Prehistoric AustralasiaFor most of the past 300 million years, the world's continents were interlinked as the supercontinents Pangaea and then Gondwana. Around 50 million years ago, Australia tore itself free from Antarctica to become the huge, splendidly isolated island it is today. Over time, its creatures began to evolve in ways not seen anywhere else on Earth, with tree climbing crocodiles, gigantic venomous lizards, walking omnivorous bats and flesh eating kangaroos