|Family:||† Thylacoleonidae |
Thylacoleonidae is a family of extinct meat-eating 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 Pleistocene, with some species the size of a possum and others as large as that of a leopard. As a whole, they were largely arboreal, in contrast to the mostly terrestrial dasyuromorphs (quolls only recently took the niches vacated by small thylacoleonids), monitor lizards and mekosuchines.
Hypercarnivory was also found in another order of marsupials, the dasyuromorph family Thylacinidae that included the Tasmanian tiger Thylacinus cynocephalus that became extinct in the twentieth century.
A diprotodontian family allied to the Vombatiformes, mammals that radiated and diversified in the Oligocene to Miocene. The thylacoleonid genera exhibit specialised dentition that allowed them to kill prey larger than themselves.
The earliest descriptions of the most recent species recognise the secateur-like blades of the teeth as a powerful mammalian predator, a "marsupial lion," that were noted as missing in the Australian environment. The third premolars exhibit this blade-like development, becoming greatly enlarged in the Pleistocene species Thylacoleo carnifex , prompting the description by Owen as "…one of the fellest and most destructive of predatory beasts."They are seen as presumably occupying a trophic level as peak predators in their local ecologies, some smaller and arboreal climbers while those terrestrial species are sizably comparable to large dog or a big cat.
The genera are associated with the late Oligocene and Miocene epochs. Microleo and Wakaleo have been located at the Lake Pitikanta fossil area in Central Australia and toward the northern coast at Riversleigh, below the gulf of Carpentaria, a rich source of fossil fauna. The most recent species, Thylacoleo carnifex, existed at least until the Pleistocene, the earliest known specimens of the family are dated to around twenty five million years ago.
The family was described by Theodore Gill in a systematic revision of mammalian taxa published by the Smithsonian Institution in 1872.The name is derived from the genus named by Richard Owen, Thylacoleo , which he recognised as a potent carnivore and described as marsupial version of the modern lions (Leo).
They are now thought to be allied with the Vombatiformes, still represented in the modern Australian fauna by koalas and wombats. They appear to have diverged by specialising in a carnivorous diet in the early Oligocene, and increased in size along with their prey during the Miocene.[ citation needed ]
A revision of the family was published in 2017, enabled by the discovery of a skull of an early species, named as Wakaleo schouteni , which allowed closer comparison with previously described species and the more complete fossil record of the lineages. The study by Anna Gillespie, Mike Archer and Suzanne Hand, revised the description of Wakaleo to include a new species and circumscribe taxa previously assigned to Priscileo .
Five genera are currently accepted as belonging to this family:
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 order Peramelemorphia includes the bandicoots and bilbies; it equates approximately to the mainstream of marsupial omnivores. All members of the order are endemic to the twin land masses of 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 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 five 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.
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.
Thylacinidae is an extinct family of carnivorous, superficially dog-like marsupials from the order Dasyuromorphia. The only species to survive into modern times was the thylacine, which became extinct in 1936.
Megalania is an extinct species of giant monitor lizard, part of the megafaunal assemblage that inhabited Australia during the Pleistocene. It is the largest terrestrial lizard known to have existed, reaching an estimated length of 3.5 to 7 metres, and weighing between 97–1,940 kg (214–4,277 lb), but the fragmentary nature of known remains make estimates highly uncertain.
Phascolarctos is a genus of marsupials with one living 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. Some of these marsupial lions were the largest mammalian predators in Australia of their time, with Thylacoleo carnifex approaching the weight of a lioness. The estimated average weight for the species ranges from 101 to 130 kg.
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.
Ekaltadeta is an extinct genus of marsupials related to the modern musky rat-kangaroos. Ekaltadelta was present in what is today the Riversleigh formations in Northern Queensland from the Late Oligocene to the Miocene.
Wakaleo oldfieldi is an extinct species of marsupial lions of the genus Wakaleo, found in Miocene deposits of South Australia. It had three unfused molar teeth instead of two fused molars as is the case with the Pleistocene Thylacoleo carnifex.
Wakaleo pitikantensis is a species of carnivorous marsupial that was discovered at fossil sites in South Australia.
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.
Microleo attenboroughi is a very small species of the Thylacoleonidae family of marsupials from the Early Miocene of Australia, living in the wet forest that dominated Riversleigh about 18 million years ago. The genus Microleo is currently known from a broken palate and two pieces of jaw, containing some teeth and roots that correspond to those found in other species of thylacoleonids. The shape and structure of the blade-like P3 tooth, a premolar, distinguished the species as a new genus. It was found in Early Miocene-aged deposits of the Riversleigh fossil site in Queensland, regarded as one of the most significant palaeontological sites yet discovered, and named for the naturalist David Attenborough in appreciation of his support for its heritage listing. The anatomy of Microleo suggests the genus is basal to all the known thylacoleonids, known as the marsupial lions, although its relative size prompted one discoverer to describe it as the "feisty" kitten of the family.
Riversleigh fauna is the collective term for any species of animal identified in fossil sites located in the Riversleigh World Heritage Area.
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.
Wakaleo schouteni is a species of carnivorous marsupial that was discovered at fossil sites in South Australia.
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.