Australia is unusual because the
animal population
evolved largely out of contact with the other main
continents. A very high percentage of Australian animals are endemic (found nowhere else) including about
70% of its
birds and
95% of its
mammals. Over time, the
marsupials filled most of the ecological niches that are normally occupied by
placental mammals. Australia is also home to the only three
monotreme species in the world - two
echidnas and the
platypus. The only placental mammals naturally found on the Australian mainland are
bats and some primitive
rodents; plus the
dingo, which came to
Australia somewhere around 7000 years ago.
Australia is also home to large and diverse populations of various other types of animal - snakes, lizards, insects, birds and fish.
Mammals
Monotremes
Marsupials
Placentals
Birds
Reptiles
Lizards
Snakes
Amphibians
Pest species
Recently extinct Australian fauna