The giant koala (Phascolarctos stirtoni) is an extinct arborealmarsupial which existed in Australia during the Pleistocene epoch. Phascolarctos stirtoni was about one-third larger than the contemporary koala, P. cinereus,[2] and has an estimated weight of 13 kg (29 lb), which is the same weight as a large contemporary male koala.[3]
Although considered a part of the Australian megafauna, its body mass excludes it from most formal definitions of megafauna. It is better described as a more robust koala, rather than a "giant"; in contrast, a number of Australian megafauna, such as Diprotodon and Procoptodon, were unambiguously giants, even if not compared to their closest relatives.
The two koala species co-existed during the Pleistocene, occupying the same arboreal niche.[2] The reason for the extinction of the larger of the two about 50,000 years ago is unknown, although there are various hypotheses for their extinction.
A description of the species was published by Alan Bartholomai in 1968, based on a partial maxilla with remains of teeth that was uncovered at the Cement Mills limestone quarry near Gore, Queensland. The material was determined to have occurred at a Pleistocene horizon of the site. The author assigned the species to the genus of the extant koala as Phascolarctos stirtoni, the specific epithet commemorates the American professor, R. A. Stirton, in recognition of his work on marsupial fossils.[1]
Descriptionedit
The giant koala was an arboreal marsupial weighing about 13 kg,[3] a little more than modern koalas. It is the largest known tree dwelling marsupial ever to have lived.[citation needed] Scientists say there is a clear similarity between the physical appearance of P. stirtoni and the modern koala.[4] It is assumed that the giant koala was a folivore which was specialised to feed on eucalyptus leaves, like its extant relative.
Extinctionedit
Fossil remains of Phascolarctos stirtoni have been discovered in Lake Eyre and Lake Tarkarooloo basins in South Australia.[5] It was once thought that the modern-day koala was descended from the giant koala, but this has now been determined to be incorrect. Gilbert Price, of the University of Queensland, used improved dating techniques to analyse fossils of both types of koala to find that the two species were living together in the same arboreal niche.[6] It is unclear from what the koalas descend, and why one species survived while the other became extinct. It is hypothesized that a change in climate and a restriction of food supply caused P. stirtoni's extinction. Another possible reason is hunting by humans, particularly for larger animals like P. stirtoni. The "dwarfing" hypothesis, based on the similarities of the two koalas has been used to support both ideas.[6]
Referencesedit
^ abBartholomai, Alan (1968). "A new fossil koala from Queensland and a reassessment of the taxonomie position of the problematical species, Koalemus ingens De Vis". Memoirs of the Queensland Museum. 15: 65–71.
^ ab. Archived from the original on 2007-09-26. Retrieved 2007-10-27.
^ abPrideaux, Gavin J.; Roberts, Richard G.; Megirian, Dirk; Westaway, Kira E.; Hellstrom, John C.; Olley, Jon M. (2007). "Mammalian responses to Pleistocene climate change in southeastern Australia" (PDF). Geology. 35 (1): 33. Bibcode:2007Geo....35...33P. doi:10.1130/G23070A.1.[permanent dead link]
^Design, Joy Williams—Artist Web. "JoyZine - Australian Megafauna: Giant Koala (Phascolarctos stirtoni)". www.artistwd.com.
^ ab"Scientists unlock secrets of Australia's giant 30kg koalas". Independent.co.uk. 4 January 2009.
Piper, Katarzyna J. (2005). "An Early Pleistocene Record of a Giant Koala (Phascolarctidae, Marsupalia) from Western Victoria" (PDF). Australian Mammalogy. 2 (27). CSIRO Publishing: 221–223. doi:10.1071/AM05221.
"Giant Koala Phascolarctos stirtoni". JoyZine. Art Web Design. Retrieved 1 December 2015.
Marks, Kathy (22 October 2011). "Scientists unlock secrets of Australia's giant 30kg koalas". Independent. Retrieved 2 December 2015.
