A new frog: Rhombophryne longicrus

Credit: Frank Glaw

Meet the long-legged diamond frog, Rhombophryne longicrus, the newest species to increase the count of Madagascan amphibians once again. Like the rest of the diamond frogs, it is small and brown, but it is also very different.

Characterised by its unusually long slender legs, that are also the reason for its name, the new species is unable to burrow its way through the ground like most of its relatives do. However, it makes up for that with longer leaps.

Found in Sorata, a massif in northern Madagascar, which is yet to be put under protection, the long-legged diamond frog is thought by its discoverers to be a microendemic. If this is the case, this new species could turn out to be at great risk due to the ongoing deforestation and forest degradation in the area. 

For our experts: The Madagascar-endemic microhylid genus Rhombophryne consists of a range of partly or completely fossorial frog species. They lead a poorly known, secretive lifestyle, and may be more diverse than previously thought. We describe a new species from the high altitude forests of the Sorata massif in north Madagascar with unusual characteristics for this genus; R. longicrus sp. n. has long, slender legs, unlike most of its fossorial or semi-fossorial congeners. The new species is closely related to R. minuta, a much smaller frog from the Marojejy massif to the southeast of Sorata with similarly long legs. We discuss the morphology of these species relative to the rest of the genus, and argue that it suggests adaptation away from burrowing and toward a more saltatorial locomotion and an accordingly more terrestrial lifestyle. If this is the case, then these frogs represent yet more ecological diversity within the already diverse Cophylinae. We recommend an IUCN Red List status of Endangered B1ab(iii) for R. longicrus sp. n., because it is known only from a single site in a forested area of roughly 250 km2, which is not yet incorporated into any protected area.