Arnold's giant tortoise (Aldabrachelys gigantea arnoldi), also known as the Seychelles saddle-backed tortoise, is a tortoise subspecies of the Aldabra giant tortoise. It inhabited the large central granitic Seychelles islands, but was slaughtered in vast numbers by European sailors and settlers. By around 1840 it was presumed to be extinct, along with the Seychelles giant tortoise, a species which shared the same islands.