April 15, 2024
giant, koala, giant, koala, phascolarctos, stirtoni, extinct, arboreal, marsupial, which, existed, australia, during, pleistocene, epoch, phascolarctos, stirtoni, about, third, larger, than, contemporary, koala, cinereus, estimated, weight, which, same, weight. The giant koala Phascolarctos stirtoni is an extinct arboreal marsupial which existed in Australia during the Pleistocene epoch Phascolarctos stirtoni was about one third larger than the contemporary koala P cinereus 2 and has an estimated weight of 13 kg 29 lb which is the same weight as a large contemporary male koala 3 Giant koalaTemporal range Late PleistoceneScientific classificationDomain EukaryotaKingdom AnimaliaPhylum ChordataClass MammaliaInfraclass MarsupialiaOrder DiprotodontiaFamily PhascolarctidaeGenus PhascolarctosSpecies P stirtoniBinomial name Phascolarctos stirtoniBartholomai 1968 1 Although considered a part of the Australian megafauna its body mass excludes it from most formal definitions of megafauna It is better described as a more robust koala rather than a giant in contrast a number of Australian megafauna such as Diprotodon and Procoptodon were unambiguously giants even if not compared to their closest relatives The two koala species co existed during the Pleistocene occupying the same arboreal niche 2 The reason for the extinction of the larger of the two about 50 000 years ago is unknown although there are various hypotheses for their extinction Contents 1 Taxonomy 2 Description 3 Extinction 4 ReferencesTaxonomy editA description of the species was published by Alan Bartholomai in 1968 based on a partial maxilla with remains of teeth that was uncovered at the Cement Mills limestone quarry near Gore Queensland The material was determined to have occurred at a Pleistocene horizon of the site The author assigned the species to the genus of the extant koala as Phascolarctos stirtoni the specific epithet commemorates the American professor R A Stirton in recognition of his work on marsupial fossils 1 Description editThe giant koala was an arboreal marsupial weighing about 13 kg 3 a little more than modern koalas It is the largest known tree dwelling marsupial ever to have lived citation needed Scientists say there is a clear similarity between the physical appearance of P stirtoni and the modern koala 4 It is assumed that the giant koala was a folivore which was specialised to feed on eucalyptus leaves like its extant relative Extinction editFossil remains of Phascolarctos stirtoni have been discovered in Lake Eyre and Lake Tarkarooloo basins in South Australia 5 It was once thought that the modern day koala was descended from the giant koala but this has now been determined to be incorrect Gilbert Price of the University of Queensland used improved dating techniques to analyse fossils of both types of koala to find that the two species were living together in the same arboreal niche 6 It is unclear from what the koalas descend and why one species survived while the other became extinct It is hypothesized that a change in climate and a restriction of food supply caused P stirtoni s extinction Another possible reason is hunting by humans particularly for larger animals like P stirtoni The dwarfing hypothesis based on the similarities of the two koalas has been used to support both ideas 6 References edit a b Bartholomai Alan 1968 A new fossil koala from Queensland and a reassessment of the taxonomie position of the problematical species Koalemus ingens De Vis Memoirs of the Queensland Museum 15 65 71 a b Parks South Australia Naracoorte Caves website Archived from the original on 2007 09 26 Retrieved 2007 10 27 a b Prideaux Gavin J Roberts Richard G Megirian Dirk Westaway Kira E Hellstrom John C Olley Jon M 2007 Mammalian responses to Pleistocene climate change in southeastern Australia PDF Geology 35 1 33 Bibcode 2007Geo 35 33P doi 10 1130 G23070A 1 permanent dead link Design Joy Williams Artist Web JoyZine Australian Megafauna Giant Koala Phascolarctos stirtoni www artistwd com http www artistwd com joyaustralia articles megafauna phascolarctos stirtoni php VmWMU7grKUk dead link a b Scientists unlock secrets of Australia s giant 30kg koalas Independent co uk 4 January 2009 Piper Katarzyna J 2005 An Early Pleistocene Record of a Giant Koala Phascolarctidae Marsupalia from Western Victoria PDF Australian Mammalogy 2 27 CSIRO Publishing 221 223 doi 10 1071 AM05221 Giant Koala Phascolarctos stirtoni JoyZine Art Web Design Retrieved 1 December 2015 Marks Kathy 22 October 2011 Scientists unlock secrets of Australia s giant 30kg koalas Independent Retrieved 2 December 2015 Retrieved from https en wikipedia org w index php title Giant koala amp oldid 1217321056, wikipedia, wiki, book, books, library,
