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{{Short description|Extinct genus of marsupials}}
{{Taxobox
{{Automatic taxobox
| name = ''Thylacoleo''
| fossil_range = late [[Pliocene]]—late [[Pleistocene]]
| fossil_range = late [[Pliocene]]—late [[Pleistocene]]
| image = Thylacoleo BW.jpg
| image = Journal.pone.0208020.g011.tif
| image_caption = Skeletal diagram of ''T. carnifex'' (top) and restored musculature based on living marsupials (bottom)
| regnum = [[Animal]]ia
| taxon = Thylacoleo
| phylum = [[Chordate|Chordata]]
| classis = [[Mammal]]ia
| authority = [[Richard Owen|Owen]], 1859
| type_species = †'''''Thylacoleo carnifex'''''
| infraclassis = [[Marsupialia]]
| subdivision_ranks = Species
| ordo = [[Diprotodontia]]
| subdivision = *†''T. carnifex''
| familia = [[Thylacoleonidae]]
*†''T. crassidentatus''
| genus = '''''Thylacoleo'''''
*†''T. hilli''
| genus_authority = [[Richard Owen|Owen]], 1859
| subdivision_ranks = [[Species]]
| subdivision =
*''[[Thylacoleo hilli]]''
*''[[Thylacoleo crassidentatus]]''
*''[[Thylacoleo carnifex]]''
}}
}}
'''''Thylacoleo''''' ("Pouch Lion") is an [[extinct]] [[genus]] of carnivorous [[marsupial]]s that lived in [[Australia]] from the late [[Pliocene]] to the late [[Pleistocene]] (2 [[mya (unit)|MYA]] to 30,000 years ago). Some of these "[[marsupial lions]]" were the largest [[mammal]]ian predators in Australia of that time, with ''[[Thylacoleo carnifex]]'' approaching the weight of a small [[lion]].


'''''Thylacoleo''''' ("pouch lion") is an [[Extinction|extinct]] [[genus]] of carnivorous [[marsupial]]s that lived in [[Australia]] from the late [[Pliocene]] to the [[Late Pleistocene]] (until around 40,000 years ago), often known as '''marsupial lions'''. They were the largest and last members of the family [[Thylacoleonidae]], occupying the position of [[apex predator]] within Australian ecosystems. The largest and last species, ''Thylacoleo carnifex'', approached the weight of a [[lion]]ess. The estimated average weight for the species ranges from {{convert|101|to|130|kg|abbr=on}}.<ref>{{cite journal | doi=10.1007/s10914-013-9228-3 | volume=20 | issue=3 | title=The Bony Labyrinth in Diprotodontian Marsupial Mammals: Diversity in Extant and Extinct Forms and Relationships with Size and Phylogeny | journal=Journal of Mammalian Evolution | pages=191–198|year = 2013|last1 = Alloing-Séguier|first1 = Léanie| last2=Sánchez-Villagra | first2=Marcelo R. | last3=Lee | first3=Michael S. Y. | last4=Lebrun | first4=Renaud | s2cid=16385939 }}</ref>
There are many similarities between prehistoric [[Australian megafauna]] and some mythical creatures from the [[dreamtime (mythology)|aboriginal dreamtime]] {{fact|date=June 2008}}.

==Taxonomy==
The first ''Thylacoleo'' fossil findings, discovered by [[Thomas Mitchell (explorer)|Thomas Mitchell]] were found in the 1830s in the Wellington Valley of New South Wales, though not recognised as such at the time. The generic holotype, consisting of broken teeth, jaws, and a skull was discovered by a pastoralist, William Avery, near Lake Colungolac from which the species ''Thylacoleo carnifex'' was described by [[Richard Owen]].<ref name="Owen1859XVI">{{cite journal |year=1859 |title=XVI. On the fossil mammals of Australia.— Part I. Description of a mutilated skull of a large marsupial carnivore (Thylacoleo carnifex, Owen), from a calcareous conglomerate stratum, eighty miles S. W. Of Melbourne, Victoria |journal=Philosophical Transactions of the Royal Society of London |volume=149 |pages=309–322 |doi=10.1098/rstl.1859.0016 |s2cid=110651400}}</ref> It was not until 1966 that the first nearly-complete skeleton was found. The only pieces missing were a foot and the tail. Currently, the [[Nullarbor Plain]] of West Australia remains to be the greatest finding site. These fossils now reside at the Australian Museum.<ref name=":4">{{Cite web |last=Musser |first=Anne |date=29 November 2018 |title=Thylacoleo carnifex |url=http://australianmuseum.net.au/Thylacoleo-carnifex |access-date=7 May 2019 |website=Australian Museum}}</ref><ref name="Owen1883XV" />

The genus was first published in 1859, erected to describe the type species ''Thylacoleo carnifex''. The new taxon was established in examination of fossil specimens provided to [[Richard Owen]]. The familial alliance takes its name from this description, the so-called marsupial lions of [[Thylacoleonidae]].

The colloquial name "marsupial lion" alludes to the genus name, which was named after its superficial resemblance to the placental lion and its ecological niche as a large predator.

'''Genus:''' ''Thylacoleo'' (''Thylacopardus'') – Australia's marsupial lions, that lived from about 2&nbsp;million years ago, during the Late Pliocene Epoch and became extinct about 40,000 years ago, during the [[Late Pleistocene]] Epoch. Three species are known:

*''Thylacoleo carnifex'' The holotype cranium was collected from [[Western District Lakes|Lake Colongulac]] in 1843 by pastoralist William Adeney. A partial rostrum collected by Adeney in 1876 from the same locality would later be found to belong to the same individual.<ref>{{cite journal |last1= Gill |first1= E.D. |date=25 February 1973 |title= Antipodal distribution of the holotype bones of ''Thylacoleo carnifex'' Owen (Marsupialia) |journal= Science Reports of the Tohoku University. Second Series, Geology |volume= 6 |pages= 497–499 |url = https://tohoku.repo.nii.ac.jp/?action=repository_uri&item_id=10862&file_id=18&file_no=1 |access-date= 13 August 2020}}</ref> It was not until 1966 that the first nearly-complete skeleton was found.<ref name=":4" /><ref name="Owen1883XV" />
*''Thylacoleo crassidentatus'' lived during the [[Pliocene]], around 5&nbsp;million years ago, and was about the size of a large dog. Its fossils have been found in southeastern [[Queensland]].<ref name="Woods1956">{{cite journal |last1=Woods |first1=J. T. |title=The skull of Thylacoleo carnifex |journal=Memoirs of the Queensland Museum |date=1956 |volume=13 |pages=125–140 |url=https://www.biodiversitylibrary.org/part/303455}}</ref><ref name="Bartholomai1962">{{cite journal |last1=Bartholomai |first1=Alan |title=A new species of Thylacoleo and notes on some caudal vertebrae of Palorchestes azael |journal=Memoirs of the Queensland Museum |date=1962 |volume=14 |pages=33–40 |url=https://www.biodiversitylibrary.org/part/303461}}</ref>
*''Thylacoleo hilli'' lived during the Pliocene and was half the size of ''T.&nbsp;crassidentatus''. It is the oldest member of the genus.<ref name="Pledge1977"/>

Fossils of other representatives of Thylacoleonidae, such as ''[[Microleo]]'' and ''[[Wakaleo]]'', date back to the Late Oligocene Epoch, some 24&nbsp;million years ago.<ref>{{cite book | author = Long, J.A., Archer, M., Flannery, T. & Hand, S. | year = 2002 | title = Prehistoric Mammals of Australia and New Guinea - 100 million Years of Evolution | publisher = Johns Hopkins University Press | location = Baltimore | pages = 224pp}}</ref>

