The joint listing of two sites in two different areas of the country is a tribute to the outstanding representation of the evolution of
Australian mammals and the quality of their fossils. The
Riversleigh QLD fossil deposits are among the richest and most extensive in the world, with some fossils dating back to the Oligo-Miocene time, some 15-25 million years ago. The South Australian counterpart, the
Naracoorte Caves, are comparatively ‘young’: These cave shafts have acted as pitfall traps, collecting animals for at least 500,000 years. More than 100 fossil deposits have so far been found. Both
World Heritage Sites are in part accessible to visitors.