Targeted surveys for two threatened, short-range endemic land snails in the southern MacDonnell Ranges, Northern Territory

The MacDonnell Ranges bioregion in the southern Northern Territory is a centre of land snail endemism in arid Australia, and a high proportion of species are listed as threatened under Northern Territory legislation. We sought to locate extant populations of two endemic and threatened land snails, each known only from a single location. We recorded the first live individuals of Tateropa aemula (Charopidae, Stylommatophora) at Penny Springs in Watarrka National Park since the type material was collected 131 years ago. We did not detect this species at other spring sites in this national park. We also located Divellomelon hillieri (Camaenidae, Stylommatophora) alive at one of two sites where it was previously recorded in Palm Valley, Finke Gorge National Park. The total area of occupancy at this site was ~0.6 hectares. Excluding wildfire from the habitat of both species through strategic fire breaks is a high priority, as well as removal of invasive buffel grass (Cenchrus ciliaris) at the D. hillieri site. We recommend that an updated conservation assessment is undertaken for T. aemula based on current knowledge of its distribution and threats. Further targeted survey should be undertaken for D. hillieri before undertaking a revised conservation assessment. We also report on other land snail species recorded during our surveys at both national parks.