Australian Fossil Mammal Site - Naracoorte, South Australia
Over 2000 kilometres separate the Naracoorte (South Australia) and Riversleigh (Queensland) sites, which form the World Heritage Australian Fossil Mammal Site. The site at Naracoorte, South Australia, covers 300 hectares and is located in flat country, punctuated by a series of stranded coastal dune ridges that run parallel to the present coastline.
Description of place
The cool caves at Naracoorte are in stark contrast to the semi-arid conditions at Riversleigh. The Naracoorte fossils document a distinctive fauna, and illustrate faunal change spanning several ice ages, highlighting the impacts of both climatic change and humankind on Australia's mammals from at least 350,000 years before the present.
Snapshots of Pleistocene life
Ongoing research at the Naracoorte Caves sites is expected to document a series of snapshots of Pleistocene life in south-east Australia, including details of climate and vegetation associated with the fauna. Recent geological research suggests that deposits of Pliocene and even Miocene age could be found at the site, thus providing closer links with the site at Riversleigh.
Specimens representing 99 vertebrate species have been discovered, ranging in size from very small frogs to buffalo-sized marsupials. These include exceptionally preserved examples of the Australian Ice Age megafauna, as well as a host of modern species such as the Tasmanian devil, thylacine and others. The Naracoorte fossils span the probable time of the arrival of humans in Australia, and this is valuable in analysing the complex relationships between humans and their environment.
The sites, each highly significant in its own right, are presented as a serial World Heritage nomination. Together they represent the key stages in the development of Australia's mammal fauna. While there are other important Australian fossil mammal sites, Riversleigh and Naracoorte are outstanding for the extreme diversity and the quality of preservation of their fossils. They also provide links through time that unify the biotas of the past with those of today in the Wet Tropics of Queensland, the Gondwana Rainforests of Australia, and Kakadu National Park World Heritage properties.
Australian Fossil Mammal Site - Riversleigh, Queensland
Over 2000 kilometres separate the Naracoorte and Riversleigh sites, which form the World Heritage Australian Fossil Mammal Site. Riversleigh covers an area of 10,000 hectares, is located in north-west Queensland, and confined to the watershed of the Gregory River.
Description of place
Riversleigh is one of the world's richest Oligo-Miocene mammal records, linking that period (15-25 million years ago) to the predominantly modern assemblages of the Pliocene and Pleistocene epochs. The site provides exceptional examples of middle to late tertiary mammal assemblages, in a continent whose mammalian evolutionary history has been the most isolated and most distinctive in the world.
The extensive fossil deposits at Riversleigh are encased in hard, rough limestone, which was formed in lime-rich freshwater pools. They span a record of mammal evolution of at least 20 million years in length, providing the first records for many distinctive groups of living mammals, such as marsupial moles and feather-tailed possums, as well as many other unique and now extinct Australian mammals such as 'marsupial lions'.
The variety of deposits at Riversleigh has led to an understanding of how the environment has changed over time from a rich rainforest community to semi-arid grassland, and how the animals that lived in it have changed too.
The discovery of the fossils at Riversleigh has profoundly altered the understanding of Australia's mid-Cainozoic vertebrate diversity. The remains of a 15 million-year-old monotreme have provided new information about this highly distinctive group of mammals, and several Tertiary thylacines have been identified. Placental mammals are represented by more than 35 bat species and the Riversleigh fossil bat record is the richest in the world.