Two new cave-dwelling harvestmen from Western Australia (Arachnida: Opiliones: Assamiidae and "Phalangodidae")

Abstract

Two new species of laniatorid harvestmen have been collected in the biologically significant caves of the Cape Range Peninsula, Western Australia. Dampetnls isolatus sp. novo (Assamiidae) has reduced eyes but is otherwise not especially adapted for a subterranean life; it has been collected in several Cape Range caves. Glennhuntia glennhunti gen. et sp. novo (Phalangodidae) is a minute, highly evolved troglobite known only from Camerons Cave. Both species are likely rainforest relics. Some notes are provided on the Australian fauna of the harvestman Infraorder Grassatores. Hunt (1991) noted that fewer than 200 species of the arachnid order Opiliones (harvestmen, phalangids) had been described from Australia, a number he estimated to be no more than 20% of the total fauna. Indeed, Hunt himself was the first and last productive resident harvestman specialist in Australia, who had personally described a substantial portion of those species. His untimely demise put an end to a succession of fine papers on the systematics of several Australian taxa, most notably the Triaenonychidae, Neopilionidae and Megalopsalididae. While taking notice of the richness of the Australian fauna of the laniatorid infraorder Grassatores, Hunt published little on them. Four families of the infraorder, Assamiidae, Podoctidae, Zalmoxidae and Phalangodidae have been recorded from Australia. Four zalmoxid species, all in the genus Zalmoxis Sorensen, are known from Queensland, New South Wales, and the Kimberley Plateau of northern Western Australia. Austribal­ onius Roewer, with a single named species, is the only podoctid genus. The Assamiidae of Australia are dealt with in the remarks below under the description of the new species, and likewise the phalangodids under the description of Glennhuntia glennhunti. Specimens are deposited in the Western Australian Museum (WAM), Perth, and I thank Mark Harvey for making them available to me for study. Comments from two anonymous reviewers materially improved the manuscript. Glenn Hunt (1944-1999), whom I knew only through correspondence, had produced a series of outstanding systematic papers on Australian opilionids, working on a fauna that was almost unknown (compared to its potential richness) at the time he began. He recognized the two species described below as new and determined the assamiid as a species of Dampetrus Karsch. I'm honoured to be able to dedicate this brief paper to his memory