Neohelos Temporal range: Miocene, | |
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Skull of Neohelos stirtoni at the Melbourne Museum | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Infraclass: | Marsupialia |
Order: | Diprotodontia |
Family: | † Diprotodontidae |
Subfamily: | † Zygomaturinae |
Genus: | † Neohelos Stirton, 1967 |
Type species | |
Neohelos tirarensis Stirton, 1967 | |
Species | |
N. tirarensisStirton, 1967 Contents |
Neohelos is an extinct diprotodontid marsupial, that lived from the early to middle-Miocene. There are four species assigned to this genus, Neohelos tirarensis, the type species, N. stirtoni, N. solus and N. davidridei. N. davidridei is the most derived species of the genus, and its premolar morphology shows that it is structurally and ancestor of the genus Kolopsis . All four species are from the Bullock Creek in the Northern Territory and Riversleigh of Australia.
Neohelos is known from many specimens, assigned to all the species. N. tirarensis includes a partial skull, premaxillas, maxillas, teeth, and dentarys; N. solus is known from a maxilla and dentary; N. davidridei includes teeth and a maxilla fragment; and N. stirtoni is known from a mostly complete skull, a maxilla and a dentary. [2]
A revision of Neohelos found a set of features in all the species that are absent in all other diprotodontoids. They are listed below: [2]
Neohelos includes many species. Among them, N. davidridei is the most derived. N. davidridei shows many features that are also found in Kolopsis , and is thought to be the ancestor of it and its species. Together, Neohelos and Kolopsis make up Zygomaturinae along with Zygomaturus and other genera. [2]
Neohelos lived in the early to Middle Miocene of Queensland, Australia. It is one of a few diprotodont genera that existed in all three of Bullock Creek in the Northern Territory, Riversleigh in Queensland, and the Wipajiri Formation of South Australia. [2]
Obdurodon is a genus of extinct platypus-like Australian monotreme which lived from the Late Oligocene to the Late Miocene. Three species have been described in the genus, the type species Obdurodon insignis, plus Obdurodon dicksoni and Obdurodon tharalkooschild. The species appeared much like their modern day relative the platypus, except adults retained their molar teeth, and unlike the platypus, which forages on the lakebed, they may have foraged in the water column or surface.
Marsupial moles, the Notoryctidae, are highly specialized marsupial mammals, known from two species found at the Australian interior.
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.
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.
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.
Yalkaparidon is an extinct genus of Australian marsupials, first described in 1988 and known only from the Oligo-Miocene deposits of Riversleigh, northwestern Queensland, Australia.
Dromornis is a genus of large to enormous prehistoric birds native to Australia during the Oligocene to Pliocene epochs. The species were flightless, possessing greatly reduced wing structures but with large legs, similar to the modern ostrich or emu. They were likely to have been predominantly, if not exclusively, herbivorous browsers. The male of the largest species, Dromornis stirtoni, is a contender for the tallest and heaviest bird, and possibly exhibited aggressive territorial behaviour. They belong to the family Dromornithidae, extinct flightless birds known as mihirungs.
Quinkana is an extinct genus of mekosuchine crocodylians that lived in Australia from about 28 million to about 10,000 years ago. Most attributed specimens have been found in Queensland. It is speculated to have been one of the top predators of Pleistocene Australia.
Palorchestes is an extinct genus of terrestrial, herbivorous marsupials of the family Palorchestidae. The genus was endemic to Australia, living from the Miocene through to the Pleistocene epochs.
Wakaleo was a 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.
Wakaleo vanderleuri is a species of marsupial lion of the genus Wakaleo, that lived in Australia during the Miocene.
Barinya is a fossil genus from the marsupial family Dasyuridae, which contains the oldest known undoubted dasyurid.
Hulitherium tomasetti is an extinct zygomaturine marsupial that lived in New Guinea during the Pleistocene. The species name honours Berard Tomasetti, a Catholic priest in Papua New Guinea, who brought the fossils to the attention of experts.
Harpacochampsa is a poorly known Early Miocene crocodilian from the Bullock Creek lagerstätte of the Northern Territory, Australia. The current specimen consists of a partial skull and fragments of a long, slender snout reminiscent of that of a false gharial, demonstrating that it was a piscivore in life.
Raemeotherium is an extinct genus of diprotodont marsupial from the late Oligocene Namba Formation of South Australia. It was much smaller than other diprotodonts, approximately the size of a lamb, and comparatively gracile. It is usually placed within the Zygomaturinae, but because the upper third premolar is unknown doubt remains about its affinities.
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.
Yingabalanara is an extinct mammal from the Miocene of Australia. Known only from a few teeth, its affinities with other mammal groups remain unresolved.
Lekaneleo roskellyae is a fossil species of carnivorous marsupial that existed during the early Miocene in Australia. Once allied to the type species of the genus Priscileo, later placed as Wakaleo pitikantensis, "Priscileo" roskellyae was subsequently transferred to its own genus Lekaneleo.
Peradectes is an extinct genus of small metatherian mammals known from the latest Cretaceous to Eocene of North and South America and Europe. The first discovered fossil of P. elegans, was one of 15 Peradectes specimens described in 1921 from the Mason pocket fossil beds in Colorado. The monophyly of the genus has been questioned.