Search for: All records

Identifying hotspots of biological diversity is a key step in conservation prioritisation. Melanesia—centred on the vast island of New Guinea—is increasingly recognised for its exceptionally species-rich and endemic biota. Here we show that Melanesia has the world’s most diverse insular amphibian fauna, with over 7% of recognised global frog species in less than 0.7% of the world’s land area, and over 97% of species endemic. We further estimate that nearly 200 additional candidate species have been discovered but remain unnamed, pointing to a total fauna in excess of 700 species. Nearly 60% of the Melanesian frog fauna is in a lineage of direct-developing microhylids characterised by smaller distributions than co-occurring frog families, suggesting lineage-specific high beta diversity is a key driver of Melanesian anuran megadiversity. A comprehensive conservation status assessment further highlights geographic concentrations of recently described range-restricted threatened taxa that warrant urgent conservation actions. Nonetheless, by world standards, the Melanesian frog fauna is relatively intact, with 6% of assessed species listed as threatened and no documented extinctions; and thus it provides an unparalleled opportunity to understand and conserve a megadiverse and relatively intact insular biota.

 

We describe a new species of Cornufer, subgenus Batrachylodes, from high-elevation forests of New Britain Island in the Bismarck Archipelago of Eastern Melanesia. The new species, Cornufer exedrus sp. nov., is a biogeographically disjunct member of the Batrachylodes clade, representing the first record of the subgenus from outside of the Solomon Archipelago. The new species is a small terrestrial form from dense, closed-canopy forests above 1500 meters elevation in the Nakanai Mountains of eastern New Britain. It differs from its closest relatives, the other members of the subgenus Batrachylodes, on the basis of its minute body size, degree of digital disc expansion, reduced subdigital tuberculation, color pattern, and other traits related to its small size. We also provide a description of the new species’ simple advertisement call. The diversity of ceratobatrachid frogs of the Bismarck Archipelago is most likely still underestimated despite several recent surveys. Our understanding of evolutionary trends and species boundaries in the subgenus Batrachylodes currently is hampered by lack of genetic samples and call recordings corresponding to voucher specimens of the endemic species of Bougainville Island.