Archipelago colonization by ecologically dissimilar amphibians: evaluating the expectation of common evolutionary history of geographical diffusion in co-distributed rainforest tree frogs in islands of Southeast Asia

Description of a new Kurixalus species (Rhacophoridae, Anura) and a northwards range extension of the genus

Knowledge of biodiversity before species become extinct is paramount to conservation, especially when the relevant species are far from their expected distribution and, thus, likely overlooked. Here, we describe a new Kurixalus species corresponding to a range extension of Kurixalus on the Asian mainland, with the closest population in Taiwan. The species diverged from its closest relative during the Late Pliocene to Pleistocene, ca. 3.06 Mya (HPD 95%: 5.82-0.01), based on calibrations with a relaxed clock species tree of unlinked mtDNA 12S rRNA and nuclear DNA TYR. The status of the newly-described species is also supported by a divergence in call properties and morphometrics. We named the species described here as Kurixalusinexpectatus sp. nov. due to the nature of the discovery, as well as the adjunct distribution of the species relative to its closest congeners. The species was found in Zhejiang Province and it represents a range extension of 663 km for the Kurixalus genus.

Geographical range evolution of the genus Polypedates (Anura: Rhacophoridae) from the Oligocene to present

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 Polypedatesfrom 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. leucomystaxstrongly 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.

From mainland to islands: colonization history in the tree frog Kurixalus (Anura: Rhacophoridae)

The origin and colonization history of Kurixalus, a genus of small arboreal tree frogs breeding exclusively in shallow swamps, is under disputed. On the basis of comprehensive sampling program, the evolutionary history of Kurixalus is investigated based on 3 mitochondrial genes. Our results indicate that the genus Kurixalus originated in the Asian mainland and subsequently arrived at its current distribution in Borneo, Taiwan, Ryukyu, and Hainan islands by a series of dispersal events. Moreover, the colonization of Taiwan from mainland Asia has occurred 2 times. The initial colonization of Taiwan occurred at 3.46–8.68 Mya (95% highest posterior density), which rejects the hypothesis that Kurixalus probably originated from Taiwan during the early Oligocene and favors the model of Neogene-origin rather than the model of Quaternary-origin for Taiwanese Kurixalus. Kurixalus eiffingeri has dispersed from Taiwan to the Ryukyus once or 2 times pending more data. Both transoceanic dispersal and landbridge dispersal have played a role in the colonization process; the former resulted in the colonization of Taiwan and the Ryukyus and the latter led to the colonization of Borneo and Hainan.

A new species of Kurixalus from western Yunnan, China (Anura, Rhacophoridae)

A new species of the genus Kurixalus (Anura: Rhacophoridae) is described from western Yunnan, China. Genetically the new species, Kurixalusyangisp. n., is closer to Kurixalusnaso than to other known congeners. Morphologically the new species is distinguished from all other known congeners by a combination of the following characters: smaller ratios of head, snout, limbs, IND, and UEW to body size; male body size larger than 30 mm; curved canthus rostralis; weak nuptial pad; brown dorsal color; absence of large dark spots on surface of upper-middle abdomen; presence of vomerine teeth; gold brown iris; single internal vocal sac; serrated dermal fringes along outer edge of limbs; granular throat and chest; rudimentary web between fingers; and presence of supernumerary tubercles and outer metacarpal tubercle.

The amphibians and reptiles of Mindanao Island, southern Philippines, II: the herpetofauna of northeast Mindanao and adjacent islands

We summarize all available amphibian and reptile species distribution data from the northeast Mindanao faunal region, including small islands associated with this subcenter of endemic vertebrate biodiversity. Together with all publicly available historical information from biodiversity repositories, we present new data from several major herpetological surveys, including recently conducted inventories on four major mountains of northeast Mindanao, and adjacent islands of Camiguin Sur, Dinagat, and Siargao. We present species accounts for all taxa, comment on unresolved taxonomic problems, and provide revisions to outdated IUCN conservation status assessments in cases where our new data significantly alter earlier classification status summaries. Together, our comprehensive analysis of this fauna suggests that the greater Mindanao faunal region possesses distinct subcenters of amphibian and reptile species diversity, and that until this area is revisited and its fauna and actually studied, with on-the-ground field work including targeted surveys of species distributions coupled to the study their natural history, our understanding of the diversity and conservation status of southern Philippine herpetological fauna will remain incomplete. Nevertheless, the northeast Mindanao geographical area (Caraga Region) appears to have the highest herpetological species diversity (at least 126 species) of any comparably-sized Philippine faunal subregion.

Macroevolution of hyperdiverse flightless beetles reflects the complex geological history of the Sunda Arc

The Sunda Arc forms an almost continuous chain of islands and thus a potential dispersal corridor between mainland Southeast Asia and Melanesia. However, the Sunda Islands have rather different geological histories, which might have had an important impact on actual dispersal routes and community assembly. Here, we reveal the biogeographical history of hyperdiverse and flightless Trigonopterus weevils. Different approaches to ancestral area reconstruction suggest a complex east to west range expansion. Out of New Guinea, Trigonopterus repeatedly reached the Moluccas and Sulawesi transgressing Lydekker's Line. Sulawesi repeatedly acted as colonization hub for different segments of the Sunda Arc. West Java, East Java and Bali are recognized as distinct biogeographic areas. The timing and diversification of species largely coincides with the geological chronology of island emergence. Colonization was not inhibited by traditional biogeographical boundaries such as Wallace's Line. Rather, colonization patterns support distance dependent dispersal and island age limiting dispersal.