Riversleigh

Riversleigh is Australia's most famous fossil locality, a roughly 100 square kilometer area of fossiliferous limestone near the Gregory River in northwest Queensland, within the catchment of Boodjamulla National Park, recognized as part of the Australian Fossil Mammal Sites World Heritage property. Its fossils span the Late Oligocene through the Late Miocene, in four faunal zones ranging from about 28.4 to 5.3 million years ago, preserved in soft, uncompacted freshwater limestone that left many specimens three-dimensional rather than crushed, with many recovered from karst cave systems and limestone crevices that acted as pitfall traps. More than 290 species have been identified at the site, including the toothed platypus relative Obdurodon dicksoni, the koala-like marsupial Nimbadon, the thylacine relative Nimbacinus dicksoni, and an especially rich assemblage of bats.