A revised phylogeny of macropathine cave crickets (Orthoptera: Rhaphidophoridae) uncovers a paraphyletic Australian fauna

Australian cave crickets are members of the subfamily Macropathinae (Orthoptera: Rhaphidophoridae). Thesubfamily is thought to have originated prior to the tectonic separation of the supercontinent Gondwana basedon distributions of extant lineages and molecular phylogenetic evidence, although the Australian fauna havebeen underrepresented in previous studies. The current study augments existing multigene data (using 12S, 16S,and 28S rRNA genes) to investigate the placement of the Australian representatives within the Macropathinaeand to assess divergence dates of select clades. Results suggest that the endemic Tasmanian genus Parvotettix isthe sister lineage to the remaining members of the subfamily, an outcome that presents a paraphyletic Australianfauna in contrast to previous studies. All other Australian taxa represented in this study (Micropathus andNovotettix) emerged as a sister group to the New Zealand and South American macropathine lineages. Estimationof phylogenetic divergence ages among the aforementioned clades were calibrated using two methods, in ab-sence of suitable fossil records: (i) tectonic events depicting the fragmentation of Gondwanan landmasses thatinvoke vicariant scenarios of present day geographic distributions; and (ii) molecular evolutionary rates.Geological calibrations place the median age of the most recent common ancestor of extant macropathines at∼125 to ∼165 Ma, whereas analyses derived from molecular substitution rates suggest a considerably youngerorigin of ∼32 Ma. This phylogenetic study represents the most rigorous taxonomic sampling of the Australiancave cricket fauna to date and stresses the influence of lineage representation on biogeographic inference.