Like most 'discovered' countries, Australia had already been discovered by its original inhabitants - the Aborigines. Small nomadic tribes with many languages and ideas roamed the vast plains.
Much of mythology is to do with the Dreamtime, a wonderful Golden Age in the remote past when Gods were real Gods and anything was possible.
Relying on memory and scratched images, Australian mythology is seemingly fragile, but in many instances in this very dry atmosphere it's amazingly durable. Many of the fragments were trampled on by European invasion, but fortunately there has always been a strong oral tradition, and the legends of the Outback may be making a Comeback.
You can see rock painting pictures which is represented this Gods below.