''T. hilli'' was described by [[Neville Pledge]] in a study published in the records of the South Australia Museum in 1977. The holotype is a third premolar, discovered at a cave in [[Curramulka]] in South Australia, exhibiting the carnivorous characteristics of the genus and around half the size of ''T. carnifex''. This tooth was collected by Alan Hill, a speleologist and founding member of the Cave Exploration Group of South Australia, while examining a site known as the "Town Cave" in 1956; the specific epithet ''hilli'' honours the collector of the first specimen.<ref name="Pledge1977">{{cite journal |last1=Pledge |first1=N.S. |authorlink1=Neville S. Pledge |title=A new species of ''Thylacoleo'' (Marsupialia: Thylacoleonidae) with notes on the occurrences and distribution of Thylacoleonidae in South Australia |journal=Records of the South Australian Museum |date=1977 |volume=17 |pages=277–283 |url=https://www.biodiversitylibrary.org/part/78709}}</ref> Material found amidst the fauna at [[Bow River (New South Wales)|Bow River]] in New South Wales, dated to the early [[Pliocene]], was also referred to the species in 1982.<ref name="Flannery1984">{{cite journal |last1=Flannery |first1=T.F. |last2=Archer |first2=M. |title=The macropodoids (Marsupialia) of the Early Pliocene Bow local fauna, central eastern New South Wales |journal=The Australian Zoologist |date=1984 |volume=21 |pages=357–383 |url=https://www.biodiversitylibrary.org/part/50064}}</ref>
A fragment of an incisor, unworn and only diagnosable to the genus, was located at a site in Curramulka, close to the Town Cave site, and referred to the species for the apparent correlation in size when compared to the better known ''T.&nbsp;carnifex''.<ref name="Pledge1992">{{cite journal |last1=Pledge |first1=Neville S. |title=The Curramulka local fauna: A new late Tertiary fossil assemblage from Yorke Peninsula, South Australia |journal=The Beagle: Occasional Papers of the Northern Territory Museum of Arts and Sciences |date=1992 |volume=9 |pages=115–142 |url=https://www.biodiversitylibrary.org/part/263122}}</ref>

The marsupial lion is classified in the order Diprotodontia along with many other well-known marsupials such as kangaroos, [[Phalangeriformes|possums]], and the [[koala]]. It is further classified in its own [[family (biology)|family]], the [[Thylacoleonidae]], of which three [[genus|genera]] and 11 [[species]] are recognised, all extinct. The term marsupial lion (lower case) is often applied to other members of this family. Distinct possum-like characteristics led ''Thylacoleo'' to be regarded as members of [[Phalangeroidea]] for a few decades. Though a few authors continued to hint at phalangeroid affinities for thylacoleonids as recently as the 1990s, cranial and other characters have generally led to their inclusion within [[vombatiformes]], and as stem-members of the wombat lineage.<ref name="Scientific American">{{cite journal |last1=Naish |first1=Darren |year=2004 |title=Of koalas and marsupial lions: the vombatiform radiation, part I |url=http://blogs.scientificamerican.com/tetrapod-zoology/2011/10/26/vombatiform-radiation-part-i/ |journal=Molecular Phylogenetics and Evolution |volume=33 |issue=1 |pages=240–250 |doi=10.1016/j.ympev.2004.05.004 |pmid=15324852 |accessdate=17 October 2014}}</ref> Marsupial lions and other ecologically and morphologically diverse vombatiforms were once represented by over 60 species of [[carnivorous]], [[herbivorous]], [[Terrestrial animal|terrestrial]] and [[arboreal]] forms ranging in size from 3&nbsp;kg to 2.5 tonnes. Only two families represented by four [[herbivorous]] species (koalas and three species of wombat) have survived into modern times and are considered the marsupial lion's closest living relatives.<ref name="Black et al 2014">{{cite journal |doi=10.1016/j.gr.2013.12.008 |title=Bearing up well? Understanding the past, present and future of Australia's koalas |journal=Gondwana Research |volume=25 |issue=3 |pages=1186–201 |year=2014 |last1=Black |first1=Karen |authorlink1 = Karen H. Black |last2=Price |first2=Gilbert J |last3=Archer |first3=Michael |last4=Hand |first4=Suzanne J |bibcode=2014GondR..25.1186B }}</ref>

==Evolution==
The ancestors of [[thylacoleonid]]s are believed to have been [[herbivore]]s, something unusual for carnivores. They are members of the [[Vombatiformes]], an almost entirely herbivorous order of marsupials, the only extant representatives of which are [[koala]]s and [[wombat]]s, as well as extinct members such as the [[diprotodontids]] and [[palorchestids]].<ref name="Black2012">{{cite book |last1=Black |first1=K. H. |url=https://www.researchgate.net/publication/259220987 |last2=Archer |first2=M. |last3=Hand |first3=S. J. |last4=Godthelp |first4=H. |title=Earth and Life |publisher=Springer Verlag |year=2012 |editor-last=Talent |editor-first=J. A. |pages=1040, 1047 |chapter=The Rise of Australian Marsupials: A Synopsis of Biostratigraphic, Phylogenetic, Palaeoecologic and Palaeobiogeographic Understanding |doi=10.1007/978-90-481-3428-1_35 |isbn=978-90-481-3427-4 |authorlink=Karen H. Black}}</ref> The group first appeared in the Late [[Oligocene]]. The earliest thylacoleonids like ''[[Microleo]]'' were small possum-like animals,<ref>{{cite journal |doi=10.26879/632 |title=A tiny new marsupial lion (Marsupialia, Thylacoleonidae) from the early Miocene of Australia |journal=Palaeontologia Electronica |volume=19 |issue=2 |year=2016 |last1=Gillespie |first1=Anna K |last2=Archer |first2=Michael |last3=Hand |first3=Suzanne J |doi-access=free }}</ref> with the group increasing in size during the [[Miocene]], with representatives like the leopard-sized ''[[Wakaleo]].'' The genus ''Thylacoleo'' first appeared during the [[Pliocene]], and represented the only extant genus of the family from that time until the end of the [[Pleistocene]]. The youngest representative of ''Thylacoleo'' and the thylacoleonids, ''T.&nbsp;carnifex'', is the largest known member of the family.<ref name="Black2012" /> The earliest thylacoleonids are thought to have been arboreal (tree dwelling) animals,<ref>{{Cite journal |last1=Gillespie |first1=Anna K. |last2=Archer |first2=Michael |last3=Hand |first3=Suzanne J. |date=2019-09-03 |title=Lekaneleo, a new genus of marsupial lion (Marsupialia, Thylacoleonidae) from the Oligocene–Miocene of Australia, and the craniodental morphology of L. roskellyae, comb. nov. |url=https://www.tandfonline.com/doi/full/10.1080/02724634.2019.1703722 |journal=Journal of Vertebrate Paleontology |language=en |volume=39 |issue=5 |pages=e1703722 |doi=10.1080/02724634.2019.1703722 |bibcode=2019JVPal..39E3722G |s2cid=214332715 |issn=0272-4634}}</ref> while ''Thylacoleo'' is thought to be terrestrial with some climbing capabilities.<ref name=":2">{{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 |pages=489–98 |doi=10.1071/ZO99006}}</ref>


==Description==
==Description==
[[Image:Marsupial Lion skeleton in Naracoorte Caves.jpg|thumb|left|Skeleton of a ''Thylacoleo carnifex'' in the Victoria Fossil Cave, Naracoorte Caves National Park.]]
Pound for pound, ''Thylacoleo carnifex'' had the strongest bite of any [[mammal]] species living or extinct; a {{kg to lb|100|abbr=yes|wiki=yes|precision=0}} ''T. carnifex'' had a bite comparable to that of a {{kg to lb|250|abbr=yes|precision=0}} [[Lion|African Lion]]<ref>[http://news.bbc.co.uk/2/hi/science/nature/4409039.stm BBC NEWS | Science/Nature | Marsupial munch tops big biters<!-- Bot generated title -->]</ref> and is thought to have hunted large animals such as ''[[Diprotodon]]'' spp. and giant [[kangaroo]]s. It also had extremely strong forelimbs, with retractable catlike claws, a trait previously unseen in marsupials. ''Thylacoleo'' also possessed enormous hooded claws set on large semi-opposable thumbs, which were used to capture and disembowel prey. The long muscular tail was similar to that of a kangaroo. Specialized tail bones called [[Chevron (anatomy)|chevrons]] allowed the animal to tripod itself, and freed the front legs for slashing and grasping. <ref>[http://www.pbs.org/wgbh/nova/bonediggers/thyl-nf.html NOVA | Bone Diggers | Anatomy of Thylacoleo | PBS<!-- Bot generated title -->]</ref>


