''Australonycteris'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

and

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

genus of microchiropteran

bat Bats are mammals of the order Chiroptera.''cheir'', "hand" and πτερόν''pteron'', "wing". With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most bi ...

with the single species ''Australonycteris clarkae''. The species is known from fragmentary remains found at the

Murgon fossil site The Murgon fossil site is a paleontology, paleontological site of early Eocene age in south-eastern Queensland, Australia. It lies near the town of Murgon, some 270 km north-west of Brisbane. The Murgon site is important as the only site on ...

, in south-eastern

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

, dating to the early

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

, 54.6 million years ago. It is the oldest bat from the Southern Hemisphere and one of the oldest bats in the world, and inhabited forests and swampy areas, with a diet of insects and possibly small fish.

Taxonomy

A monotypic genus allied to the family

Archaeonycteridae Archaeonycteridae (formerly spelled Archaeonycterididae) is a Family (biology), family of extinct bats. It was originally erected by the Swiss people, Swiss naturalist Pierre Revilliod as Archaeonycterididae to hold the genus ''Archaeonycteris''. ...

, or classified by an indeterminate familial arrangement, describing

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

material collected at Murgon in 1994. The type specimen is a tooth. The material was discovered at the Tingamarra Local Fauna – Boat Mountain deposit, the type and only known location of fossil evidence of the species. The phylogenetic relationship to other

Chiroptera Bats are mammals of the Order (biology), order Chiroptera.''cheir'', "hand" and πτερόν''pteron'', "wing". With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in fli ...

is uncertain, but may represent an early geographic dispersal and separation from the

crown clade In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ...

of bat taxa found on other continents. The genus name is derived from ancient Greek, indicating a bat with an Australian distribution. The specific epithet honours Elaine Clark, a person closely associated with the palaeontological research at Riversleigh and Murgon.

Description

''Australonycteris clarkae'', one of the earliest bats in the fossil record, is known from several upper and lower teeth, an

edentulous Toothlessness, or edentulism, is the condition of having no teeth. In organisms that naturally have teeth, it is the result of tooth loss. Organisms that never possessed teeth can also be described as edentulous. Examples are the members of the ...

lower-jaw fragment, a partial periotic bone, and several postcranial fragments. It has a forearm length of , making it a medium-size bat species, and it could echolocate. ''Australonycteris'' displayed some differences in dental anatomy, compared to extant bats. Unlike other purported Eocene bats, such as the ''

Wyonycteris ''Wyonycteris'' is a genus of small mammals that existed in the late Paleocene and early Eocene epochs. The type species is '' Wyonycteris chalix'', which lived in Wyoming during the Clarkforkian North American Land Mammal Age of the Paleocene an ...

'' species of Wyoming and Europe in the northern hemisphere, ''Australonycteris clarkae'' possessed many of the anatomical characteristics of the modern

microchiropteran Microbats constitute the suborder Microchiroptera within the order Chiroptera (bats). Bats have long been differentiated into Megachiroptera (megabats) and Microchiroptera, based on their size, the use of echolocation by the Microchiroptera an ...

. The tooth tip of ''A. clarkae'' shows wear consistent with carrying prey with a hard carapace, such as beetles, or bony skeleton of fish; the body size of the species would make predation of fish at least possible. ''Australonycteris'' is thought to have been fully capable of flight.

References

* * {{Taxonbar, from=Q2173043 Eocene mammals of Australia Eocene bats Prehistoric bat genera Prehistoric monotypic mammal genera Fossil taxa described in 1994

Taxonomy

Description

See also

References