Phascolarctos

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Phascolarctos
Koala climbing tree.jpg
A koala (Phascolarctos cinereus) climbing a tree in Otway National Park, Victoria, Australia
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Infraclass: Marsupialia
Order: Diprotodontia
Family: Phascolarctidae
Genus: Phascolarctos
Blainville, 1816
Type species
Lipurus cinereus
Goldfuss, 1817 [1]
Species
Synonyms [2]
  • DraximenusAnonymous, 1829
  • Draximenus Lay, 1825
  • Koala Schinz, 1821
  • KolaGray, 1821
  • Lipurus Goldfuss, 1817
  • LiscurusMcMurtrie, 1834
  • MorodactylusGoldfuss, 1820
  • PhascolarctusBrookes, 1828

Phascolarctos is a genus of marsupials with one extant species, the koala Phascolarctos cinereus , an iconic animal of Australia. Several extinct species of the genus are known from fossil material, these were also large tree dwellers that browsed on Eucalyptus leaves.

Contents

Taxonomy

The genus was named by French zoologist Henri Marie Ducrotay de Blainville in 1816. [3] [4]

The type species, the modern koala, was named as Lipurus cinereus by G. A. Goldfuss in 1817, later combined as Phascolarctos cinereus. [5] Goldfuss published this name with a reproduction of John Lewin's 1803 illustration of the species in New South Wales.

An accepted synonymy of other generic names referring to Phascolarctos was published in 1988. [6] The koala is listed in national conservation legislation as "Phascolarctos cinereus (combined populations of Qld, NSW and the ACT)", previously determined in 2012 to be "a species for the purposes of the EPBC act 1999" (EPBC). [7] The koala was classified as Least Concern on the Red List, and reassessed as Vulnerable in 2014. [8]

The name is derived from Ancient Greek φάσκωλος (phaskolos), referring to a leather pouch or bag, and ἄρκτος (arktos), meaning "bear". [9]

Description

Phascolarctos is a genus of large arboreal marsupials that has specialised in leaves of Eucalyptus, a poor quality and potentially toxic food source that is unavailable to most other native mammals. [10] The extinct species are presumed to have similar diet and habits to the modern koala, the largest Australian folivore, which was exceeded in size by the even more robust P. stirtoni. [11] The tail of koalas is almost absent, an unusual characteristic for a tree climbing mammal, although other anatomical features are well suited to that habitat. They have some resemblance to the wombats, a family of large terrestrial marsupials which are allied with koalas as Vombatiformes. [10]

The fossil material referred to the extinct species of this genus is scarce and fragmentary. Some remains are tentatively referred to Phascolarctos stirtoni, and the specimen for Phascolarctos maris, a partial lower molar, was later suggested by Karen H. Black to be an example of variance within the P. stirtoni species. [12]

Distribution

Phascolarctos species have been discovered as fossil remains in several regions across southern and eastern Australia, in South Australia, Queensland and Victoria, and still occurs in those states and New South Wales. The modern koala is also known in the fossil record of the southwest of Australia and many other regions, but no occurrence of a living or extinct Phascolarctos species is recorded in the states of Tasmania and the Northern Territory. [11]

The existing koala P. cinereus once had a wide range across the continent, which substantially contracted as a consequence of climatic changes that included extremes such as glacial cycles. Extinction of regional populations includes their disappearance from Western Australia after the mid to late Pleistocene, where their previous success is indicated by numerous fossils discovered in the Leeuwin-Naturaliste region. The disappearance from Southwest Australia coincided with a change in the region's fire regimes. [11]

The temporal range of the Phascolarctus species includes fossils dated to the early Pliocene and mid to late Pleistocene. [12] The earliest record of P. cinereus, the only species of the modern era, is dated to around 350 000 years ago. Phascolarctus is a remnant of a family that includes eight to ten genera, the Phascolarctidae, which diverged around 26 million years ago (during the Oligocene epoch). [11]

The records for Phascolarctos yorkensis (Pledge, 1992) include occurrences in Curramulka Local Fauna in South Australia and Wellington Caves in New South Wales, possibly datable to the late Miocene. [11]

