 Australian forests are mostly made up of evergreen species , particularly eucalyptus trees in the less arid regions ; wattles replace them as the dominant species in drier regions and deserts . Among well @-@ known Australian animals are the monotremes ( the platypus and echidna ) ; a host of marsupials , including the kangaroo , koala , and wombat , and birds such as the emu and the kookaburra . Australia is home to many dangerous animals including some of the most venomous snakes in the world . The dingo was introduced by Austronesian people who traded with Indigenous Australians around 3000 BCE . Many animal and plant species became extinct soon after first human settlement , including the Australian megafauna ; others have disappeared since European settlement , among them the thylacine . 
