Dental morphology and diet in anuran amphibians from south India

The morphology of the jaw and palatine surfaces of eight species of metamorphosed anuran amphibians ( Microhyla ornata, M. rubra, Uperodon systoma, Tomopterna rolandae, Polypedates maculatus, Rana cyanophlycris, R. crassa and R. hexadactyla ) from a locality in south India, were examined by scanning electron microscopy. A relationship was observed between dentition (or its absence) and diet. In large prey feeders, there is a strong tendency towards the development of large secondary (or even tertiary) cusps, while myrmecophagous and termitophagous species lack teeth.
In the largely folivorous adults of Rana hexadactyla , secondary cusps are reduced to faint ridges and the tooth is cylindro-conical (as opposed to the recurved teeth with apices oriented lingually or distally in the insectivorous species). Although the phylogenetic relationships within members of the community are largely unknown, the oral armature is reflective of diet, and may represent adaptive suites.