Riversleigh, in North West Queensland, is Australia's most famous fossil site. The 100 km² area has fossil remains of ancient mammals, birds and reptiles of Oligocene and Miocene age.[1] The site was inscribed as a World Heritage site in 1994 and is an extension of the Boodjamulla National Park. The fossils at Riversleigh are rare because they are found in soft freshwater limestone which hasn't been compressed.[2] This means the animal remains retain their three dimensional structure.
[edit] Fossils
Fossils at Riversleigh are found in limestone by lime-rich freshwater pools, and in caves, when the ecosystem was evolving from rich rainforest to semi-arid grassland community. Thirty-five fossil bat species have been identified at the site, which is the richest in the world. The skull and nearly complete dentition of a fifteen million-year-old monotreme, Obdurodon dicksoni, provide a window into the evolution of this characteristically Australian group. Fossil ancestors of the recently extinct Thylacinus cynocephalus, the marsupial Tasmanian tiger, have also been identified among Riversleigh's fauna. In 1993, Nimbadon skulls were unearthed in a previously unknown cave in the region.[3] Researchers estimate that the prehistoric marsupial first appeared about 15 million years ago and died out about 12 million years ago, perhaps from climate change induced losses in habitat.[4] Other fossils have provided evidence of how the koala has evolved in response to Australia's change from predominate rainforest vegetation to dryer eucalypt forests.[5]
[edit] Creatures
- Mammals
- Marsupials
- Birds
- Reptiles
[edit] See also
[edit] References
- Archer, M. et al. 1991. Riversleigh: the Story of Australia's Inland Rainforests, (Sydney: Reed Books).
[edit] External links
|
|
|
| New South Wales |
|
|
| Northern Territory |
|
|
| Queensland |
|
|
| South Australia |
|
|
| Tasmania |
|
|
| Victoria |
|
|
| Western Australia |
|
|
| External territories |
|
|
|
|
|
Coordinates: 19°04′59″S 138°43′01″E / 19.083°S 138.717°E / -19.083; 138.717
