The Bramble Cay melomys, or Bramble Cay mosaic-tailed rat ("Melomys rubicola"), is an extinct species of rodent in the family Muridae. While it was similar to the Cape York melomys it had some protein differences and a coarser tail. It was genetically different to species from Australia and New Guinea. It lived in burrows it had dug among plants, or under branches and leaves on the ground. It was a nocturnal animal, and scientists believe it was a vegetarian.