The endangered southern cassowary and rare spotted-tailed quoll are some of the many threatened species, while the musky rat-kangaroo is one of 50 animal species that are unique to this area. The musky rat-kangaroo is significant because it represents an early stage in the evolution of kangaroos. Other rare animals include the yellow-bellied gliders and brush-tailed bettong. 107 mammal species have been identified. Australia's rarest mammal, the insectivorous Flores tube-nosed bat ("Murina florium"), is also found here. One quarter of Australia's rodent species are found within the Wet Tropics.