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Currently, the genus Polypedates comprises 26 species distributed in South, Southeast, and East Asia. Because of their relatively low dispersal capability and intolerance to seawater, this genus is ideal for the study of terrestrial range evolution that extends into the island archipelagos of southeastern Asia. In this study, based on data compiled for Polypedates from previous studies and partial mitochondrial and nuclear genes collected in this study, we performed systematic biogeographical analysis. We confirmed a Sundaland origin for the extant genus and showed northward dispersal into mainland Southeast Asia and Asia, which coincided with the timing of paleoclimatic change from the Oligocene to Middle Miocene. Climate fluctuations had a profound impact on species diversification within the genus Polypedates. Furthermore, the Red River did not mediate species exchange between Southeast Asia and mainland Asia until the end of the Miocene, with the sudden onset of northward dispersal in several clades independently at that time. Alternatively, the lineage of widespread insular P. leucomystax strongly supports the hypothesis of terrestrial connection between island archipelagos of Southeast Asia during the Mid-Pleistocene paleoclimate fluctuations. Our biogeographical analysis also supports the recent introduction of P. leucomystax to the Philippines and Ryukyus, as previously suggested.
A new cypridopsine genus, Cyprettadopsis gen. nov., described here, is principally characterized by the reduced caudal ramus, the strongly serrated claw G2 of the antenna (A2), the A2 subquadrate terminal segment, the undivided penultimate segment of the second thoracopod (T2), the morphology of the third thoracopod bearing a distinctly separated terminal segment, the complete septa on the posteroventral margin and the incomplete septa on the anterior margin of both valves. Based on a combination of these characters, a new tribe, Cyprettadopsini trib. nov., is created in the subfamily Cypridopsinae Kaufmann, 1900 to accommodate this new genus, and one new species, Cyprettadopsis sutura gen. et sp. nov., is described as the type species. Apart from the above generic characters, the following features are also typical of the new species: the tiny needlepoint-like pores along the anterior and ventral margins of both valves, the remarkably large β-seta on the mandibular palp and the considerably short d2 seta on the T2. The presence of marginal septa in the new genus is a distinctive character and constitutes the first record of this feature within Cypridopsinae. The taxonomically relevant characters in the new taxon and related taxa are briefly discussed.
A new giant species of the subfamily Rhynchoproctinae with strikingly bi-coloured, red-yellow legs contrasting with a black body is described: Alienostreptus bicoloripes sp. nov. from Vietnam. The new species is assigned to the genus Alienostreptus Pimvichai, Enghoff & Panha, 2010 hitherto comprising one species, A. alienus (Attems, 1936), and differing from other rhynchoproctine genera by having the femoral spine duplicated. Species of this genus share three synapomorphic characters of the subfamily, viz (1) anterior coxal fold forms deep concavity in posterior view, (2) posterior coxal fold very low, and (3) posterior coxal fold with mesal flap. A superficially very similar colourful species from Borneo, also with bi-coloured legs but clearly not belonging to Alienostreptus due to the position of ventral soft pads on male legs, is documented based on photographs.