Two underground craters measuring 400km together in size have been discovered in central Australia , sparking the possibility of a previously unknown asteroid impact event 300 million years ago that caused many species to go extinct . The impact zone was found in the Warburton Basin in two parts , each 200km wide , indicating the meteor that created them split into two before smashing into the earth . Even though it was found two kilometres underground , the impact zone is now the largest in the world , by over 100km . Dr Andrew Glikson from ANU indicates that the size of the asteroid means it could have impacted a mass extinction . The precise age of the crater is not yet known exactly , but researchers think it may be around 300 million years . ‘ We can not define this impact zone in anywhere near the degree of detail we can define the ones exposed on the surface , ' Lead Researcher Dr Andrew Glikson of the Australian National University told Daily Mail Australia . Researchers strongly believe the meteor could have caused the end of many life species on the planet at the time , including the dinosaurs . 'From the size - yes , it could have impacted a mass extinction , ' Dr Glikson said . 'Even though we do not know the exact age of the meteor yet , we do know life was very primitive at that time . ' The impact zone extends through the Earth 's crust which is around 30km thick in Central Australia . The two adjoining craters were thought to have been caused when a meteor split on its approach to Earth , forming two smaller ones each about 10km across . This impact zone , if confirmed , would be the largest in the world . The second largest is the Vredefort crater in South Australia , spanning 300km . This zone survives on the surface of Earth and therefore is easier to find than those underground . The impact zone was flagged after rock affected by heat and pressure was turned into glass . The impact zone was flagged after rock affected by heat and pressure , consequently being turned into glass was discovered , also known as shock metamorphism . The features of this metamorphism show that material was dramatically thrown out of the area in a span of more than 200km , indicating the possibility of a mass extinction . After using geothermal research to look at the internal heat of the earth and seismic data to see the vibrations of the earth 's surface , the team of geophysicists released high velocity shocks two kilometres underground by drilling . The impact zone was found in the Warburton basin in Central Australia and spans 400 kilometres . Scientists have been using information from a major 2010 discovery that showed a large meteorite strike 66 million years ago wiped out the dinosaurs . A plume of ash was sent up into the air from the impact and sediment from this collision is found in rocks around the world today . However , none of this sediment has been discovered in 300 million-year-old samples indicating that this site could be older . Further studies of the geochemistry and composition of the impact site are in progress .
Two kilometers each 10 kilometers across left a 400 kilometer impact zone in Australia . A team of scientists found the crater 400 kilometers underground . scientists say the impact could have caused mass animal extinctions . The zone was found with high velocity shocks and drilling into the earth . The impact may have happened around 300 million years ago .