The Sepik River (Papua New Guinea) is not a dispersal barrier for lowland rain-forest frogs

Two new species of green treefrogs (Pelodryadidae: Litoria) from the northern slopes of Papua New Guinea's Central Cordillera

We describe two new species of moderate-sized (male body length 26.5-29.8 mm and 41.0 mm), predominantly green treefrogs in the genus Litoria from hill forest on the northern slopes of Papua New Guinea's Central Cordillera. Phylogenetic analysis of mitochondrial ND4 nucleotide sequences shows that the first species is related to Litoria iris (Tyler) and its allies. It is morphologically most similar to Litoria mystax, a small green treefrog known only from the holotype that was described more than 100 years ago from the north coast of western New Guinea but differs from that species in having longer legs and a broader head. The second species is closest to Litoria gasconi, a species known only from the foothills of the Foja Mountains in Papua Province, Indonesian New Guinea, and the Prince Alexander Mountains in northern Papua New Guinea. It has a net average sequence divergence of 10% from L. gasconi and can be distinguished morphologically from it and from other pelodryadids by the presence of a striking pattern of spots and blotches on the ventral surfaces and on the hidden surfaces of the limbs. These descriptions add to the rapidly increasing known diversity of frogs in hill and lower montane forest, habitats that support the most diverse frog communities on mainland New Guinea.

Multiple trans-Torres Strait colonisations by tree frogs in the Litoria caerulea group, with the description of a new species from New Guinea

Australia and New Guinea (together referred to as Sahul) were linked by land for much of the late Tertiary and share many biotic elements. However, New Guinea is dominated by rainforest, and northern Australia by savannah. Resolving patterns of biotic interchange between these two regions is critical to understanding the expansion and contraction of both habitat types. The green tree frog (Litoria caerulea) has a vast range across northern and eastern Australia and New Guinea. An assessment of mitochondrial and morphological diversity in this nominal taxon in New Guinea reveals two taxa. True Litoria caerulea occurs in disjunct savannahs of the Trans-Fly, Central Province and across northern Australia, with very low genetic divergence, implying late Pleistocene connectivity. A previously unrecognised taxon is endemic to New Guinea and widespread in lowland swampy rainforest. Date estimates for the divergence of the new species suggest Pliocene connectivity across lowland tropical habitats of northern Australia and New Guinea. In contrast, the new species shows shallow phylogeographic structuring across the central mountains of New Guinea, implying recent dispersal between the northern and southern lowlands. These results emphasise that the extent and connectivity of lowland rainforest and savannah environments across northern Australia and southern New Guinea have undergone profound shifts since the late Pliocene. http://zoobank.org/urn:lsid:zoobank.org:pub:A577A415-0B71-4663-B4C1-7271B97298CD

Evidence for an intrinsic factor promoting landscape genetic divergence in Madagascan leaf-litter frogs

The endemic Malagasy frog radiations are an ideal model system to study patterns and processes of speciation in amphibians. Large-scale diversity patterns of these frogs, together with other endemic animal radiations, led to the postulation of new and the application of known hypotheses of species diversification causing diversity patterns in this biodiversity hotspot. Both extrinsic and intrinsic factors have been studied in a comparative framework, with extrinsic factors usually being related to the physical environment (landscape, climate, river catchments, mountain chains), and intrinsic factors being clade-specific traits or constraints (reproduction, ecology, morphology, physiology). Despite some general patterns emerging from such large-scale comparative analyses, it became clear that the mechanism of diversification in Madagascar may vary among clades, and may be a multifactorial process. In this contribution, I test for intrinsic factors promoting population-level divergence within a clade of terrestrial, diurnal leaf-litter frogs (genus Gephyromantis) that has previously been shown to diversify according to extrinsic factors. Landscape genetic analyses of the microendemic species Gephyromantis enki and its widely distributed, larger sister species Gephyromantis boulengeri over a rugged landscape in the Ranomafana area shows that genetic variance of the smaller species cannot be explained by landscape resistance alone. Both topographic and riverine barriers are found to be important in generating this divergence. This case study yields additional evidence for the probable importance of body size in lineage diversification.