Classification

Phascolarctos gives its name to the Phascolarctidae family, which allies a number of other genera that are now extinct. Anatomical similarities suggest the probably share a common ancestor of Vombatidae, represented by the living species of Vombatus and Lasiorhinus ; the wombats are their closest extant relations among the Diprotodontia order of marsupials. [10]

Family Phascolarctidae [13]

A previously recognised arrangement of infraspecific taxa may be summarised as

Three subspecies have been recognised within the existing species, based on specimens collected in Queensland, New South Wales and a "southern race" in Victoria. These may only represent clinal variation within the species at different latitudes, [19] a conclusion reached by a genomic comparison in 2019 that found no support for a classification as three subspecies; the study instead supports a proposal for the population be recognised as a single evolutionary significant unit for conservation purposes. [20]

Related Research Articles

<span class="mw-page-title-main">Koala</span> Arboreal herbivorous marsupial native to Australia

The koala, sometimes called the koala bear, is an arboreal herbivorous marsupial native to Australia. It is the only extant representative of the family Phascolarctidae and its closest living relatives are the wombats. The koala is found in coastal areas of the mainland's eastern and southern regions, inhabiting Queensland, New South Wales, Victoria, and South Australia. It is easily recognisable by its stout, tailless body and large head with round, fluffy ears and large, dark nose. The koala has a body length of 60–85 cm (24–33 in) and weighs 4–15 kg (9–33 lb). Fur colour ranges from silver grey to chocolate brown. Koalas from the northern populations are typically smaller and lighter in colour than their counterparts further south. These populations possibly are separate subspecies, but this is disputed.

<span class="mw-page-title-main">Diprotodontia</span> Order of marsupial mammals

Diprotodontia is the largest extant order of marsupials, with about 155 species, including the kangaroos, wallabies, possums, koala, wombats, and many others. Extinct diprotodonts include the hippopotamus-sized Diprotodon, and Thylacoleo, the so-called "marsupial lion".

<span class="mw-page-title-main">Peramelemorphia</span> Order of mammals

The order Peramelemorphia includes the bandicoots and bilbies. All members of the order are endemic to Australia-New Guinea and most have the characteristic bandicoot shape: a plump, arch-backed body with a long, delicately tapering snout, very large upright ears, relatively long, thin legs, and a thin tail. Their size varies from about 140 grams up to 4 kilograms, but most species are about one kilogram.

<span class="mw-page-title-main">Phascolarctidae</span> Family of marsupials

The Phascolarctidae is a family of marsupials of the order Diprotodontia, consisting of only one extant species, the koala, and six well-known fossil species, with another six less well known fossil species, and two fossil species of the genus Koobor, whose taxonomy is debatable but are placed in this group. The closest relatives of the Phascolarctidae are the wombats, which comprise the family Vombatidae.

<span class="mw-page-title-main">Vombatiformes</span> Suborder of marsupials

The Vombatiformes are one of the three suborders of the large marsupial order Diprotodontia. Seven of the nine known families within this suborder are extinct; only the families Phascolarctidae, with the koala, and Vombatidae, with three extant species of wombat, survive.

<i>Thylacoleo</i> Extinct genus of marsupials

Thylacoleo is an extinct genus of carnivorous marsupials that lived in Australia from the late Pliocene to the Late Pleistocene, 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.

<span class="mw-page-title-main">Giant koala</span> Extinct species of marsupial

The giant koala 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, and has an estimated weight of 13 kg (29 lb), which is the same weight as a large contemporary male koala.

<i>Palorchestes</i> Extinct genus of marsupial

Palorchestes is an extinct genus of large terrestrial, herbivorous Australian marsupial of the family Palorchestidae, living from the Miocene through to the Late Pleistocene. Like other palorchestids, it had highly retracted nasal region suggesting that it had a prehensile lip, as well as highly unusual clawed forelimbs that were used to grasp vegetation.

<i>Wakaleo</i> Extinct genus of marsupials

Wakaleo is an extinct genus of medium-sized thylacoleonids that lived in Australia in the Late Oligocene and Miocene Epochs. Although much smaller than its close relative, the marsupial lion, Wakaleo would have been a successful hunter. It had teeth specially designed for cutting and stabbing. The genus is from an extinct family of Vombatiformes, so it is distantly related to the herbivorous wombats.