''T. carnifex'' is the [[Largest mammals#Marsupials .28Marsupialia.29|largest]] carnivorous [[mammal]] known to have ever existed in Australia, and one of the largest [[metatheria]]n carnivores known (comparable to ''[[Thylacosmilus]]'' and ''[[Borhyaena]]'' species, but smaller than [[Proborhyaenidae|''Proborhyaena gigantea'']]). Individuals ranged up to around {{convert|75|cm|in|abbr=on}} high at the shoulder and about {{convert|150|cm|in|abbr=on}} from head to tail. Measurements taken from a number of specimens show they averaged {{convert|101|to|130|kg|lb|abbr=on}} in weight, although individuals as large as {{convert|124|-|160|kg|lb|abbr=on}} might not have been uncommon, and the largest weight was of {{convert|128|-|164|kg|lb|abbr=on}}. This would make it comparable to female lions and female [[tiger]]s in general size.<ref name=":2" /> Estimates of the size of ''T. carnifex'' based on dental remains are typically dubious, in contrast to estimates based on proximal limb bone circumference.<ref>{{Cite journal |last1=Wroe |first1=Stephen |last2=Myers |first2=Troy |last3=Seebacher |first3=Frank |last4=Kear |first4=Ben |last5=Gillespie |first5=Anna |last6=Crowther |first6=Mathew |last7=Salisbury |first7=Steve |date=Summer 2003 |title=An alternative method for predicting body mass: the case of the Pleistocene marsupial lion |url=https://www.cambridge.org/core/journals/paleobiology/article/abs/an-alternative-method-for-predicting-body-mass-the-case-of-the-pleistocene-marsupial-lion/A3DD985802D1BF1A361AFC1B7155C55B |journal=[[Paleobiology (journal)|Paleobiology]] |language=en |volume=29 |issue=3 |pages=403–411 |doi=10.1666/0094-8373(2003)029<0403:AAMFPB>2.0.CO;2 |bibcode=2003Pbio...29..403W |issn=0094-8373 |access-date=14 August 2024 |via=Cambridge Core}}</ref>
Its strong forelimbs, retracting claws and incredibly powerful jaws mean that it may have been possible for ''Thylacoleo'' to climb trees and perhaps to carry carcasses to keep the kill for itself (similar to the [[leopard]] today). Due to its unique predatory morphology, scientists repeatedly claim ''Thylacoleo'' to be the most specialized mammalian carnivore of all time. <ref>[http://news.nationalgeographic.com/news/2004/03/0305_040305_TVsuperpredator.html Extinct Australian "Lion" Was Big Biter, Expert Says<!-- Bot generated title -->]</ref>


=== Skull ===
''Thylacoleo'' was {{cm to in|71|abbr=yes|wiki=yes|precision=0}} at the shoulder and about {{cm to in|114|abbr=yes|precision=0}} long from head to tail. The ''T. carnifex'' species is the largest, and skulls indicate they averaged {{kg to lb|101|abbr=yes|precision=0}} to {{kg to lb|130|abbr=yes|precision=0}}, and individuals reaching {{kg to lb|124|abbr=yes|precision=0}} to {{kg to lb|160|abbr=yes|precision=0}} were common.<ref>{{cite journal|author = Wroe, S., Myers, T. J., Wells, R. T., and Gillespie, 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 | pages = 489–498|doi = 10.1071/ZO99006}}</ref>
[[Image:Thylacoleo skull.jpg|thumb|Skull of ''Thylacoleo carnifex'']]
Like other thylacoleonids, ''Thylacoleo'' had blade-like third [[premolar]] teeth in the upper and lower jaws, that functioned as the [[carnassial]] teeth, with these teeth being present much further forwards in the jaw than in other mammals.<ref name=":0">{{Cite journal |last=Werdelin |first=L |date=1988 |title=Circumventing a Constraint - the Case of Thylacoleo (Marsupialia, Thylacoleonidae) |url=http://www.publish.csiro.au/?paper=ZO9880565 |journal=Australian Journal of Zoology |language=en |volume=36 |issue=5 |pages=565 |doi=10.1071/ZO9880565 |issn=0004-959X}}</ref><ref name="rspb.royalsocietypublishing.org" /> Compared to earlier thyacoleonids, the third premolars were considerably enlarged.<ref name=":3">{{Cite journal |last=Gillespie |first=Anna K. |date=2023-01-16 |title=Two new marsupial lion taxa (Marsupialia, Thylacoleonidae) from the early and Middle Miocene of Australia |url=https://www.tandfonline.com/doi/full/10.1080/03115518.2022.2152096 |journal=Alcheringa: An Australasian Journal of Palaeontology |volume=47 |issue=4 |language=en |pages=506–521 |doi=10.1080/03115518.2022.2152096 |bibcode=2023Alch...47..506G |s2cid=256157821 |issn=0311-5518}}</ref> ''Thylacoleo'' also had a proportionally large pair of first [[incisor]]s in the upper and lower jaws, which functioned analogously to other carnivores [[Canine tooth|canine teeth]].<ref name=":0" /><ref>{{cite journal |last1=Wells |first1=Roderick T. |last2=Murray |first2=Peter F. |last3=Bourne |first3=Steven J. |year=2009 |title=Pedal morphology of the marsupial lion ''Thylacoleo carnifex'' (Diprotodontia: Thylacoleonidae) from the Pleistocene of Australia |journal=Journal of Vertebrate Paleontology |volume=29 |issue=4 |pages=1335–1340 |bibcode=2009JVPal..29.1335W |doi=10.1671/039.029.0424 |s2cid=86460654}}</ref> They also had true canines but they served little purpose as they were stubby and not very sharp.<ref name=":1">{{Cite web |title=Discovery and Interpretation |url=http://www.naturalworlds.org/thylacoleo/discovery/discovering/discovering_tc_1.htm |access-date=7 May 2019 |website=Natural Worlds}}</ref> Compared to earlier thylacoleonids, the number of [[Molar (tooth)|molar]] teeth was reduced.<ref name=":3" />


Pound for pound, ''T. carnifex'' had the strongest bite of any [[mammal]] species, living or extinct; a ''T.&nbsp;carnifex'' weighing {{convert|101|kg|abbr=on}} had a bite comparable to that of a 250&nbsp;kg African [[lion]], and research suggests that ''Thylacoleo'' could hunt and take prey much larger than itself.<ref name="rspb.royalsocietypublishing.org">{{Cite journal | doi=10.1098/rspb.2004.2986| pmid=15817436| pmc=1564077| title=Bite club: Comparative bite force in big biting mammals and the prediction of predatory behaviour in fossil taxa| journal=Proceedings of the Royal Society B: Biological Sciences| volume=272| issue=1563| pages=619–625| year=2005| last1=Wroe| first1=S.| last2=McHenry| first2=C.| last3=Thomason| first3=J.}}</ref> Larger animals that were likely prey include ''[[Diprotodon]]'' spp. and [[Protemnodon|giant kangaroos]]. It seems improbable that ''Thylacoleo'' could achieve as high a bite force as a modern-day lion; however, this might have been possible when taking into consideration the size of its brain and skull. Carnivores usually have rather large brains when compared to [[Herbivore|herbivorous]] marsupials, which lessens the amount of bone that can be devoted to enhancing bite force. ''Thylacoleo'' however, is thought to have had substantially stronger muscle attachments and therefore a smaller brain.<ref>{{Cite web|url=https://laelaps.wordpress.com/2007/08/31/thylacoleo-carnifex-ancient-australias-marsupial-lion/|title=Thylacoleo carnifex, ancient Australia's marsupial lion|last=Switek|first=Brian|date=31 August 2007|website=Laelaps|access-date=8 May 2019}}</ref> Some later studies questioned the ability of the canine teeth to deliver a killing bite.<ref name="figu2016">{{cite journal |last1=Figueirido |first1=Borja |last2=Martín-Serra |first2=Alberto |last3=Janis |first3=Christine M. |year=2016 |title=Ecomorphological determinations in the absence of living analogues: The predatory behavior of the marsupial lion (Thylacoleo carnifex) as revealed by elbow joint morphology |url=https://research-information.bris.ac.uk/ws/files/57326592/Figueirido_Martin_Serra_Janis.pdf |journal=Paleobiology |volume=42 |issue=3 |pages=508–531 |bibcode=2016Pbio...42..508F |doi=10.1017/pab.2015.55 |s2cid=87168573 |hdl=1983/1f3ac566-0b08-48fb-b27c-63fe4256c138}}</ref>
==Discoveries==
[[Image:Thylacoskullcope.jpg|thumb|left|Drawing of ''Thylacoleo carnifex'' skull fragments by Richard Owen.]]
''Thylacoleo'' was first described by Sir [[Richard Owen]] in 1859.{{Fact|date=February 2008}}


