|Non-Thylacinus thylacinids, including Nimbacinus (top right)|
|Family:||† Thylacinidae |
C.L. Bonaparte, 1838
All extinct, see text
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 (Thylacinus cynocephalus), which became extinct in 1936.
The consensus on placement of the family is with the Dasyuromorphia order, with agreement on the divergence this family and the Dasyuridae, represented by the extant quolls and Tasmanian devil Sarcophilus harrisii , remaining under consideration.
The thylacinid family was represented by two species in a synonymy published in 1982, the recently extinct Tasmanian tiger and the species Thylacinus potens , known by fossil material. Discoveries of new material, especially in well researched fossil depositions at the Riversleigh World Heritage Area, revealed a diverse array of genera and families existing during Miocene epoch. The dentition of specimens and some largely complete crania showed the development of specialist predators capable of hunting and consuming a range of vertebrate species, and like other mammalian predators, such as the canid family, could include herbivores larger than themselves. An assessment of the size range of the species has provided evidence of animals occupying a greater number of trophic levels and challenged the conception of the dominance of reptilians as large hyper-carnivorous predators on the Australia continent.
The consensus of authors prior to 1982 was that the thylacinid family were related to the borhyaenidae, a group of South American predators, also extinct, that exhibited many similar characteristics of dentition. A review published in 1982 compared the skeletal structure of these groups, concluding the tarsal bones show greater affinity with the dasyurmorphs, strongly supporting the later theory that any dental similarities emerged independently.
Another family, the Thylacoleonidae, were also large carnivorous marsupials, but allied to the order Vombatiformes and assumed to have also evolutionarily converged as predators of large herbivores.
Family Thylacinidae, extinct
Dasyuromorphia is an order comprising most of the Australian carnivorous marsupials, including quolls, dunnarts, the numbat, the Tasmanian devil, and the thylacine. In Australia, the exceptions include the omnivorous bandicoots and the marsupial moles. Numerous South American species of marsupials are also carnivorous, as were some extinct members of the order Diprotodontia, including extinct kangaroos and thylacoleonids, and some members of the partially extinct clade Metatheria and all members of the extinct superorder Sparassodonta.
Thylacinus is a genus of extinct carnivorous marsupials from the order Dasyuromorphia. The only recent member was the thylacine, commonly also known as the Tasmanian tiger or Tasmanian wolf, which is believed to have become extinct in 1936. In the first half of the 20th century, an already dwindling thylacine population was exposed to a combination of excessive hunting by humans, as well as likely competition with introduced dogs. Other prehistoric species are known from this genus. An unidentified species is known from Pleistocene New Guinea. Thylacines emerged around four million years ago and were known to inhabit Australia before they disappeared, most likely due to competition with dingos. Their last known stronghold was in Tasmania before they became extinct due to European hunting.
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.
Nimbacinus dicksoni is an extinct thylacinid marsupial, a close relative of the recent but extinct thylacinid known as the Tasmanian tiger. It lived approximately 23-16 million years ago in the Miocene period. Nimbacinus dicksoni was about 1.6 ft (50 cm) long. Being a predator, it likely ate birds, small mammals, and reptiles. Like the recently-extinct thylacine, it may have been an awkward runner and used stamina to catch prey rather than speed. Fossils have been found in Australia at Riversleigh in north-western Queensland and Bullock Creek in the Northern Territory.
Thylacinus potens was the largest species of the family Thylacinidae, originally known from a single poorly preserved fossil discovered by Michael O. Woodburne in 1967 in a Late Miocene locality near Alice Springs, Northern Territory. It preceded the most recent species of thylacine by 4–6 million years, and was 5% bigger, was more robust and had a shorter, broader skull. Its size is estimated to be similar to that of a grey wolf; the head and body together were around 5 feet long, and its teeth were less adapted for shearing compared to those of the now-extinct thylacine.
Badjcinus turnbulli is an extinct thylacinid marsupial.
The genus Nimbacinus contains two species of carnivorous, quadrupedal marsupials in Australia both of which are extinct:
Thylacinus macknessi lived during the early Miocene and is the oldest known member of the genus Thylacinus. It is named after Brian Mackness, a supporter of Australian vertebrate paleontology.
Thylacinus megiriani lived during the late Miocene, 8 million years ago; the area T. megiriani inhabited in the Northern Territory was covered in forest with a permanent supply of water.
Maximucinus muirheadae is the largest known thylacinid species that lived in Queensland, Australia from the late Oligocene to the middle Miocene. The species was a quadrupedal marsupial predator, that in appearance looked similar to a dog with a long snout. Its molar teeth were specialized for carnivory; the cups and crest were reduced or elongated to give the molars a cutting blade. It is estimated to have weighed about 18 kilograms.
Muribacinus gadiyuli lived during the middle Miocene in Riversleigh. The species name comes from Wanyi aboriginal word for "little", in reference to its considerably small size compared to the modern thylacine and was similar in size to a fox-terrier dog, and "father" for the ancestral characteristics of the fossilised teeth.
Mutpuracinus archibaldi is an extinct carnivorous, quadrupedal marsupial that lived during the middle Miocene and is the smallest known thylacinid at approximately 1.1 kilograms, the size of a quoll, though, more closely related to the recently extinct thylacine.
Ngamalacinus timmulvaneyi lived during the early Miocene and has been found in Riversleigh.
Tyarrpecinus rothi is an extinct thylacinid marsupial that lived during the late Miocene and has been found at the Alcoota scientific reserve in the Northern Territory. The specific name honors Karl Roth for his contributions to the natural history of central Australia.
Wabulacinus ridei lived during the early Miocene in Riversleigh. It is named after David Ride, who made the first revision of thylacinid fossils. The material was found in system C of the Camel Spurtum assembledge.
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.
Riversleigh fauna is the collective term for any species of animal identified in fossil sites located in the Riversleigh World Heritage Area.
Joculusium muizoni is a fossil species discovered at the Riversleigh World Heritage Area. Little is known about the animal.
Thylacinus yorkellus is a fossil species of carnivorous marsupial, a sister species of the recently extinct Thylacinus cynocephalus, the Tasmanian tiger, both of which existed on mainland Australia.
William D. Turnbull (1922-2011) was an American paleontologist associated with the Chicago Field Museum. He published over 100 papers on mammals, continuing after his retirement as the museum's curator of mammals. He searched in Australia for evidence of recently extinct species, and made frequent expeditions to sites at the Washakie Formation in southwest Wyoming. His studies are considered significant contributions to the paleontology and biogeography of dinosaurs and Eocene mammals.