<span class="mw-page-title-main">Riversleigh rainforest koala</span> Extinct species of marsupial

The Riversleigh rainforest koala is an extinct marsupial, closely related to the extant koala, that inhabited northwestern Queensland in the early-middle Miocene. It is the only species assigned to the genus Nimiokoala. Along with species of sister genus Litokoala, the Riversleigh rainforest koala is the smallest representative of family Phascolarctidae. Based on cladistic analysis, Nimiokoala is one of the more basal genera of Phascolarctide. It died out due to climate change rendering the environment more arid. It probably had a more generalized diet than that of the modern species, but its exact food preferences are unknown.

<i>Propleopus</i> Extinct genus of marsupials

Propleopus is an extinct genus of marsupials. Three species are known: P. chillagoensis from the Plio-Pleistocene, and P. oscillans and P. wellingtonensis from the Pleistocene. In contrast to most other kangaroos, and similar to their small extant relative, the musky rat-kangaroo, they were probably omnivorous.

<i>Litokoala</i> Extinct genus of marsupials

Litokoala is an extinct genus of marsupials, and along with Nimiokoala, is closely related to the modern koala. The three genera may have diverged at an earlier date, although the drying of the continent and the expansion of Eucalyptus forests towards the late Miocene may have delayed the evolution of cranial features unique to the modern genera. This indicates that either fossil genus could be an ancestor of the modern genus, or the modern genus has a common ancestor to both. More material needs collection to improve their taxonomical relationships.

The Macropodidae are an extant family of marsupial with the distinction of the ability to move bipedally on the hind legs, sometimes by jumping, as well as quadrupedally. They are herbivores, but some fossil genera like Ekaltadeta are hypothesised to have been carnivores. The taxonomic affiliations within the family and with other groups of marsupials is still in flux.

Invictokoala monticola is an extinct phascolarctid marsupial mammal from the middle Pleistocene of central-eastern Queensland, Australia. The holotype was found during cave excavations at Mount Etna. It was first named by Gilbert J. Price and Scott A. Hocknull in 2011.

Macropus pearsoni is an extinct Australian vertebrate species belonging to the family Macropodidae, and is in the same genus (Macropus) as extant kangaroos. M. pearsoni lived during the Pleistocene. It is known from fossil mandibles collected from Pleistocene beds from the Darling Downs in New South Wales, Lake Kanunka in northeastern South Australia, and the Cape York Peninsula. it reached a size similar to Macropus titan, which is a mass of 150 kg.

Priscakoala is an extinct genus of koala from the Early Miocene of Riversleigh, Australia. It has one species: Priscakoala lucyturnbullae.

Perikoala is an extinct genus of marsupials, related to the modern koala. The genus diverged from a common ancestor of the other koala genera Nimiokoala, Litokoala, and Phascolarctos, which contains the living koala.

Ngapakaldia is an extinct genus of diprotodontid marsupials, related to the modern koala and wombat. Around the size of a sheep, it was a ground-dwelling herbivore that lived around the vegetated shores of lakes in Central Australia during the Late Oligocene.

Riversleigh fauna is the collective term for any species of animal identified in fossil sites located in the Riversleigh World Heritage Area.

Madakoala is a genus of extinct phascolarctid marsupials with three known species, Madakoala devisi,Madakoala wellsiandMadakoala robustus. It is allied to extinct genera Invictokoala, Koobor, Litokoala, Nimiokoala, Perikoala, Phascolarctos and Priscakoala, along with Phascolarctos, the genus of the existing koala. Madakoala went extinct around 280,000 years ago in the Pleistocene epoch. They are known to exist by limited cranial material in fossils, so the existence of some of the subspecies is questionable because of missing dental data.