Using [[3D modeling]] based on [[X-ray computed tomography]] scans, marsupial lions were found to be unable to use the prolonged, suffocating bite typical of living big cats. They instead had an extremely efficient and unique bite; the incisors would have been used to stab at and pierce the flesh of their prey while the more specialised carnassials crushed the [[Vertebrate trachea|windpipe]], severed the [[spinal cord]], and lacerated the major [[blood vessel]]s such as the [[carotid artery]] and [[jugular vein]]. Compared to an African lion which may take 15 minutes to kill a large catch, the marsupial lion could kill a large animal in less than a minute.{{dubious|talk=Dubious claim|date=September 2024}} The skull was so specialized for big game that it was very inefficient at catching smaller animals, which possibly contributed to its extinction.<ref>[https://www.sciencedaily.com/releases/2008/01/080117093440.htm "Extinct Marsupial Lion Tops African Lion In Fight To Death"], ''[[Science Daily]]'', 17 January 2008.</ref><ref>{{cite web |url=http://www.theaustralian.com.au/news/health-science/marsupial-lion-was-fast-killer/story-e6frg8gf-1111115343423 |title=Marsupial lion was fast killer |archiveurl=https://web.archive.org/web/20090417020211/http://www.theaustralian.news.com.au/story/0,25197,23069545-30417,00.html |website=The Australian |date=18 January 2008 |archivedate=17 April 2009 |first1=Leigh |last1=Dayton}}</ref>
In 2002, a remarkably complete skeleton of ''T. carnifex'' was discovered in a limestone cave under [[Nullarbor Plain]], where the animal fell to its death through a narrow opening in the plain above.<ref>[http://news.bbc.co.uk/2/hi/science/nature/6296029.stm BBC News, "Caverns give up huge fossil haul", 25 January 2007].</ref>


==Taxonomy==
===Postcranium===
[[Image:Thylacoleo.jpg|thumb|Skull of ''Thylacoleo'']]
[[File:Thylacoleo skeleton in Naracoorte Caves (cropped).jpg|left|thumb|Skeleton at Naracoorte Caves]]
''Thylacoleo'' had highly mobile and powerful forelimbs used to grapple prey, with each [[Manus (anatomy)|manus]] having a single very large retractable hooked claw set on large semi-opposable thumbs, which are suggested to have been used deal a killing blow.<ref name="figu2016" />
'''Family:''' [[Thylacoleonidae]] ([[Marsupial lion]]s)


The hind feet had four functional toes, the first digit being much reduced in size, but possessing a roughened pad similar to that of [[Phalangeriformes|possums]], which may have assisted with climbing. The discovery in 2005 of a specimen which included complete hind feet provided evidence that the marsupial lion exhibited [[syndactyly]] (fused second and third toes) like other diprotodonts.<ref>{{cite journal|author1= Wells, R.T.|author2=Murray, P.F.|author3=Bourne, S.J.|year=2009|title=Pedal morphology of the marsupial lion ''Thylacoleo carnifex'' (Diprotodontia: Thylacoleonidae) from the Pleistocene of Australia|journal=Journal of Vertebrate Paleontology|volume=29|issue=4|pages=1335–1340|doi=10.1671/039.029.0424 |bibcode=2009JVPal..29.1335W |s2cid=86460654}}</ref>
Marsupial "lion" alludes to the superficial resemblance to the placental lion and its ecological niche as a large predator. ''Thylacoleo'' is not related to the modern lion ''[[Lion|Panthera leo]]''.


Its strong forelimbs and retracting claws mean that ''Thylacoleo'' possibly climbed trees and perhaps carried carcasses to keep the kill for itself (similar to the [[leopard]] today).<ref name="Claw">{{Cite journal|title = Behaviour of the Pleistocene marsupial lion deduced from claw marks in a southwestern Australian cave|journal = Scientific Reports|volume = 6|pages = 21372|last1=Arman |first1=Samuel D. |last2=Prideaux |first2=Gavin J. |date = 15 February 2016|doi = 10.1038/srep21372|pmid = 26876952|pmc = 4753435|bibcode = 2016NatSR...621372A|s2cid=3548956}}</ref> The climbing ability would have also helped them climb out of caves, which could therefore have been used as dens to rear their young.<ref name="Evans2018">{{cite journal|last1= Evans|first1=A. R.|last2= Wells|first2=R. T.|last3= Camens|first3=A. B.|title= New skeletal material sheds light on the palaeobiology of the Pleistocene marsupial carnivore, ''Thylacoleo carnifex''|journal=PLOS ONE|volume= 13|issue= 12|year= 2018|pages= e0208020|doi= 10.1371/journal.pone.0208020|pmid=30540785|pmc=6291118|bibcode=2018PLoSO..1308020W|doi-access=free}}</ref> Specialised tail bones called [[Chevron (anatomy)|chevrons]] strengthened the tail, likely allowing the animal to use it to prop itself up while rearing on its hind legs, which may have been done when climbing or attacking prey.<ref name="Evans2018" />
'''Genus:''' ''[[Thylacoleo]]'' (''Thylacopardus'') - Australia's marsupial lions, that lived from about 2 million years ago, during the late Pliocene and became extinct about 30,000 years ago, during the late Pleistocene epoch.


The [[lumbar]] region is relatively rigid and straight, and suggests that the lower back was relatively inflexible.<ref name="Evans2018" />
*''Thylacoleo hilli'' ([[Oligocene]], Pliocene)
*''Thylacoleo crassidentatus'' (Pliocene)
*''[[Thylacoleo carnifex]]'' (Pleistocene)


==Ecology==
The family it belonged to, the Thylacoleonidae, has fossil representatives (e.g. ''[[Priscileo]]'' and ''[[Wakaleo]]'') dating back to the late Oligocene, some 24 million years.<ref>{{cite book | author = Long, J.A., Archer, M., Flannery, T. & Hand, S. | year = 2002 | title = Prehistoric Mammals of Australia and New Guinea - 100 million Years of Evolution | publisher = Johns Hopkins University Press | location = Baltimore | pages = 224pp}}</ref>
[[File:Marsupial lion (Thylacoleo carnifex).png|thumb|Life restoration of ''Thylacoleo carnifex'']]
When ''Thylacoleo'' was first described by Richard Owen, he considered it to be a carnivore, based on the morphology of its skull and teeth.<ref name="Owen1859XVI" /> However other anatomists, such as [[William Henry Flower]] disagreed. Flower was the first to place ''Thylacoleo'' with the Diprotodonts, noting its skull and teeth to be laid out more like those of the [[koala]] and the [[wombat]], and suggested that it was more likely a herbivore. Owen did not disagree with Flower's placement of ''Thylacoleo'' with the Diprotodonts, but still maintained that it was a carnivore, despite its herbivorous ancestry.<ref name="wired2009">{{cite magazine | url=https://www.wired.com/2009/06/thylacoleo-herbivore-or-carnivore/?intcid=inline_amp | title=Thylacoleo: Herbivore or Carnivore? | magazine=Wired | last1=Switek | first1=Brian }}</ref> Owen found little support in his lifetime, despite the pointing out of ''Thylacoleo'''s retractable claws, something only found in mammalian carnivores,<ref name="Owen1883XV">{{cite journal|doi=10.1098/rstl.1883.0015|title=XV. On the affinities of thylacoleo |journal=Philosophical Transactions of the Royal Society of London |year=1883 |volume=174 |pages=575–582 |s2cid=111347165|issn=0261-0523|doi-access=free}}</ref> and its lack of any ability to chew plant material.<ref name="wired2009" /> In 1911, a study by Spencer and Walcott claimed that certain marks on the bones of megafauna had been made by ''Thylacoleo'', but according to Horton (1979) they were not sufficiently rigorous, resulting in their arguments being strongly challenged by later scholars, such as Anderson (1929), and later Gill (1951, 1952, 1954), thereby leaving the issue unresolved.<ref name="bite">{{Cite journal |last1=Horton |first1=D. R. |last2=Wright |first2=R. V. S. |year=1981 |title=Cuts on Lancefield Bones: Carnivorous Thylacoleo, Not Humans, the Cause |journal=Archaeology in Oceania |volume=16 |issue=2 |pages=73–80 |doi=10.1002/j.1834-4453.1981.tb00009.x |jstor=40386545}}</ref>


