ABSTRACT Skinks of the genus Sphenomorphus are one of the most speciose genera of lizards, with 115 presently recognised species. Their range extends across tropical Asia, making them suitable for studying speciation and biogeographic patterns. At present, five species of Sphenomorphus are reported from India. Four are from Northeast India, and one is from peninsular India, specifically the southwestern parts of Kerala state. The disjunct distribution of these species, with four occurring in the Northeast and one peninsular species, sets up an interesting scenario to test whether dispersal or vicariance led to their contemporary distribution. To investigate the factors contributing to this distribution, we generated a multilocus phylogeny of Sphenomorphus across their range and performed divergence dating to explore possible explanations. Our results showed that the peninsular Indian endemic, Sphenomorphus dussumieri , shares a sister relationship with a clade primarily distributed in the Sunda region. Our divergence dating and biogeographic analyses suggest transoceanic dispersal of the ancestral stock of S. dussumieri from the Sunda shelf to peninsular India at a time when the global sea levels were relatively low.
Borah et al. (Sat,) studied this question.