Leaping towards a saltatorial lifestyle? An unusually long-legged new species of Rhombophryne (Anura, Microhylidae) from the Sorata massif in northern Madagascar

Mark D Scherz,Frank Glaw,Andolalao Rakotoarison,Oliver Hawlitschek,Miguel Vences

doi:10.3897/zse.91.4979

Abstract

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.

Highlights

The microhylid frog genus Rhombophryne (Anura, Microhylidae, Cophylinae) is receiving renewed taxonomic attention in the wake of recent genetic barcoding efforts on the frogs of Madagascar
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 long legs

Summary

Introduction

The microhylid frog genus Rhombophryne (Anura, Microhylidae, Cophylinae) is receiving renewed taxonomic attention in the wake of recent genetic barcoding efforts on the frogs of Madagascar. These DNA barcode studies revealed that less than 60% of the island’s amphibian diversity might so far have been formally described (Vieites et al 2009, Perl et al 2014). Still more have been discovered by additional fieldwork Five of these have been described recently (D’Cruze et al 2010, Glaw et al 2010, Scherz et al 2014, 2015), facilitated and accelerated by integrative approaches. These approaches are the key to closing the taxonomic gap in Madagascar’s amphibians, which is in turn key to understanding and protecting them

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