Besides the most common hypothesis that it was an active predator, a variety of other theories existed in the late 19th to early 20th centuries as to the diet and feeding of ''Thylacoleo'', with hypotheses of it being a scavenger filling the ecological niche of [[hyenas]],<ref name="scavenger">{{cite journal |last1=De Vis |first1=C. W. |year=1883 |title=On tooth-marked bones of extinct marsupials |url=https://www.biodiversitylibrary.org/part/28646 |journal=Proceedings of the Linnean Society of New South Wales |volume=8 |pages=187–190 |doi=10.5962/bhl.part.28646 |doi-access=free}}</ref> being a specialist of crocodile eggs,<ref name="Claw" /> or even a melon-eater.<ref name="melons">{{cite journal |last1=Anderson |first1=C. |year=1929 |title=Palaeontological notes no. 1. Macropus titan Owen and Thylacoleo carnifex Owen |journal=Records of the Australian Museum |volume=17 |pages=35–49 |doi=10.3853/j.0067-1975.17.1929.752 |doi-access=free}}</ref> As late as 1954, doubts were still being raised as to whether it was actually a hypercarnivore.<ref name="figu2016" />
==References==
{{reflist}}


In 1981, another paper was published arguing that certain cuts to bones of large marsupials had been caused by ''Thylacoleo''. This paper by Horton and Wright was able to counter earlier arguments that such marks were the result of humans, largely by pointing out the presence of similar marks on the opposite side of many bones. They concluded that humans were extremely unlikely to have made the marks in question, but that if so "they had set out to produce only marks consistent with what ''Thylacoleo'' would produce".<ref name="bite" /> Since then, the academic consensus has emerged that ''Thylacoleo'' was a predator and a hypercarnivore.<ref name="figu2016" />
==See also==

* [[Naracoorte Caves National Park]]
The marsupial lion's limb proportions and muscle mass distribution indicate that, although it was a powerful animal, it was not a particularly fast runner. Paleontologists conjecture that it was an [[ambush predator]], possibly using leaping.<ref name="Evans2018" /> Incisions on bones of the extinct large kangaroo ''[[Macropus titan]]'', and the general morphology of ''Thylacoleo'' suggests that it fed in a similar manner to modern cheetahs, by using their sharp teeth to slice open the ribcage of their prey, thereby accessing the internal organs. They may have killed by using their front claws as either stabbing weapons or as a way to grab their prey with strangulation or suffocation.<ref name="bite" />

Like many predators, it was probably also an opportunistic [[scavenger]], feeding on [[carrion]] and driving off less powerful predators from their kills. It also may have shared behaviours exhibited by recent [[diprotodont]] marsupials such as kangaroos, like digging shallow holes under trees to reduce body temperature during the day.<ref>{{cite book |last1=Tyndale-Biscoe |first1=Hugh |title=Life of marsupials |date=2005 |publisher=CSIRO |isbn=978-0-643-09220-4 |location=Collingwood, Vic.}}{{page needed|date=August 2018}}</ref>

Trace fossils in the form of claw marks and bones from caves in [[Western Australia]] analyzed by Gavin Prideaux et al. indicate marsupial lions could also climb rock faces, and likely reared their young in such caves as a way of protecting them from potential predators.<ref>{{Cite news | url=https://www.bbc.com/news/world-australia-35557269 | title=Marsupial lion 'could climb trees'| work=BBC News| date=2016-02-15}}</ref>

Analysis of finds on the Nullabor Plain suggests that ''Thylacoleo carnifex'' inhabited open, arid environments similar to those found across much of Australia today.<ref>{{Cite journal |last1=Prideaux |first1=Gavin J. |last2=Long |first2=John A. |last3=Ayliffe |first3=Linda K. |last4=Hellstrom |first4=John C. |last5=Pillans |first5=Brad |last6=Boles |first6=Walter E. |last7=Hutchinson |first7=Mark N. |last8=Roberts |first8=Richard G. |last9=Cupper |first9=Matthew L. |last10=Arnold |first10=Lee J. |last11=Devine |first11=Paul D. |last12=Warburton |first12=Natalie M. |date=January 2007 |title=An arid-adapted middle Pleistocene vertebrate fauna from south-central Australia |url=https://www.nature.com/articles/nature05471 |journal=Nature |language=en |volume=445 |issue=7126 |pages=422–425 |doi=10.1038/nature05471 |pmid=17251978 |bibcode=2007Natur.445..422P |issn=0028-0836}}</ref>

A 1985 study suggested that ''Thylacoleo carnifex'' was an apex predator that primarily fed on large bodied prey, which may have included the large kangaroos ''[[Sthenurus]]'', ''[[Procoptodon]], [[Protemnodon]], [[Macropus]]'' and ''[[Osphranter|Ostphranter]]'' as well as possibly the largest Australian marsupial, the rhinoceros-sized vombatoid ''[[Diprotodon]]''.<ref>{{Cite journal |last=Case |first=J. A. |date=1985-01-01 |title=Differences in prey utilization by Pleistocene marsupial carnivores, Thylacoleo carnifex (Thylacoleonidae) and Thylacinus cynocephalus (Thylacinidae). |url=https://www.publish.csiro.au/AM/AM85002 |journal=Australian Mammalogy |language=en |volume=8 |issue=1 |pages=45–52 |doi=10.1071/AM85002 |issn=0310-0049}}</ref>
== Extinction ==
{{Main|Late Pleistocene extinctions}}
''Thylacoleo'' is thought to have become extinct around 40,000 years ago as part of the [[Quaternary extinction event|Late Pleistocene megafauna extinctions]], essentially simultanteously with the vast majority of [[Australian megafauna]]. It has been contested as to the relative importance of climatic change vs the impact of recently arrived [[Indigenous Australians]] (who arrived in Australia around 50-60,000 years ago) in the extinctions. There is limited evidence of human interaction with extinct megafauna in Australia.<ref>{{Cite journal |last1=Hocknull |first1=Scott A. |last2=Lewis |first2=Richard |last3=Arnold |first3=Lee J. |last4=Pietsch |first4=Tim |last5=Joannes-Boyau |first5=Renaud |last6=Price |first6=Gilbert J. |last7=Moss |first7=Patrick |last8=Wood |first8=Rachel |last9=Dosseto |first9=Anthony |last10=Louys |first10=Julien |last11=Olley |first11=Jon |last12=Lawrence |first12=Rochelle A. |date=2020-05-18 |title=Extinction of eastern Sahul megafauna coincides with sustained environmental deterioration |journal=Nature Communications |language=en |volume=11 |issue=1 |page=2250 |doi=10.1038/s41467-020-15785-w |issn=2041-1723 |pmc=7231803 |pmid=32418985|bibcode=2020NatCo..11.2250H }}</ref>

== See also ==

* [[Drop bear]]
{{clear}}

==References==
{{Reflist}}


==External links==
==External links==
{{Wikispecies|Thylacoleo carnifex}}
{{Wikispecies|Thylacoleo}}
* [https://phys.org/news/2013-05-evidence-theory-humans-megafauna.html New study finds no evidence for theory humans wiped out megafauna]
* [http://www.naturalworlds.org/thylacoleo/index.htm Thylacoleo - Australia's Marsupial Lion]
* [http://www.thylacoleo.com/thylacoleo.html Thylacoleo in Pleistocene Australia]
* [http://www.naturalworlds.org/thylacoleo/index.htm ''Thylacoleo'' - Australia's Marsupial Lion]
* [https://web.archive.org/web/20101124102953/http://thylacoleo.com/thylacoleo.php ''Thylacoleo'' in Pleistocene Australia]
* [http://www.bio.usyd.edu.au/staff/swroe/swroe.htm Steve Wroe's Web Page: Australian Megafauna]
* [https://web.archive.org/web/20070426142324/http://www.bio.usyd.edu.au/staff/swroe/swroe.htm Steve Wroe's Web Page: Australian Megafauna]
* [http://www.cnn.com/2007/TECH/science/01/25/australia.fossils.reut/index.html BBC: Mega-marsupials once roamed Australia]
* [https://web.archive.org/web/20080727131817/https://www.museum.wa.gov.au/exhibitions/online/thylacoleo/hunter.asp Western Australian Museum: ''Thylacoleo'' - a voracious hunter]


[[Category:Prehistoric diprotodonts]]
[[Category:Prehistoric mammals of Australia]]
[[Category:Pliocene mammals]]
[[Category:Pleistocene mammals]]
[[Category:Pleistocene extinctions]]


{{Vombatiformes}}{{Taxonbar|from=Q312099}}
[[ca:Thylacoleo]]
[[fr:Thylacoleo]]
[[la:Thylacoleo]]
[[nl:Thylacoleo]]
[[pl:Lew workowaty]]
[[ru:Сумчатый лев]]
[[zh:袋獅]]


[[Category:Prehistoric vombatiforms]]
{{portal|Paleontology}}
[[Category:Prehistoric mammals of Australia]]
[[Category:Pliocene marsupials]]
[[Category:Pleistocene marsupials]]
[[Category:Pleistocene genus extinctions]]
[[Category:Carnivorous marsupials]]
[[Category:Prehistoric marsupial genera]]
[[Category:Taxa named by Richard Owen]]
[[Category:Fossil taxa described in 1859]]
[[Category:Apex predators]]

