Wakaleo Temporal range: | |
---|---|
Life reconstruction of the type species, Wakaleo oldfieldi | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Infraclass: | Marsupialia |
Order: | Diprotodontia |
Family: | † Thylacoleonidae |
Genus: | † Wakaleo Clemens & Plane, 1974 [1] |
Type species | |
†Wakaleo oldfieldi Clemens & Plane, 1974 | |
Species | |
| |
Synonyms | |
|
Wakaleo (Diyari waka, "little", "small"; and Latin leo, "lion") [1] is an extinct genus of medium-sized thylacoleonids that lived in Australia in the Late Oligocene and Miocene Epochs.
Wakaleo was erected in 1974 by W. A. Clemens and M. Plane. [1] Five species are known:
Wakaleo is a genus of the thylacoleonid family of predatory mammals, which are known as marsupial lions. The size of Wakaleo species increases over the course of the evolution of the genus. W. schouteni is estimated to have weighed approximately 23 kilograms (51 lb), comparable to a dog, [3] while W. vanderleueri and W. alcootaensis are estimated to have had bodymasses of 30 kilograms (66 lb) and 50 kilograms (110 lb). [4]
The first description was given in an examination of material discovered at Alcoota in the Northern Territory of Australia. The holotype was a single fossil maxilla fragment [5] found in 1974 by the palaeontologist Michael Archer.
Fossil material of this species is fragmentary and rare, and it is only known amongst the Alcoota local fauna. Further evidence of the animals cranial and dental features were examined in 2014, leading to a revision of Wakaleo alcootaensis that provided further support to the separation from earlier Wakaleo species. [6]
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 . As with Thylacoleo carnifex , this species is presumed to have used its maxillary (upper) teeth to hold its food and sharpen the mandibular teeth, the latter were also used in slicing and stabbing during eating. The premolars also had a crescent-shaped circumference for slicing. [7]
The description by Rauscher was published in 1987, naming a new species and genus as Priscileo pitikantensis. [2] The designation as the type species of the genus Priscileo was later recognised as a species of a revised description of Wakaleo . [3] Fossil material examined by Rauscher was obtained at Lake Pitikanta, situated to the east of Lake Eyre. [2]
The smallest known species of Wakaleo, it lived in Australia about 25 million years ago, from the late Oligocene to middle Miocene, and was approximately the size of a cat. They were mid-sized predators who probably hunted in trees or ambushed prey from a branch. Like the later discovery, Wakaleo schouteni , the species possesses three premolars and four molars which distinguishes them from others of the genus. A little smaller than W. schouteni, this species also differs in the morphology of the humerus. [3]
It is known only from a few post cranial bones and a poorly preserved maxillary fragment found at the Lake Pitikanta site of the Lake Ngapakaldi to Lake Palankarinna Fossil Area in northeastern South Australia. To date W. pitikantensis, Wakaleo schouteni and "Priscileo' roskellyae are the most ancient phylogenies of the Thylacoleonidae and presumed to have diverged during the early to middle Oligocene epoch. [3]
The description of the species was published in 2017, the collaborating authors Anna Gillespie, Mike Archer and Suzanne Hand working on the PANGEA research project based at the University of New South Wales. The holotype is a largely complete skull retaining some teeth and alveoli, with other materials such as the lower jaw and a humerus associated with the new species as paratypes. The discovery of more complete evidence of Oligocene species of the marsupial lion lineages prompted the authors to emend the circumscription of Wakaleo to include the type species of another genus, Priscileo pitikantensis , as a sister species to this taxon and contradicting a 2016 study that supported separation of P. pitikantensis from the wakaleo clade. Another early thylacoleonid species, "Priscileo" roskellyae , was determined to have diverged from this genus during early period of the fossil record, and scant evidence of the species did not allow revising authors to assign a taxonomic placement with any confidence. [3]
A painter celebrated for his reconstructions of ancient animals, Peter Schouten, was honored by the authors in their proposed epithet for the species. [3]
