The Australian genus Theprisa Moore, 1963, is taxonomically revised to comprise five species, two newly described: Theprisadarlingtoni Liebherr & Porch, sp. nov. of Tasmania, and Theprisaotway Liebherr, Porch & Maddison, sp. nov. from the Otway Ranges, Victoria. Two previously described species, T.australis (Castelnau) and T.montana (Castelnau), are distributed in the mountains of Victoria. The third previously described species, T.convexa (Sloane) is found in Tasmania. A lectotype is designated for T.convexa because the various syntypes are ambiguously labelled. Cladistic analysis based on morphological characters establishes monophyly of Theprisa relative to the Australian genera Sitaphe Moore and Spherita Liebherr. This and a second clade of Australian genera (Pterogmus Sloane, Thayerella Baehr, and Neonomius Moore) do not form a natural group, but are cladistically interdigitated among two monophyletic New Zealand lineages (Tarastethus Sharp, and Trichopsida Larochelle and Larivière) suggesting substantial trans-Tasman diversification among these groups. Hypothesized relationships within Theprisa are consistent with two bouts of speciation involving the Bass Strait; an initial event establishing T.convexa as adelphotaxon to the other four species, and a more recent event establishing the sister species T.darlingtoni and T.montana. Geographic restriction of T.otway to the Otway Ranges is paralleled by Otway endemics in several other carabid beetle genera, as well as by endemics in numerous other terrestrial arthropod taxa. Whereas these numerous Otway endemics support the distinctive nature of the Otway Range fauna, their biogeographic relationships are extremely varied, illustrating that the Otways have accrued their distinctive biodiversity via various means.
Keywords: Allopatric speciation; area of endemism; biogeography; generic monophyly; phylogeny.
James K. Liebherr, Nick Porch, Matthew Shaw, Bronte E. Sinclair, David R. Maddison.