Nimbadon Temporal range: | |
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Composite N. lavarackorum skeleton from the Riversleigh site | |
N. lavarackorum mother and juvenile (reconstruction) by Peter Schouten | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Infraclass: | Marsupialia |
Order: | Diprotodontia |
Superfamily: | † Diprotodontoidea |
Genus: | † Nimbadon Hand, Archer, Godthelp, Rich & Pledge, 1993. [1] |
Species | |
†Nimbadon lavarackorum Contents |
Nimbadon is an extinct genus of marsupial, that lived from the Oligocene to the Miocene. [1] Many fossils have been found in the Riversleigh World Heritage property in north-western Queensland. It is thought to have an arboreal lifestyle. [2]
In 1990, skulls were unearthed in a previously unknown cave in the region. Researchers estimate that the first species of Nimbadon first appeared about 25 million years ago [1] and died out about 12 million years ago, perhaps from climate change-induced habitat loss.
Nimbadon lavarackorum is described as being koala-like. It is known from as many as 24 well-articulated specimens. The species was a tree-dweller, mainly feeding on stems and leaves. The feet and claws were large, being superficially similar to those of the koala. They retracted their claws when walking. [3]
While originally classified as a member of the family Diprotodontidae, a primarily terrestrial group, [1] [2] some later studies suggested a more basal position within the Diprotodontoidea. [4]
N. lavarackorum was an arboreal frugivore that primarily fed on C3 fruits. [5]
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".
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.
Australidelphia is the superorder that contains roughly three-quarters of all marsupials, including all those native to Australasia and a single species – the monito del monte – from South America. All other American marsupials are members of the Ameridelphia. Analysis of retrotransposon insertion sites in the nuclear DNA of a variety of marsupials has shown that the South American monito del monte's lineage is the most basal of the superorder.
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.
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.
Riversleigh World Heritage Area is Australia's most famous fossil location, recognised for the series of well preserved fossils deposited from the Late Oligocene to more recent geological periods. The fossiliferous limestone system is located near the Gregory River in the north-west of Queensland, an environment that was once a very wet rainforest that became more arid as the Gondwanan land masses separated and the Australian continent moved north. The approximately 100 square kilometres (39 sq mi) area has fossil remains of ancient mammals, birds, and reptiles of the Oligocene and Miocene ages, many of which were discovered and are only known from the Riversleigh area; the species that have occurred there are known as the Riversleigh fauna.
Thylacoleonidae is a family of extinct carnivorous diprotodontian marsupials from Australia, referred to as marsupial lions. The best known is Thylacoleo carnifex, also called the marsupial lion. The clade ranged from the Late Oligocene to the Late Pleistocene, with some earlier species the size of a possum, while the youngest members of the family belonging to the genus Thylacoleo reached sizes comparable to living big cats.
Wakaleo is an extinct genus of medium-sized thylacoleonids that lived in Australia in the Late Oligocene and Miocene Epochs.
Palorchestidae is an extinct family of vombatiform marsupials whose members are sometimes referred to as marsupial tapirs due to the retracted nasal region of their skulls causing them to superficially resemble those of true tapirs. The idea that they had a tapir-like trunk has been contested, with other authors contending that it is more likely that they had a prehensile lip and protrusible tongue instead. While earlier representatives like Propalorchestes had relatively unspecialsed forelimbs, the last member of the family, Palorchestes developed unusual clawed forelimbs with a morphology unlike that of any living animal, which were likely used to tear vegetation. They are suggested to have been browsers. The group experienced an increase in body size over time, with Propalorchestes weighing around 150 kilograms (330 lb), while the last known species, Palorchestes azael may have exceeded a ton. They are considered to be members of Diprotodontoidea, most closely related to the also extinct Diprotodontidae. Their closest living relatives are wombats.
Nimiokoala greystanesi 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, it 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.
Diprotodontidae is an extinct family of large herbivorous marsupials, endemic to Australia and New Guinea during the Oligocene through Pleistocene periods from 28.4 million to 40,000 years ago.
Warendja is an extinct genus of wombat. It is known from two species, W. encorensis from the Late Miocene Riversleigh site in Queensland, and W. wakefieldi known from the Pleistocene of South Australia, New South Wales, and Victoria. The two species are primarily distinguished by features of their enamel. It became extinct as part of the Quaternary extinction event. Warendja wakefieldi is estimated to have weighed about 10 kg, considerably smaller than living wombats. Warendja thought to be relatively basal amongst wombats, being the most primitive member to possess hypselodont cheek teeth. The morphology of the humerus of W. wakefieldi suggests that it engaged in scratch-digging.
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.
Naraboryctes philcreaseri is a fossil species of marsupial found at early Miocene deposits of Boodjamulla National Park of Riversleigh area, northwestern Queensland, Australia.
Malleodectes is an extinct genus of unusual marsupial, first discovered in 2011 at Riversleigh, Queensland, Australia.
Priscakoala is an extinct genus of koala from the Early Miocene of Riversleigh, Australia. It has one species: Priscakoala lucyturnbullae.
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.
Karen H. Black, born about 1970, is a palaeontologist at the University of New South Wales. Black is the leading author on research describing new families, genera and species of fossil mammals. She is interested in understanding faunal change and community structure in order to gain new understandings of past, current and future changes in biodiversity which are driven by climate.
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.