are the grass species of Eriachne and the sedges Cyperus cuspidatus and species of Fimbristylis, which occur in soils above the flood levels. The change in season has the species seek shelter during the day in sandstone formations and forage at local billabongs for a fern species Marsilea crenata. The high percentage of silica in its diet, 15 to 25% in some foliage, was proposed to have favoured the continual regeneration of molars. Attempts to locate the high silica fern in later surveys have not recorded Marsilea crenata at any sites, and the complex relationship between diet and dentition remains to be examined. Distribution and habitat The nabarlek is found in three distinct and geographically remote populations, one in Arnhem Land which includes Groote Eylandt, a larger island in the Gulf of Carpentaria, and another population between the Mary and Victoria Rivers at the Top End of the continent. The population in the northwest Kimberley region is confined to the coastal areas and on some of the islands in the Bonaparte Archipelago, these are Borda, Long, Hidden and Augustus Islands. The habitat is usually scrubby vegetation over sandstone formations, granitic outcrops, breakaways of laterite, boulder piles and rocky slopes. Conservation It is classified as Endangered by the IUCN. References External links Threatened Species of the Northern Territory Macropods Mammals of Western Australia Mammals of the Northern Territory Marsupials of Australia Mammals described in 1842