excavation was carried out using two 2 × 1 m grid system .
a chance discovery at a rock shelter in southern australia has revealed a human settlement dating back 49,000 years .
 
that means once humans first set foot on the australian coastline , it took a mere 1,000 years for them to expand out into its dry interior - further evidence of the ingenuity of what now stands as the oldest continuous civilisation on earth .
the shelter , about 550 kilometres north of adelaide , also contains humans arrived in the arid interior of the country around 49,000 years ago .
 
the site , which is a newly discovered cave in the flinders ranges , about 550 km north of adelaide , is known as the warratyi rock - shelter .
 
the first exploratory trench ( squares 4c and 4d ) was located on the southern side of the shelter to provide a cross - section through potential living areas from east to west ( taking in part of the back wall ) .