Phylogeny and conservation status of the Indian egg-eater snake, Elachistodon westermanni Reinhardt, 1863 (Serpentes, Colubridae): Supplementary material

The Indian egg-eater (Elachistodon westermanni) is a monotypic species of the Genus Elachistodon distributed across the Indian sub-continent. In Africa, there are 13 species of egg-eating snakes of the Genus Dasypeltis. These two genera, Elachistodon and Dasypeltis were thought to be closely related due to similar diet specialization, and shared biogeographic history between the Indian sub-continent and the continent of Africa. In our study, we amplified three mitochondrial genes and one nuclear gene from E. westermanni and reconstructed molecular phylogeny utilizing published sequences to understand the evolutionary relationships between the African, and the Indian egg-eating snakes. We used morphological characters to reinforce our inferences on phylogenetic relationships. We show that the Indian egg-eater is sister to a set of cat snakes of the Genus Boiga, and it does not share recent ancestry with the African egg-eating snakes. Morphological character states point at similarities between Elachistodon and Dasypeltis only in characters associated with their feeding behaviour. Elachistodon westermanni was similar to the Boiga spp. in several other morphological characters, and we provisionally assign E. westermanni under the genus Boiga. Compilation of records of E. westermanni across the Indian sub-continent over the years revealed a positive "Lazarus" effect. We conclude that, the egg-eating behaviour and the associated morphological characters in the snake genera Dasypeltis and Elachistodon are a result of convergent evolution. Based on the conservation status of E. westermanni, it could serve as a flagship species to conserve important wildlife habitats that are being lost rapidly in India.