Latest revision as of 15:10, 6 December 2024

Thylacoleo
Temporal range: late Pliocene—late Pleistocene
Skeletal diagram of T. carnifex (top) and restored musculature based on living marsupials (bottom)
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Infraclass: Marsupialia
Order: Diprotodontia
Family: Thylacoleonidae
Genus: Thylacoleo
Owen, 1859
Type species
Thylacoleo carnifex
Species
  • T. carnifex
  • T. crassidentatus
  • T. hilli

Thylacoleo ("pouch lion") is an extinct genus of carnivorous marsupials that lived in Australia from the late Pliocene to the Late Pleistocene (until around 40,000 years ago), often known as marsupial lions. They were the largest and last members of the family Thylacoleonidae, occupying the position of apex predator within Australian ecosystems. The largest and last species, Thylacoleo carnifex, approached the weight of a lioness. The estimated average weight for the species ranges from 101 to 130 kg (223 to 287 lb).[1]

Taxonomy

[edit]

The first Thylacoleo fossil findings, discovered by Thomas Mitchell were found in the 1830s in the Wellington Valley of New South Wales, though not recognised as such at the time. The generic holotype, consisting of broken teeth, jaws, and a skull was discovered by a pastoralist, William Avery, near Lake Colungolac from which the species Thylacoleo carnifex was described by Richard Owen.[2] It was not until 1966 that the first nearly-complete skeleton was found. The only pieces missing were a foot and the tail. Currently, the Nullarbor Plain of West Australia remains to be the greatest finding site. These fossils now reside at the Australian Museum.[3][4]

The genus was first published in 1859, erected to describe the type species Thylacoleo carnifex. The new taxon was established in examination of fossil specimens provided to Richard Owen. The familial alliance takes its name from this description, the so-called marsupial lions of Thylacoleonidae.

The colloquial name "marsupial lion" alludes to the genus name, which was named after its superficial resemblance to the placental lion and its ecological niche as a large predator.

Genus: Thylacoleo (Thylacopardus) – Australia's marsupial lions, that lived from about 2 million years ago, during the Late Pliocene Epoch and became extinct about 40,000 years ago, during the Late Pleistocene Epoch. Three species are known:

  • Thylacoleo carnifex The holotype cranium was collected from Lake Colongulac in 1843 by pastoralist William Adeney. A partial rostrum collected by Adeney in 1876 from the same locality would later be found to belong to the same individual.[5] It was not until 1966 that the first nearly-complete skeleton was found.[3][4]
  • Thylacoleo crassidentatus lived during the Pliocene, around 5 million years ago, and was about the size of a large dog. Its fossils have been found in southeastern Queensland.[6][7]
  • Thylacoleo hilli lived during the Pliocene and was half the size of T. crassidentatus. It is the oldest member of the genus.[8]

Fossils of other representatives of Thylacoleonidae, such as Microleo and Wakaleo, date back to the Late Oligocene Epoch, some 24 million years ago.[9]

T. hilli was described by Neville Pledge in a study published in the records of the South Australia Museum in 1977. The holotype is a third premolar, discovered at a cave in Curramulka in South Australia, exhibiting the carnivorous characteristics of the genus and around half the size of T. carnifex. This tooth was collected by Alan Hill, a speleologist and founding member of the Cave Exploration Group of South Australia, while examining a site known as the "Town Cave" in 1956; the specific epithet hilli honours the collector of the first specimen.[8] Material found amidst the fauna at Bow River in New South Wales, dated to the early Pliocene, was also referred to the species in 1982.[10] A fragment of an incisor, unworn and only diagnosable to the genus, was located at a site in Curramulka, close to the Town Cave site, and referred to the species for the apparent correlation in size when compared to the better known T. carnifex.[11]

The marsupial lion is classified in the order Diprotodontia along with many other well-known marsupials such as kangaroos, possums, and the koala. It is further classified in its own family, the Thylacoleonidae, of which three genera and 11 species are recognised, all extinct. The term marsupial lion (lower case) is often applied to other members of this family. Distinct possum-like characteristics led Thylacoleo to be regarded as members of Phalangeroidea for a few decades. Though a few authors continued to hint at phalangeroid affinities for thylacoleonids as recently as the 1990s, cranial and other characters have generally led to their inclusion within vombatiformes, and as stem-members of the wombat lineage.[12] Marsupial lions and other ecologically and morphologically diverse vombatiforms were once represented by over 60 species of carnivorous, herbivorous, terrestrial and arboreal forms ranging in size from 3 kg to 2.5 tonnes. Only two families represented by four herbivorous species (koalas and three species of wombat) have survived into modern times and are considered the marsupial lion's closest living relatives.[13]

Evolution

[edit]

The ancestors of thylacoleonids are believed to have been herbivores, something unusual for carnivores. They are members of the Vombatiformes, an almost entirely herbivorous order of marsupials, the only extant representatives of which are koalas and wombats, as well as extinct members such as the diprotodontids and palorchestids.[14] The group first appeared in the Late Oligocene. The earliest thylacoleonids like Microleo were small possum-like animals,[15] with the group increasing in size during the Miocene, with representatives like the leopard-sized Wakaleo. The genus Thylacoleo first appeared during the Pliocene, and represented the only extant genus of the family from that time until the end of the Pleistocene. The youngest representative of Thylacoleo and the thylacoleonids, T. carnifex, is the largest known member of the family.[14] The earliest thylacoleonids are thought to have been arboreal (tree dwelling) animals,[16] while Thylacoleo is thought to be terrestrial with some climbing capabilities.[17]

Description

[edit]

T. carnifex is the largest carnivorous mammal known to have ever existed in Australia, and one of the largest metatherian carnivores known (comparable to Thylacosmilus and Borhyaena species, but smaller than Proborhyaena gigantea). Individuals ranged up to around 75 cm (30 in) high at the shoulder and about 150 cm (59 in) from head to tail. Measurements taken from a number of specimens show they averaged 101 to 130 kg (223 to 287 lb) in weight, although individuals as large as 124–160 kg (273–353 lb) might not have been uncommon, and the largest weight was of 128–164 kg (282–362 lb). This would make it comparable to female lions and female tigers in general size.[17] Estimates of the size of T. carnifex based on dental remains are typically dubious, in contrast to estimates based on proximal limb bone circumference.[18]

Skull

[edit]
Skull of Thylacoleo carnifex

Like other thylacoleonids, Thylacoleo had blade-like third premolar teeth in the upper and lower jaws, that functioned as the carnassial teeth, with these teeth being present much further forwards in the jaw than in other mammals.[19][20] Compared to earlier thyacoleonids, the third premolars were considerably enlarged.[21] Thylacoleo also had a proportionally large pair of first incisors in the upper and lower jaws, which functioned analogously to other carnivores canine teeth.[19][22] They also had true canines but they served little purpose as they were stubby and not very sharp.[23] Compared to earlier thylacoleonids, the number of molar teeth was reduced.[21]

Pound for pound, T. carnifex had the strongest bite of any mammal species, living or extinct; a T. carnifex weighing 101 kg (223 lb) had a bite comparable to that of a 250 kg African lion, and research suggests that Thylacoleo could hunt and take prey much larger than itself.[20] Larger animals that were likely prey include Diprotodon spp. and giant kangaroos. It seems improbable that Thylacoleo could achieve as high a bite force as a modern-day lion; however, this might have been possible when taking into consideration the size of its brain and skull. Carnivores usually have rather large brains when compared to herbivorous marsupials, which lessens the amount of bone that can be devoted to enhancing bite force. Thylacoleo however, is thought to have had substantially stronger muscle attachments and therefore a smaller brain.[24] Some later studies questioned the ability of the canine teeth to deliver a killing bite.[25]

Using 3D modeling based on X-ray computed tomography scans, marsupial lions were found to be unable to use the prolonged, suffocating bite typical of living big cats. They instead had an extremely efficient and unique bite; the incisors would have been used to stab at and pierce the flesh of their prey while the more specialised carnassials crushed the windpipe, severed the spinal cord, and lacerated the major blood vessels such as the carotid artery and jugular vein. Compared to an African lion which may take 15 minutes to kill a large catch, the marsupial lion could kill a large animal in less than a minute.[dubiousdiscuss] The skull was so specialized for big game that it was very inefficient at catching smaller animals, which possibly contributed to its extinction.[26][27]

