.1 |url=http://jpaleontol.geoscienceworld.org/cgi/content/abstract/81/6/1147}} 

{{Mammals}}
{{Diprotodontia}}

[[Category:Diprotodonts| ]]
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