Wikipedia
Riversleigh, in the north-west of Queensland, is Australia's most famous fossil site. The 100 km area has fossil remains of ancient mammals, birds and reptiles of Oligocene and Miocene age.
The fossils at Riversleigh are unusual because they are found in soft freshwater limestone which has not been compressed. This means the animal remains retain their three-dimensional structure. The area is located within the catchment of the Gregory River.
Fossils were first noted to exist in the area in 1901. An initial exploration survey was conducted in 1963. Since 1976 the area has been the subject of systemic exploration. 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.