A species assigned to Wakaleo and resembling a contemporary animal of the Oligocene, Wakaleo pitikantensis. They were mid-sized predators who probably hunted in trees or ambushed prey from a branch. Calculations of the size following a method of statistical analysis for predicting body size, derived from 164 millimetres for the greatest length of the skull, indicate a weight of 22.6 or 24.0 kilograms. [3] [8] Another estimate using regression equations previously used in calculations of body size for Thylacoleo carnifex , a very large carnivore, resulted in a value around 5 kg that the describing authors considered too small. [9] The dentition suggests that W. schouteni may have been omnivorous, but reveals the transition to hyper-carnivory of the genus during the Miocene. [3]
The distribution of the species included the Riversleigh World Heritage Area in the northwest of Queensland, at sediments dated to the later Oligocene to early Miocene. The assumption of at least partially arboreal habits is by the forest types that existed during the Oligo-Miocene at Riversleigh, open woodlands with the later development of rainforest. The humerus morphology is proposed to support this conception as a scansorial and arboreal predator, being similar to the structures of the arm and shoulder in species such as Phascolarctos cinereus , the related koala, and spotted cuscus Spilocuscus maculatus . [3]
The type species fossils were originally found in the Bullock Creek (Northern Territory) area. It has been found in limestone deposits in Riversleigh. [10]
The first fossil, a right dentary fragment, was found in 1967 by a group of field workers at Bullock Creek in the Northern Territory. A left dentary of the species in a good state of preservation was described in 1896. [11] Since then more fossils have been recovered, including a well-preserved near-complete cranium with the mandible intact. [10]
The various species of Wakaleo are thought to have been carnivores. [12] Later species of Wakaleo show increased adaptation to terrestrial locomotion (as opposed to the arboreal lifestyle of earlier species), and to grappling prey with their forelimbs, [13] likely correlated with increasing prey size. [6] [3]
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".
Bandicoots are a group of more than 20 species of small to medium sized, terrestrial, largely nocturnal marsupial omnivores in the order Peramelemorphia. They are endemic to the Australia–New Guinea region, including the Bismarck Archipelago to the east and Seram and Halmahera to the west.
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 marsupials from the order Dasyuromorphia. The only species to survive into modern times was the thylacine, which became extinct in 1936.
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.
Baru, sometimes referred to as the cleaver-headed crocodile, is an extinct genus of Australian mekosuchine crocodilian. Its fossils have been found from various Late Oligocene and Miocene localities from across the Northern Territory and Queensland, indicating that Baru was a common genus during the late Paleogene and early Neogene. Three species are recognized, B. darrowi, B. iylwenpeny, and B. wickeni.
The Alcoota Fossil Beds are an important paleontological Lagerstätte in the Northern Territory of Australia located on Alcoota Station in the locality of Anmatjere about 115 kilometres (71 mi) north-east of Alice Springs in the Central Australia region. It is notable for the occurrence of well-preserved, rare, Miocene vertebrate fossils, which provide evidence of the evolution of the Northern Territory’s fauna and climate. The Alcoota Fossil Beds are also significant as a research and teaching site for palaeontology students.
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.
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.
Ekaltadeta is an extinct genus of marsupials related to the modern musky rat-kangaroos. Ekaltadeta was present in what is today the Riversleigh formations in Northern Queensland from the Late Oligocene to the Miocene, and the genus includes three species. The genus is hypothesized to have been either exclusively carnivorous, or omnivorous with a fondness for meat, based on the chewing teeth found in fossils. This conclusion is based mainly on the size and shape of a large buzz-saw-shaped cheek-tooth, the adult third premolar, which is common to all Ekaltadeta.
The genus Nimbacinus contains two species of carnivorous, quadrupedal marsupials in Australia both of which are extinct:
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.
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 during 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.
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.
Cookeroo is a genus of extinct kangaroos from the Late Oligocene and Early Miocene found in fossil deposits from the Riversleigh World Heritage Area, in Australia. The genus includes two species, C. bulwidarri and C. hortusensis.
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 is a fossil genus 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.