Riversleigh, in North West Queensland, is one of Australia's most renowned fossil sites. The 100 km² area contains fossil remains of ancient mammals, birds and reptiles of Oligocene and Miocene age. The site was inscribed as a World Heritage site in 1994 and is an extension of the Lawn Hill National Park. Fossils at Riversleigh are encased in limestone deposited by lime-rich freshwater pools, and in caves, at a time when the ecosystem was evolving from a rich rainforest to semi-arid gras… (More on Riversleigh)