Systematics and Biogeography of Austral Rove Beetles (Staphylinidae: Euaesthetinae and Staphylininae)

Southern hemisphere rove beetles (Coleoptera: Staphylinidae) are poorly known taxonomically, and comprise many phylogenetically isolated taxa. This thesis presents fundamental systematic work on groups within the subfamilies Staphylininae (genus Creophilus) and Euaesthetinae. In Chapter II, the genus Creophilus is revised and two new species are described. A phylogenetic analysis of morphological characters of this and related genera revealed that genital, chaetotaxic and structural characters each contribute phylogenetic signal, with genital characters producing signal largely congruent with that of external structures. The monophyly of the austral C. erythrocephalus species-group was strongly supported. In Chapter III, a first broadly sampled phylogenetic analysis of subfamily Euaesthetinae did not recover the austral endemic genera as a monophyletic group, but did recover several genera and generic groupings as monophyletic. This chapter presented the first comprehensive morphological dataset for Euaesthetinae, reviewed the austral endemic genera, described larvae for many of them, and provided identification keys to both adults and larvae. In Chapter IV, the New Zealand euaesthetine genus Agnosthaetus is revised; 28 new species are described and taxonomic, ecological, and distribution data are synthesized for all known species. The genus is distributed throughout New Zealand, and its distribution patterns and phylogeny are the subject of Chapter V. This chapter presents a phylogenetic hypothesis for Agnosthaetus, in which two major lineages are recovered. These seem to be distributed mostly to the west or east, respectively, of the Alpine Fault – a geological structure representing the boundary between the Australian and Pacific tectonic plates. A biogeographic analysis revealed substantial biogeographic signal associated with the Alpine fault, and suggests an ancestral area for the genus in southern New Zealand. This area coincides with an area that probably survived the Oligocene Drowning Event, a period of maximum marine transgression in the Late Oligocene, ~28-33 million years ago. It is argued that invertebrate taxa such as Agnosthaetus are more likely than others to have maintained a continuous presence in New Zealand since it broke away from Gondwana, and will probably show biogeographic patterns matching both older and younger geological and paleogeographic processes.