The Bramble Cay Melomys ( Melomys rubicola) has one of the most unusual and precarious distributions of all Australian mammals. The melomys is restricted to an unstable 4-5 hectare coral.

The Bramble Cay melomys -- also known as the "mosaic-tailed rat" -- lived on a cay, a reef island made up of coral rubble and sand, located in the eastern Torres Strait. It was known as the.