References

  1. ↑ Goldfuss, G.A. 1817. In Schreber, J.C.D. von (1774–1855). Die Säugethiere, in Abbildungen nach der Natur, mit Beschreibungen. Fortgesetzt von A. Goldfuss . 65e cahier. [pl. 155 Aa Bb]
  2. ↑ "Phascolarctos". Global Biodiversity Information Facility . Retrieved 1 August 2021.
  3. ↑ de Blainville, Henri (1816). "Prodrome d'une nouvelle distribution systématique du règne animal". Bulletin de la Société Philomáthique, Paris (in French). 8: 113–124.
  4. ↑ "Genus Phascolarctos Blainville, 1816". Australian Faunal Directory. 6 October 2017. Archived from the original on 15 January 2021. Retrieved 2023-02-17.
  5. ↑ In Schreber, J.C.D. von (1774–1855). Die Säugethiere, in Abbildungen nach der Natur, mit Beschreibungen. Fortgesetzt von A. Goldfuss. 65e cahier. [pl. 155 Aa Bb].
  6. ↑ McKay, G.M. 1988. Phascolarctidae. pp. 51-52 in Walton, D.W. (ed.). Zoological Catalogue of Australia Volume 5. Mammalia. Canberra : Australian Government Publishing Service x 274 pp.
  7. ↑ Determination that a distinct population of biological entities is a species for the purposes of the Environment Protection and Biodiversity Conservation Act 1999 (Cth) (132)
  8. ↑ Woinarski, J.; Burbidge, A.A. (2020). "Phascolarctos cinereus". IUCN Red List of Threatened Species . 2020: e.T16892A166496779. doi: 10.2305/IUCN.UK.2020-1.RLTS.T16892A166496779.en . Retrieved 12 November 2021.
  9. 1 2 3 4 5 Talent, John A. (2012). Earth and Life. Springer. p. 1047. ISBN   9789048134281.
  10. 1 2 3 Hall, L.S. (1983). "Koala". In Strahan, R. (ed.). Complete book of Australian mammals. The national photographic index of Australian wildlife . London: Angus & Robertson. pp. 112–113. ISBN   0207144540.
  11. 1 2 3 4 5 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.
  12. 1 2 3 K J Piper. 2013 An early Pleistocene record of a giant koala (Phascolarctidae: Marsupialia) from western Victoria. Australian Mammalogy 27(2) 221–223
  13. ↑ Groves, C. P. (2005). "Family Phascolarctidae". In Wilson, D. E.; Reeder, D. M (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. p. 43. ISBN   978-0-8018-8221-0. OCLC   62265494.
  14. ↑ Gilbert J. Price and Scott A. Hocknull (2011). "Invictokoala monticola gen. et sp. nov. (Phascolarctidae, Marsupialia), a Pleistocene plesiomorphic koala holdover from Oligocene ancestors". Journal of Systematic Palaeontology. 9 (2): 327–335. doi:10.1080/14772019.2010.504079. S2CID   84316375.
  15. ↑ N. S. Pledge. 1987. Phoscolarctos maris, A new species of koala (Marsupialia: Phascolarctidae) from the Early Pliocene of South Australia. Possums and Opossums: Studies in Evolution 1:327-330
  16. ↑ 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.
  17. ↑ Karen Black; et al. (2012). "New Tertiary koala (Marsupialia, Phascolarctidae) from Riversleigh, Australia, with a revision of phascolarctid phylogenetics, paleoecology, and paleobiodiversity". Journal of Vertebrate Paleontology. 32 (1): 125–138. Bibcode:2012JVPal..32..125B. doi:10.1080/02724634.2012.626825. S2CID   86152273.
  18. ↑ Thomas, Oldfield (1923). "On some Queensland Phalangeridae". Annals and Magazine of Natural History. 9 (11): 246–250. doi:10.1080/00222932308632848.
  19. ↑ Jackson, Stephen M. (2010). "Family PHASCOLARCTIDAE". Australian Faunal Directory . Retrieved 13 February 2022.
  20. ↑ Kjeldsen, S.R., Raadsma, H.W., Leigh, K.A. et al. Genomic comparisons reveal biogeographic and anthropogenic impacts in the koala (Phascolarctos cinereus): a dietary-specialist species distributed across heterogeneous environments. Heredity 122, 525–544 (2019).
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