Postcranium

[edit]
Skeleton at Naracoorte Caves

Thylacoleo had highly mobile and powerful forelimbs used to grapple prey, with each manus having a single very large retractable hooked claw set on large semi-opposable thumbs, which are suggested to have been used deal a killing blow.[25]

The hind feet had four functional toes, the first digit being much reduced in size, but possessing a roughened pad similar to that of possums, which may have assisted with climbing. The discovery in 2005 of a specimen which included complete hind feet provided evidence that the marsupial lion exhibited syndactyly (fused second and third toes) like other diprotodonts.[28]

Its strong forelimbs and retracting claws mean that Thylacoleo possibly climbed trees and perhaps carried carcasses to keep the kill for itself (similar to the leopard today).[29] The climbing ability would have also helped them climb out of caves, which could therefore have been used as dens to rear their young.[30] Specialised tail bones called chevrons strengthened the tail, likely allowing the animal to use it to prop itself up while rearing on its hind legs, which may have been done when climbing or attacking prey.[30]

The lumbar region is relatively rigid and straight, and suggests that the lower back was relatively inflexible.[30]

Ecology

[edit]
Life restoration of Thylacoleo carnifex

When Thylacoleo was first described by Richard Owen, he considered it to be a carnivore, based on the morphology of its skull and teeth.[2] However other anatomists, such as William Henry Flower disagreed. Flower was the first to place Thylacoleo with the Diprotodonts, noting its skull and teeth to be laid out more like those of the koala and the wombat, and suggested that it was more likely a herbivore. Owen did not disagree with Flower's placement of Thylacoleo with the Diprotodonts, but still maintained that it was a carnivore, despite its herbivorous ancestry.[31] Owen found little support in his lifetime, despite the pointing out of Thylacoleo's retractable claws, something only found in mammalian carnivores,[4] and its lack of any ability to chew plant material.[31] In 1911, a study by Spencer and Walcott claimed that certain marks on the bones of megafauna had been made by Thylacoleo, but according to Horton (1979) they were not sufficiently rigorous, resulting in their arguments being strongly challenged by later scholars, such as Anderson (1929), and later Gill (1951, 1952, 1954), thereby leaving the issue unresolved.[32]

Besides the most common hypothesis that it was an active predator, a variety of other theories existed in the late 19th to early 20th centuries as to the diet and feeding of Thylacoleo, with hypotheses of it being a scavenger filling the ecological niche of hyenas,[33] being a specialist of crocodile eggs,[29] or even a melon-eater.[34] As late as 1954, doubts were still being raised as to whether it was actually a hypercarnivore.[25]

In 1981, another paper was published arguing that certain cuts to bones of large marsupials had been caused by Thylacoleo. This paper by Horton and Wright was able to counter earlier arguments that such marks were the result of humans, largely by pointing out the presence of similar marks on the opposite side of many bones. They concluded that humans were extremely unlikely to have made the marks in question, but that if so "they had set out to produce only marks consistent with what Thylacoleo would produce".[32] Since then, the academic consensus has emerged that Thylacoleo was a predator and a hypercarnivore.[25]

The marsupial lion's limb proportions and muscle mass distribution indicate that, although it was a powerful animal, it was not a particularly fast runner. Paleontologists conjecture that it was an ambush predator, possibly using leaping.[30] Incisions on bones of the extinct large kangaroo Macropus titan, and the general morphology of Thylacoleo suggests that it fed in a similar manner to modern cheetahs, by using their sharp teeth to slice open the ribcage of their prey, thereby accessing the internal organs. They may have killed by using their front claws as either stabbing weapons or as a way to grab their prey with strangulation or suffocation.[32]

Like many predators, it was probably also an opportunistic scavenger, feeding on carrion and driving off less powerful predators from their kills. It also may have shared behaviours exhibited by recent diprotodont marsupials such as kangaroos, like digging shallow holes under trees to reduce body temperature during the day.[35]

Trace fossils in the form of claw marks and bones from caves in Western Australia analyzed by Gavin Prideaux et al. indicate marsupial lions could also climb rock faces, and likely reared their young in such caves as a way of protecting them from potential predators.[36]

Analysis of finds on the Nullabor Plain suggests that Thylacoleo carnifex inhabited open, arid environments similar to those found across much of Australia today.[37]

A 1985 study suggested that Thylacoleo carnifex was an apex predator that primarily fed on large bodied prey, which may have included the large kangaroos Sthenurus, Procoptodon, Protemnodon, Macropus and Ostphranter as well as possibly the largest Australian marsupial, the rhinoceros-sized vombatoid Diprotodon.[38]

Extinction

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Thylacoleo is thought to have become extinct around 40,000 years ago as part of the Late Pleistocene megafauna extinctions, essentially simultanteously with the vast majority of Australian megafauna. It has been contested as to the relative importance of climatic change vs the impact of recently arrived Indigenous Australians (who arrived in Australia around 50-60,000 years ago) in the extinctions. There is limited evidence of human interaction with extinct megafauna in Australia.[39]

