Amphibians form an important endemic taxon in the Western Ghats. However, both their taxonomic and ecological status remains unresolved. Such lacunae hamper studies on their ecology.This study is an attempt to develop laboratory tools in molecular systematics to assess the diversity of amphibians in the Western Ghats. The phylogenetic affinity, systematic position and the biogeographic significance of a recently described frog from the Western Ghats was resolved.

The DNA was isolated, amplified and sequenced for targeted regions in mitochondrial genome (12s and 16s rDNA) of the species. The sequences were edited and manually aligned with other global anuran sequences of interest found in the GENEBANK. Phylogenetic analysis was done using PHYLIP, MEGA 2.01 and PHYLOWIN softwares to obtain maximum likelihood, maximum parsimony, minimum evolution and neighbour joining trees. Phylogenetic tree topology with maximum consensus was used to draw inferences. The genera Micrixalus, Nasikabatrachus, Heleophryne, Hemisus and Sooglossus formed distinct ancient lineages of amphibians belonging to the Gondwanaland. The evolution of these taxa was dated between 140-200 mya. This predates earlier estimates on the evolution of endemic families in the Gondwanaland masses. Our observations on the skeletal morphology, reproductive biology and life history traits of Nasikabatrachus and Micrixalus also lend support to the molecular data. The Cretaceous-Tertiary (K-T) boundary at 80-120 mya is considered as a corner stone in the evolutionary biology where several vertebrate lineages radiated. Our data suggests that events much before the K-T boundary, about 200 mya led to endemism of amphibian lineages in the Gondwanaland. It is hypothesized that amphibian fauna was insularized due to sea level rise upto 200 m from the present in late Jurassic, 200 mya. The first order Haq-Vail sea level surge lasted over 150 mya. We infer that this reduced habitats, promoted stochastic extinctions and prolonged isolation resulting in the evolution of amphibian endemism in the Gondwana breakaway landmasses.

In recent years phylogenetic diversity, which is measured in terms of evolutionary history is increasingly being used to identify areas and taxa of conservation importance. There is evidence that in the Western Ghats, endemic lineages of amphibians that have an ancient evolutionary history continue to persist. The data available on the recently discovered subterranean species Nasikabatrachus, however suggests that dam projects endanger its habitat in the Western Ghats and their survival.