Riversleigh World Heritage Area

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Riversleigh
UNESCO World Heritage Site
Riversleigh.jpg
Location Gregory, Queensland, Australia
Part of Australian Fossil Mammal Sites (Riversleigh / Naracoorte)
Criteria Natural: (viii), (ix)
Reference 698-001
Inscription1994 (18th Session)
Area10,029 ha (38.72 sq mi)
Coordinates 19°2′S138°38′E / 19.033°S 138.633°E / -19.033; 138.633
Australia Queensland relief location map.jpg
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Location of Riversleigh World Heritage Area in Queensland
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Riversleigh World Heritage Area (Australia)

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. [1]

Contents

The fossils at Riversleigh are unusual because they are found in soft freshwater limestone which has not been compacted. [2] This means the animal remains retain their three-dimensional structure, rather than being partially crushed like in most fossil sites. The area is located within the catchment of the Gregory River. [3] Many of the fossil sites were crevices and limestone caves created by the action of large amounts of water on the karst formation, creating pitfall traps and feeding spots for predators which periodically and perhaps suddenly became covered and preserved; these conditions are responsible for the large assemblages of fossilised bats whose guano helped to conserve the remains of themselves and others.

Fossils were first noted to exist in the area in 1901. [4] An initial exploration survey was conducted in 1963. Since 1976, the area has been the subject of systemic exploration. [4] The site was co-listed with the Naracoorte Caves National Park in South Australia as a World Heritage Site in 1994, and by itself, it is an extension of the Boodjamulla National Park. [5]

Description

Nimbadon skeleton Composite Nimbadon lavarackorum skeleton from AL90, Riversleigh - journal.pone.0048213.g001.png
Nimbadon skeleton

Fossils at Riversleigh are found in limestone by lime-rich freshwater pools, and in caves, when the ecosystem was evolving from rich rainforest to semiarid grassland community. Some of the fossils at Riversleigh are 25 million years old. [6] High concentrations of calcium carbonate have meant the fossils are extremely well preserved. [6] The fossil collection reveals mammalian evolution across more than 20 million years. [3] Fossils have been found in more than 200 individual locations. [4] The fossil record here is significant because it provides evidence on evolution and the distribution of species across Gondwana.

The presence of Riversleigh fauna in the Oligo-Miocene has been classified by four "faunal zones", and used to denote the presence of fossil taxa in these time periods. [7] These may be summarised as

Thirty-five fossil bat species have been identified at the site, which is the richest in the world. [3] Cave deposits have been particularly rich in bat species. [4]

The skull and nearly complete dentition of a 15-million-year-old monotreme, Obdurodon dicksoni , provide a window into the evolution of this characteristically Australian group. Fossil ancestors of the recently extinct thylacine, Thylacinus cynocephalus, have also been identified among Riversleigh's fauna. In 1993, skulls of the koala-like Nimbadon were unearthed in a previously unknown cave in the region. [8] Researchers estimate that this marsupial first appeared about 15 million years ago and died out about 12 million years ago, perhaps from climate change-induced losses in habitat. [9] A well-preserved skull of the ancient Nimbacinus dicksoni , an extinct relative of the thylacine, has been used to determine the hunting behavior of the species. [10]

Other fossils have provided evidence of how the koala has evolved in response to Australia's change from predominant rainforest vegetation to drier eucalypt forests. [11] The fossil bird fauna at Riversleigh includes an artamid Kurrartapu johnnguyeni , a fossil sittella, [12] and representatives of various other families of modern birds. [13] [14] [15] Some fossil insects and plants have also been discovered. [4]

The fossil species identified at the sites are collectively known as the Riversleigh fauna. [16]

Research

Scientific studies are mostly conducted by a group of palaeontologists from the University of New South Wales. [6] Mike Archer is a paleontologist who has been working at Riversleigh since 1983. He and his co-workers discovered that diluted acetic acid was the most effective method of extracting fossils. [4] Karen Black, a palaeontologist from UNSW, discovered a new species of extinct koala, at Riversleigh, which was then named after Dick Smith. [17]