See also

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References

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  1. ^ Alloing-Séguier, Léanie; Sánchez-Villagra, Marcelo R.; Lee, Michael S. Y.; Lebrun, Renaud (2013). "The Bony Labyrinth in Diprotodontian Marsupial Mammals: Diversity in Extant and Extinct Forms and Relationships with Size and Phylogeny". Journal of Mammalian Evolution. 20 (3): 191–198. doi:10.1007/s10914-013-9228-3. S2CID 16385939.
  2. ^ a b "XVI. On the fossil mammals of Australia.— Part I. Description of a mutilated skull of a large marsupial carnivore (Thylacoleo carnifex, Owen), from a calcareous conglomerate stratum, eighty miles S. W. Of Melbourne, Victoria". Philosophical Transactions of the Royal Society of London. 149: 309–322. 1859. doi:10.1098/rstl.1859.0016. S2CID 110651400.
  3. ^ a b Musser, Anne (29 November 2018). "Thylacoleo carnifex". Australian Museum. Retrieved 7 May 2019.
  4. ^ a b c "XV. On the affinities of thylacoleo". Philosophical Transactions of the Royal Society of London. 174: 575–582. 1883. doi:10.1098/rstl.1883.0015. ISSN 0261-0523. S2CID 111347165.
  5. ^ Gill, E.D. (25 February 1973). "Antipodal distribution of the holotype bones of Thylacoleo carnifex Owen (Marsupialia)". Science Reports of the Tohoku University. Second Series, Geology. 6: 497–499. Retrieved 13 August 2020.
  6. ^ Woods, J. T. (1956). "The skull of Thylacoleo carnifex". Memoirs of the Queensland Museum. 13: 125–140.
  7. ^ Bartholomai, Alan (1962). "A new species of Thylacoleo and notes on some caudal vertebrae of Palorchestes azael". Memoirs of the Queensland Museum. 14: 33–40.
  8. ^ a b Pledge, N.S. (1977). "A new species of Thylacoleo (Marsupialia: Thylacoleonidae) with notes on the occurrences and distribution of Thylacoleonidae in South Australia". Records of the South Australian Museum. 17: 277–283.
  9. ^ Long, J.A., Archer, M., Flannery, T. & Hand, S. (2002). Prehistoric Mammals of Australia and New Guinea - 100 million Years of Evolution. Baltimore: Johns Hopkins University Press. pp. 224pp.{{cite book}}: CS1 maint: multiple names: authors list (link)
  10. ^ Flannery, T.F.; Archer, M. (1984). "The macropodoids (Marsupialia) of the Early Pliocene Bow local fauna, central eastern New South Wales". The Australian Zoologist. 21: 357–383.
  11. ^ Pledge, Neville S. (1992). "The Curramulka local fauna: A new late Tertiary fossil assemblage from Yorke Peninsula, South Australia". The Beagle: Occasional Papers of the Northern Territory Museum of Arts and Sciences. 9: 115–142.
  12. ^ Naish, Darren (2004). "Of koalas and marsupial lions: the vombatiform radiation, part I". Molecular Phylogenetics and Evolution. 33 (1): 240–250. doi:10.1016/j.ympev.2004.05.004. PMID 15324852. Retrieved 17 October 2014.
  13. ^ Black, Karen; Price, Gilbert J; Archer, Michael; Hand, Suzanne J (2014). "Bearing up well? Understanding the past, present and future of Australia's koalas". Gondwana Research. 25 (3): 1186–201. Bibcode:2014GondR..25.1186B. doi:10.1016/j.gr.2013.12.008.
  14. ^ a b Black, K. H.; Archer, M.; Hand, S. J.; Godthelp, H. (2012). "The Rise of Australian Marsupials: A Synopsis of Biostratigraphic, Phylogenetic, Palaeoecologic and Palaeobiogeographic Understanding". In Talent, J. A. (ed.). Earth and Life. Springer Verlag. pp. 1040, 1047. doi:10.1007/978-90-481-3428-1_35. ISBN 978-90-481-3427-4.
  15. ^ Gillespie, Anna K; Archer, Michael; Hand, Suzanne J (2016). "A tiny new marsupial lion (Marsupialia, Thylacoleonidae) from the early Miocene of Australia". Palaeontologia Electronica. 19 (2). doi:10.26879/632.
  16. ^ Gillespie, Anna K.; Archer, Michael; Hand, Suzanne J. (2019-09-03). "Lekaneleo, a new genus of marsupial lion (Marsupialia, Thylacoleonidae) from the Oligocene–Miocene of Australia, and the craniodental morphology of L. roskellyae, comb. nov". Journal of Vertebrate Paleontology. 39 (5): e1703722. Bibcode:2019JVPal..39E3722G. doi:10.1080/02724634.2019.1703722. ISSN 0272-4634. S2CID 214332715.
  17. ^ a b Wroe, S; Myers, T. J; Wells, R. T; Gillespie, A (1999). "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". Australian Journal of Zoology. 47 (5): 489–98. doi:10.1071/ZO99006.
  18. ^ Wroe, Stephen; Myers, Troy; Seebacher, Frank; Kear, Ben; Gillespie, Anna; Crowther, Mathew; Salisbury, Steve (Summer 2003). "An alternative method for predicting body mass: the case of the Pleistocene marsupial lion". Paleobiology. 29 (3): 403–411. Bibcode:2003Pbio...29..403W. doi:10.1666/0094-8373(2003)029<0403:AAMFPB>2.0.CO;2. ISSN 0094-8373. Retrieved 14 August 2024 – via Cambridge Core.
  19. ^ a b Werdelin, L (1988). "Circumventing a Constraint - the Case of Thylacoleo (Marsupialia, Thylacoleonidae)". Australian Journal of Zoology. 36 (5): 565. doi:10.1071/ZO9880565. ISSN 0004-959X.
  20. ^ a b Wroe, S.; McHenry, C.; Thomason, J. (2005). "Bite club: Comparative bite force in big biting mammals and the prediction of predatory behaviour in fossil taxa". Proceedings of the Royal Society B: Biological Sciences. 272 (1563): 619–625. doi:10.1098/rspb.2004.2986. PMC 1564077. PMID 15817436.
  21. ^ a b Gillespie, Anna K. (2023-01-16). "Two new marsupial lion taxa (Marsupialia, Thylacoleonidae) from the early and Middle Miocene of Australia". Alcheringa: An Australasian Journal of Palaeontology. 47 (4): 506–521. Bibcode:2023Alch...47..506G. doi:10.1080/03115518.2022.2152096. ISSN 0311-5518. S2CID 256157821.
  22. ^ Wells, Roderick T.; Murray, Peter F.; Bourne, Steven J. (2009). "Pedal morphology of the marsupial lion Thylacoleo carnifex (Diprotodontia: Thylacoleonidae) from the Pleistocene of Australia". Journal of Vertebrate Paleontology. 29 (4): 1335–1340. Bibcode:2009JVPal..29.1335W. doi:10.1671/039.029.0424. S2CID 86460654.
  23. ^ "Discovery and Interpretation". Natural Worlds. Retrieved 7 May 2019.
  24. ^ Switek, Brian (31 August 2007). "Thylacoleo carnifex, ancient Australia's marsupial lion". Laelaps. Retrieved 8 May 2019.
  25. ^ a b c d Figueirido, Borja; Martín-Serra, Alberto; Janis, Christine M. (2016). "Ecomorphological determinations in the absence of living analogues: The predatory behavior of the marsupial lion (Thylacoleo carnifex) as revealed by elbow joint morphology" (PDF). Paleobiology. 42 (3): 508–531. Bibcode:2016Pbio...42..508F. doi:10.1017/pab.2015.55. hdl:1983/1f3ac566-0b08-48fb-b27c-63fe4256c138. S2CID 87168573.
  26. ^ "Extinct Marsupial Lion Tops African Lion In Fight To Death", Science Daily, 17 January 2008.
  27. ^ Dayton, Leigh (18 January 2008). "Marsupial lion was fast killer". The Australian. Archived from the original on 17 April 2009.
  28. ^ Wells, R.T.; Murray, P.F.; Bourne, S.J. (2009). "Pedal morphology of the marsupial lion Thylacoleo carnifex (Diprotodontia: Thylacoleonidae) from the Pleistocene of Australia". Journal of Vertebrate Paleontology. 29 (4): 1335–1340. Bibcode:2009JVPal..29.1335W. doi:10.1671/039.029.0424. S2CID 86460654.
  29. ^ a b Arman, Samuel D.; Prideaux, Gavin J. (15 February 2016). "Behaviour of the Pleistocene marsupial lion deduced from claw marks in a southwestern Australian cave". Scientific Reports. 6: 21372. Bibcode:2016NatSR...621372A. doi:10.1038/srep21372. PMC 4753435. PMID 26876952. S2CID 3548956.
  30. ^ a b c d Evans, A. R.; Wells, R. T.; Camens, A. B. (2018). "New skeletal material sheds light on the palaeobiology of the Pleistocene marsupial carnivore, Thylacoleo carnifex". PLOS ONE. 13 (12): e0208020. Bibcode:2018PLoSO..1308020W. doi:10.1371/journal.pone.0208020. PMC 6291118. PMID 30540785.
  31. ^ a b Switek, Brian. "Thylacoleo: Herbivore or Carnivore?". Wired.
  32. ^ a b c Horton, D. R.; Wright, R. V. S. (1981). "Cuts on Lancefield Bones: Carnivorous Thylacoleo, Not Humans, the Cause". Archaeology in Oceania. 16 (2): 73–80. doi:10.1002/j.1834-4453.1981.tb00009.x. JSTOR 40386545.
  33. ^ De Vis, C. W. (1883). "On tooth-marked bones of extinct marsupials". Proceedings of the Linnean Society of New South Wales. 8: 187–190. doi:10.5962/bhl.part.28646.
  34. ^ Anderson, C. (1929). "Palaeontological notes no. 1. Macropus titan Owen and Thylacoleo carnifex Owen". Records of the Australian Museum. 17: 35–49. doi:10.3853/j.0067-1975.17.1929.752.
  35. ^ Tyndale-Biscoe, Hugh (2005). Life of marsupials. Collingwood, Vic.: CSIRO. ISBN 978-0-643-09220-4.[page needed]
  36. ^ "Marsupial lion 'could climb trees'". BBC News. 2016-02-15.
  37. ^ Prideaux, Gavin J.; Long, John A.; Ayliffe, Linda K.; Hellstrom, John C.; Pillans, Brad; Boles, Walter E.; Hutchinson, Mark N.; Roberts, Richard G.; Cupper, Matthew L.; Arnold, Lee J.; Devine, Paul D.; Warburton, Natalie M. (January 2007). "An arid-adapted middle Pleistocene vertebrate fauna from south-central Australia". Nature. 445 (7126): 422–425. Bibcode:2007Natur.445..422P. doi:10.1038/nature05471. ISSN 0028-0836. PMID 17251978.
  38. ^ Case, J. A. (1985-01-01). "Differences in prey utilization by Pleistocene marsupial carnivores, Thylacoleo carnifex (Thylacoleonidae) and Thylacinus cynocephalus (Thylacinidae)". Australian Mammalogy. 8 (1): 45–52. doi:10.1071/AM85002. ISSN 0310-0049.
  39. ^ Hocknull, Scott A.; Lewis, Richard; Arnold, Lee J.; Pietsch, Tim; Joannes-Boyau, Renaud; Price, Gilbert J.; Moss, Patrick; Wood, Rachel; Dosseto, Anthony; Louys, Julien; Olley, Jon; Lawrence, Rochelle A. (2020-05-18). "Extinction of eastern Sahul megafauna coincides with sustained environmental deterioration". Nature Communications. 11 (1): 2250. Bibcode:2020NatCo..11.2250H. doi:10.1038/s41467-020-15785-w. ISSN 2041-1723. PMC 7231803. PMID 32418985.
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