Where in Australia are echidnas found?

The echidna found in New Guinea is a different species to that found in Australia. The theory goes that Australia, New Guinea, the islands of Oceania, South America, Africa and Antarctica were all once part of a supercontinent known as Gondwana. With continental drift, the continents and islands separated, this isolating certain animal types to selected parts of the world - this is one of the reasons why the majority of marsupials are found in Australia. Being close together, New Guinea and Australia would have been one of the last to separate. The long-beaked echidna of New Guinea would have adapted to the high terrain and humid conditions of the island, while the short-beaked echidna of Australia developed ina way that enabled it to live virtually anywhere on the flatter, drier, continent.