See also

Related Research Articles

<i>Obdurodon</i> Extinct genus of monotremes

Obdurodon is a genus of extinct platypus-like Australian monotreme which lived from the Late Oligocene to the Late Miocene. Three species have been described in the genus, the type species Obdurodon insignis, plus Obdurodon dicksoni and Obdurodon tharalkooschild. The species appeared much like their modern day relative the platypus, except adults retained their molar teeth, and unlike the platypus, which forages on the lakebed, they may have foraged in the water column or surface.

<span class="mw-page-title-main">Peramelemorphia</span> Order of mammals

The order Peramelemorphia includes the bandicoots and bilbies. All members of the order are endemic to 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.

<i>Wakaleo</i> Extinct genus of marsupials

Wakaleo is an extinct 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.

<i>Ekaltadeta</i> Extinct genus of marsupials

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.

<i>Nimbadon</i> Extinct genus of marsupials

Nimbadon is an extinct genus of marsupial, that lived from the Late Oligocene to the Miocene epoches. Many fossils have been found in the Riversleigh World Heritage property in north-western Queensland. It is thought to have an arboreal lifestyle.

<i>Litokoala</i> Extinct genus of marsupials

Litokoala is an extinct genus of marsupials, and along with Nimiokoala, is closely related to the modern koala. The three genera may have diverged at an earlier date, although the drying of the continent and the expansion of Eucalyptus forests towards the late Miocene may have delayed the evolution of cranial features unique to the modern genera. This indicates that either fossil genus could be an ancestor of the modern genus, or the modern genus has a common ancestor to both. More material needs collection to improve their taxonomical relationships.

Naraboryctes philcreaseri is a fossil species of marsupial found at early Miocene deposits of Boodjamulla National Park of Riversleigh area, northwestern Queensland, 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.

Eoanseranas handae, also sometimes referred to as Hand's dawn magpie goose, is an extinct genus and species of bird. Allied to the family Anseranatidae, which are represented by modern magpie geese, it existed during the Late Oligocene or Early Miocene of northern Australia. It was described from fossil material found at a Carl Creek Limestone site at Riversleigh, in the Boodjamulla National Park of northwestern Queensland. It was slightly smaller than its perceived descendant, the extant magpie goose Anseranas semipalmata.

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.

<i>Microleo</i> Extinct genus of marsupials

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.

Joculusium muizoni is a fossil species discovered at the Riversleigh World Heritage Area. Little is known about the animal.

Brevipalatus mcculloughi is a species of bat that existed in the early Miocene. It was discovered at a fossil deposit of the Riversleigh World Heritage Area.

Hipposideros winsburyorum is a hipposiderid species of bat known by fossil specimens, one of the many new taxa of chiropterans discovered in the Riversleigh World Heritage Area. The species existed during the Pliocene.

<i>Crash bandicoot <span style="font-style:normal;">(species)</span></i> Fossil species of marsupial

Crash bandicoot is an extinct bandicoot, known from fossils located at the Riversleigh World Heritage Area in northeast Australia.

Liyamayi dayi is a mammal species of the Thylacomyidae family known from fossils located at the Riversleigh World Heritage Area in northeast Australia. The discovery of the specimens was identified as deposited around fifteen million years ago, revising the earliest record of this peramelemorphian lineage from those of species that existed around ten million years later.

Karen H. Black, born about 1970, is a palaeontologist at the University of New South Wales. Black is the leading author on research describing new families, genera and species of fossil mammals. She is interested in understanding faunal change and community structure in order to gain new understandings of past, current and future changes in biodiversity which are driven by climate.

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.

Bettongia moyesi is a fossil species of potoroid marsupial.

