Riversleigh World Heritage Area

Riversleigh
UNESCO World Heritage Site
Location	Gregory, Queensland, Australia
Part of	Australian Fossil Mammal Sites (Riversleigh / Naracoorte)
Criteria	Natural: (viii), (ix)
Reference	698-001
Inscription	1994 (18th Session)
Area	10,029 ha (38.72 sq mi)
Coordinates	19°2′S 138°38′E / 19.033°S 138.633°E
	Location of Riversleigh World Heritage Area in Queensland Riversleigh World Heritage Area (Australia)

Riversleigh in north west Queensland, Australia, is one of the Australian Fossil Mammal Sites listed by UNESCO as a World Heritage Site. The other is the Naracoorte Caves National Park in South Australia.^[1] The Riversleigh site is part of the Boodjamulla National Park. The fossil site covers an area of about 100 km².

The fossils that have been found are the remains of ancient mammals, birds and reptiles of Oligocene and Miocene epochs.^[2] The site was listed as a World Heritage site in 1994. The fossils at Riversleigh are rare because they are found in soft freshwater limestone which has not been compressed.^[3] This means the animal remains retain their three dimensional shape.

Fossils

Fossils at Riversleigh are found in limestone by lime-rich freshwater pools, and in caves. They are from when the ecosystem was evolving from rich rainforest to semi-arid grassland. Thirty-five fossil bat species have been found at the site, which is the richest in the world. A skull, complete with all its teeth, of a 15 million-year-old monotreme, Obdurodon dicksoni, shows how this Australia group of animals evolved. Fossil ancestors of the extinct thylacine, Thylacinus cynocephalus, have also been found at Riversleigh. In 1993, Nimbadon skulls were found in newly discovered cave.^[4] Scientists think this prehistoric marsupial first appeared about 15 million years ago and died out about 12 million years ago, perhaps from the effects of climate change.^[5] Other fossils have shown how the koala has changed in response to Australia's change from rainforest to drier eucalypt forests.^[6]

Fossils found at Riversleigh

Mammals

Ekaltadeta, a carnivorous rat-kangaroo
Burramys, the Mountain Pygmy Possum
Nimbacinus, an ancestor of the Thylacine
Obdurodon, a giant platypus
Yarala, a tube-nosed bandicoot
Yalkaparidon, a strange marsupial
Wakaleo, a marsupial lion
Priscileo, a marsupial lion
Nimiokoala, an ancient koala^[6]
Nimbadon, a sheep-like marsupial^[4]

Birds

Pengana, a flexible-footed bird of prey
Menura tyawanoides, a prehistoric lyrebird
The first fossil record of the Orthonychidae (logrunner) family

Reptiles

Trilophosuchus, a tree-dwelling crocodile
Baru, the cleaver-headed crocodile
Yurlunggur,^[3] and Wonambi, extinct snakes (Madtsoiidae)

References

Archer, M. et al. 1991. Riversleigh: the Story of Australia's Inland Rainforests, (Sydney: Reed Books).

↑ UNESCO, "Australian Fossil Mammal Sites (Riversleigh / Naracoorte)"; retrieved 2012-4-21.
↑ Archer M; Hand, Suzanne J. & Godthelp H. [1991] 2000. Australia's lost world: Riversleigh, World Heritage Site. Reed, Sydney.
↑ ^3.0 ^3.1 Anna Salleh (16 February 2006). "Huge skulls clues to snake evolution". ABC Science. Australian Broadcasting Corporation. Retrieved 5 August 2010.
↑ ^4.0 ^4.1 "Cave yields marsupial fossil haul". BBC News. 19 July 2010. Retrieved 5 August 2010.
↑ Australian Geographic 20 July 2010.
↑ ^6.0 ^6.1 Ancient koalas by Dan Gaffney. 19 December 2009 PhysOrg.com