Short-range endemic (SRE) invertebrates are animals that display restricted geographic distributions, nominally less than 10,000 km2, that may also be disjunct and highly localised. The most appropriate analogy is that of an island, where the movement of fauna is restricted by the surrounding marine waters, therefore isolating the fauna from other terrestrial populations. Isolating mechanisms and features such as roads, urban infrastructure, large creek lines and ridges can act to prevent the dispersal and gene flow of the less mobile invertebrate species. Subterranean fauna, which include stygofauna and troglofauna, typically comprise short-range endemics.