A new species of Aspidura Wagler, 1830 (Squamata: Colubridae: Natricinae) from Sri Pada sanctuary (Peak Wilderness), Sri Lanka.

We describe a new species, Aspidura ravanai sp. nov., representing the eighth species of the genus known from Sri Lanka. The new species is readily distinguished from all other congeners by its colour pattern, scalation, and genetic distinctiveness. Our molecular results indicated that Aspidura began diversifying in the Miocene approximately 18 Ma, and A. ravanai sp. nov. diverged from its likely sister lineage A. trachyprocta at least 6.2 Ma. The species is currently known only from the type locality, on the western slopes of Sri Pada Peak in the central highlands of Sri Lanka.

Genus-level phylogeny of snakes reveals the origins of species richness in Sri Lanka.

Snake diversity in the island of Sri Lanka is extremely high, hosting at least 89 inland (i.e., non-marine) snake species, of which at least 49 are endemic. This includes the endemic genera Aspidura, Balanophis, Cercaspis, Haplocercus, and Pseudotyphlops, which are of uncertain phylogenetic affinity. We present phylogenetic evidence from nuclear and mitochondrial loci showing the relationships of 40 snake species from Sri Lanka (22 endemics) to the remaining global snake fauna. To determine the phylogenetic placement of these species, we create a molecular dataset containing 10 genes for all global snake genera, while also sampling all available species for genera with endemic species occurring in Sri Lanka. Our sampling comprises five mitochondrial genes (12S, 16S, cyt-b, ND2, and ND4) and five nuclear genes (BDNF, c-mos, NT3 RAG-1, and RAG-2), for a total of up to 9582bp per taxon. We find that the five endemic genera represent portions of four independent colonizations of Sri Lanka, with Cercaspis nested within Colubrinae, Balanophis in Natricinae, Pseudotyphlops in Uropeltidae, and that Aspidura+Haplocercus represents a distinct, ancient lineage within Natricinae. We synonymize two endemic genera that render other genera paraphyletic (Haplocercus with Aspidura, and Cercaspis with Lycodon), and discover that further endemic radiations may be present on the island, including a new taxon from the blindsnake family Typhlopidae, suggesting a large endemic radiation. Despite its small size relative to other islands such as New Guinea, Borneo, and Madagascar, Sri Lanka has one of the most phylogenetically diverse island snake faunas in the world, and more research is needed to characterize the island's biodiversity, with numerous undescribed species in multiple lineages.