''Ekaltadeta'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

marsupial Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are natively found in Australasia, Wallacea, and the Americas. One of marsupials' unique features is their reproductive strategy: the young are born in a r ...

s related to the modern musky rat-kangaroos. ''Ekaltadeta'' was present in what is today the Riversleigh formations in Northern Queensland from the

Late Oligocene The Chattian is, in the geologic timescale The geologic time scale or geological time scale (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the pro ...

to the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

, and the genus includes three species. The genus is hypothesized to have been either exclusively

carnivorous A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose nutrition and energy requirements are met by consumption of animal tissues (mainly mu ...

, or

omnivorous An omnivore () is an animal that regularly consumes significant quantities of both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize ...

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''. Fossils of the animals include two near complete skulls, and numerous upper and lower jaws.

Taxonomy

The description of a new species and genus was published by Mike Archer and

Tim Flannery Timothy Fridtjof Flannery (born 28 January 1956) is an Australian mammalogist, palaeontologist, environmentalist, conservationist, explorer, author, science communicator Science communication encompasses a wide range of activities tha ...

in 1985. The type species is '' Ekaltadeta ima''. It was originally put within the family of

Potoroidae Potoroidae is a family of marsupials, small Australian animals known as bettongs, potoroos, and rat-kangaroos. All are rabbit-sized, brown, jumping marsupials and resemble a large rodent or a very small wallaby. Taxonomy The potoroids are s ...

, but like the musky rat-kangaroo, the genus was moved to the family Hypsiprymnodontidae. The diagnosis of the genus was revised in a 1996 study by

Stephen Wroe Stephen or Steven is an English first name. It is particularly significant to Christians, as it belonged to Saint Stephen ( ), an early disciple and deacon who, according to the Book of Acts, was stoned to death; he is widely regarded as the firs ...

of propleopine taxa, after new fossil specimens allowed for comparison with the type material and showcased new characteristics. A largely complete skull of ''E. ima'' was described by Wroe in 1998, prompting another reinvestigation of the propleonine clade which the author had suggested contained

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

and

polyphyletic A polyphyletic group is an assemblage that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies ...

species. The name ''Ekaltadeta'' is derived from two words in an indigenous language associated with the

McDonnell Ranges The MacDonnell Ranges, or Tjoritja in Arrernte, is a mountain range located in southern Northern Territory. MacDonnell Ranges is also the name given to an interim Australian bioregion broadly encompassing the mountain range, with an area of . ...

, combining the words for powerful, ''ekalta'', and ''eta'' to describe the "powerful tooth". The specific epithet ''ima'' means "condemned to die" in the language of the same people. The specific epithet ''jamiemulvaneyi'' refers to an honour given to J. Mulvaney as a supporter of the Riversleigh Society.

Distribution

A member of the exclusively Australian clade Hypsiprymnodontidae, all three species of ''Ekaltadeta'' are known exclusively from the

Riversleigh World Heritage Area 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 n ...

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

. The specimens used in the description of ''E. jamiemulvaneyi'' were obtained at two sites in this area, the "Encore" and "Cleft of Ages" sites. Both of these sites are dated to the end of the Middle or the beginning of the

late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million ye ...

References

{{Taxonbar, from=Q135402 Prehistoric macropods Oligocene mammals of Australia Miocene mammals of Australia Oligocene marsupials Miocene marsupials Prehistoric marsupial genera Fossil taxa described in 1985 Riversleigh fauna Diprotodonts

Taxonomy

Distribution

See also

References