Diprotodontia
| Diprotodontia[1] Temporal range:Late Oligocene– Recent
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| Clockwise from upper left: femalekoala(Phascolarctos cinereus),mahogany glider(Petaurus gracilis), youngeastern grey kangaroo(Macropus giganteus) andSulawesi bear cuscus(Ailurops ursinus) | |
Scientific classification
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Infraclass: | Marsupialia |
| Clade: | Eomarsupialia |
| Order: | Diprotodontia Owen,1866 |
| Suborders | |
Diprotodontia(/daɪˌproʊtəˈdɒntiə/,fromGreek"two forward teeth" ) is the largest extantorderofmarsupials,with about 155 species,[2]including thekangaroos,wallabies,possums,koala,wombats,and many others. Extinct diprotodonts include thehippopotamus-sizedDiprotodon,andThylacoleo,the so-called "marsupial lion".
Characteristics
[edit]
Living diprotodonts are almost allherbivores,as were most of those that are nowextinct.A fewinsectivorousandomnivorousdiprotodonts are known, and thePotoroidaeare almost unique among vertebrates in being largelyfungivorous,but these seem to have arisen as relatively recent adaptations from the mainstream herbivorous lifestyle. The extinctthylacoleonids( "marsupial lions" ) are the only known group to have exhibitedcarnivoryon a large scale.[citation needed]
Diprotodonts are restricted toAustralasia.The earliest known fossils date to the lateOligocene,but their genesis certainly lies earlier than this, as large gaps occur in Australia's fossil record, with virtually no fossil record at all in geologically activeNew Guinea.The great diversity of known Oligocene diprotodonts suggests the order began to diverge well beforehand.[citation needed]
Many of the largest and least athletic diprotodonts (along with a wide range of otherAustralian megafauna) became extinct when humans first arrived in Australia about 50,000 years ago. Their extinction possibly 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.[citation needed]
Two key anatomical features, 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 (wombats,likerodentshave 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.[3]Digit five is usually absent, and digit four is often greatly enlarged.
Syndactyly is not particularly common (though theAustralian omnivorous marsupialsshare 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 thetree-kangaroosparticularly 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.[citation needed]
Fossil record
[edit]The earliest knownfossilof Diprotodontia dates back to theLate Oligocene(23.03 - 28.4 million years ago), and the earliest identifiable species isHypsiprymnodon bartholomaiifrom theEarly Miocene.[4]
Classification
[edit]| Cladogram of Diprotodontia by Upham et al. 2019[5][6]and Álvarez-Carretero et al. 2022[7][8] | |||||||||||||||||||||||||||||||||
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Until recently, only twosubordersin Diprotodontia were noted:Vombatiformeswhich encompassed thewombatsandkoalaandPhalangeridawhich contained all other families. Kirsch et al. (1997) split the families into threesuborders.In addition, the sixPhalangeriformesfamilies are split into two superfamilies. The Macropodiformes are probably nested within the Phalangeriformes, though whether they are sister to Phalangeroidea or Petauroidea is debated.[9]
Order Diprotodontia
- SuborderVombatiformes
- FamilyVombatidae:wombats(three species)
- FamilyPhascolarctidae:koala(one species)
- Family †Ilariidae
- Family †Maradidae
- Family †Diprotodontidae:(giant wombats)
- Family †Palorchestidae:(marsupial tapirs)
- Family †Thylacoleonidae:(marsupial lions)[10]
- Family †Wynyardiidae
- SuborderPhalangeriformes
- SuperfamilyPhalangeroidea
- FamilyPhalangeridae:(brushtail possumsandcuscuses)
- FamilyBurramyidae:(pygmy possums)
- Family †Ektopodontidae:(sprite possums)
- SuperfamilyPetauroidea
- FamilyTarsipedidae:(honey possum)
- FamilyPetauridae:(striped possum,Leadbeater's possum,yellow-bellied glider,sugar glider,mahogany glider,squirrel glider)
- FamilyPseudocheiridae:(ring-tailed possumsand allies)
- FamilyAcrobatidae:(feathertail gliderandfeather-tailed possum)
- SuperfamilyPhalangeroidea
- SuborderMacropodiformes
- Family †Balbaridae:(basal quadrupedal kangaroos)
- FamilyMacropodidae:(kangaroos,wallabiesand allies)
- FamilyPotoroidae:(bettongs,potoroos,andrat-kangaroos)
- FamilyHypsiprymnodontidae:(musky rat-kangaroo)
† means extinct family, genus or species
See also
[edit]References
[edit]- ^Groves, C. P.(2005).Wilson, D. E.;Reeder, D. M. (eds.).Mammal Species of the World: A Taxonomic and Geographic Reference(3rd ed.). Baltimore: Johns Hopkins University Press. pp. 43–70.ISBN0-801-88221-4.OCLC62265494.
- ^Meredith, Robert W.; Westerman, Michael; Springer, Mark S. (26 February 2009)."A phylogeny of Diprotodontia (Marsupialia) based on sequences for five nuclear genes"(PDF).Molecular Phylogenetics and Evolution.51(3): 554–571.doi:10.1016/j.ympev.2009.02.009.PMID19249373.Retrieved5 May2015.
- ^Tolweb
- ^The Paleobiology Database
- ^Upham, Nathan S.; Esselstyn, Jacob A.; Jetz, Walter (2019)."Inferring the mammal tree: Species-level sets of phylogenies for questions in ecology, evolution and conservation".PLOS Biol.17(12): e3000494.doi:10.1371/journal.pbio.3000494.PMC6892540.PMID31800571.
- ^Upham, Nathan S.; Esselstyn, Jacob A.; Jetz, Walter (2019)."DR_on4phylosCompared_linear_richCol_justScale_ownColors_withTips_80in"(PDF).PLOS Biology.17(12).doi:10.1371/journal.pbio.3000494.
- ^Álvarez-Carretero, Sandra; Tamuri, Asif U.; Battini, Matteo; Nascimento, Fabrícia F.; Carlisle, Emily; Asher, Robert J.; Yang, Ziheng; Donoghue, Philip C.J.; dos Reis, Mario (2022). "A species-level timeline of mammal evolution integrating phylogenomic data".Nature.602(7896): 263–267.doi:10.1038/s41586-021-04341-1.hdl:1983/de841853-d57b-40d9-876f-9bfcf7253f12.
- ^Álvarez-Carretero, Sandra; Tamuri, Asif U.; Battini, Matteo; Nascimento, Fabrícia F.; Carlisle, Emily; Asher, Robert J.; Yang, Ziheng; Donoghue, Philip C.J.; dos Reis, Mario (2022)."4705sp_colours_mammal-time.tree".Nature(602): 263–267.doi:10.1038/s41586-021-04341-1.hdl:1983/de841853-d57b-40d9-876f-9bfcf7253f12.
- ^Eldridge, Mark D B; Beck, Robin M D; Croft, Darin A; Travouillon, Kenny J; Fox, Barry J (2019-05-23)."An emerging consensus in the evolution, phylogeny, and systematics of marsupials and their fossil relatives (Metatheria)".Journal of Mammalogy.100(3): 802–837.doi:10.1093/jmammal/gyz018.ISSN0022-2372.
- ^Naish, Darren (2004)."Of koalas and marsupial lions: the vombatiform radiation, part I".Molecular Phylogenetics and Evolution.33(1). Scientific American, Inc.: 240–250.doi:10.1016/j.ympev.2004.05.004.PMID15324852.Retrieved24 October2015.