References

  1. ↑ Archer M; Hand, Suzanne J. & Godthelp H. [1991] 2000. Australia's lost world: Riversleigh, World Heritage Site. Reed, Sydney.
  2. ↑ Anna Salleh (16 February 2006). "Huge skulls clues to snake evolution". ABC Science. Australian Broadcasting Corporation. Archived from the original on 11 November 2012. Retrieved 5 August 2010.
  3. 1 2 3 "Australian Fossil Mammal Site - Riversleigh more information". Department of Sustainability, Environment, Water, Population and Communities. 15 May 2008. Archived from the original on 21 September 2013. Retrieved 28 July 2012.
  4. 1 2 3 4 5 6 The Australian Heritage Council (2012). Australia' Fossil Heritage: A Catalogue of Important Australian Fossil Sites. Csiro Publishing. pp. 43–44. ISBN   978-0643102309. Archived from the original on 5 March 2024. Retrieved 28 July 2012.
  5. ↑ "Australian Fossil Mammal Sites (Riversleigh / Naracoorte)". UNESCO World Heritage Centre. Archived from the original on 10 May 2015. Retrieved 17 May 2015.
  6. 1 2 3 "Riversleigh World Heritage Site, Boodjamulla (Lawn Hill) National Park: Nature, culture and history". Department of Environment and Resource Management. 14 December 2011. Archived from the original on 13 September 2011. Retrieved 28 July 2012.
  7. ↑ "Faunal zones". Faunal encyclopedia. wakaleo.net. Archived from the original on 15 September 2017. Retrieved 28 May 2019.
  8. ↑ "Cave yields marsupial fossil haul". BBC News . 19 July 2010. Archived from the original on 8 August 2010. Retrieved 5 August 2010.
  9. ↑ Fossils reveal prehistoric life cycle [ permanent dead link ]. Australian Geographic. 20 July 2010.
  10. ↑ Jonathan Marker (10 April 2014). "This meat-eating marsupial may have hunted prey larger than itself". Science Recorder News. Archived from the original on 13 April 2014. Retrieved 11 April 2014.
  11. ↑ Dan Gaffney (19 December 2009). "Loud and lazy but didn't chew gum: Ancient koalas". PhysOrg . PhysOrg.com. Archived from the original on 30 June 2019. Retrieved 5 August 2010.
  12. ↑ Nguyen, JMT (2016). "Australo-Papuan treecreepers (Passeriformes: Climacteridae) and a new species of sittella (Neosittidae: Daphoenositta) from the Miocene of Australia". Palaeontologia Electronica. 19.1.1A: 1–13. doi: 10.26879/602 .
  13. ↑ Boles, WE (1998). "A budgerigar Melopsittacus undulatus from the Pliocene of Riversleigh, North-western Queensland". Emu . 98 (1): 32–35. doi:10.1071/MU98004.
  14. ↑ Boles, WE (2005). "A review of the Australian fossil storks of the genus Ciconia (Aves: Ciconiidae), with the description of a new species". Records of the Australian Museum . 57 (2): 165–178. doi: 10.3853/j.0067-1975.57.2005.1440 .
  15. ↑ Nguyen, JMT, Hand SJ, Archer M (2016). "The late Cenozoic passerine avifauna from Rackham's Roost Site, Riversleigh, Australia". Records of the Australian Museum . 68 (5): 201–230. doi: 10.3853/j.2201-4349.68.2016.1668 .
  16. ↑ "wakaleo.net — Riversleigh News and Faunal Encyclopedia". Archived from the original on 26 April 2017. Retrieved 12 January 2014.
  17. ↑ Queensl, The University of; Lucia, Australia Brisbane St; Gatton, QLD 4072 +61 7 3365 1111 Other Campuses: UQ; Maps, UQ Herston; Queensl, Directions © 2022 The University of. "20 million year old koala named after Dick Smith". UQ News. Archived from the original on 13 November 2022. Retrieved 15 April 2022.{{cite web}}: CS1 maint: numeric names: authors list (link)

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