Systematics and biogeography of a Sunda-Papuan snake lineage (Natricidae: Tropidonophis Jan 1863)

Abstract Sunda-Papuan keelback snakes (Serpentes: Natricidae: Tropidonophis Jan 1863) include 20 species distributed from the Philippines south-east through the Moluccas to New Guinea and Australia. Diversity of this insular snake lineage peaks on the island of New Guinea. Previous phylogenetic studies incorporating Tropidonophis have been limited to multi-locus Sanger-sequenced datasets with broad squamate or family-level focus. We used a targeted-sequence capture approach to sequence thousands of nuclear ultraconserved elements (UCEs) to construct the most comprehensive sequence-based phylogenetic hypothesis for this genus and estimate ancestral biogeography. Phylogenies indicate the genus is monophyletic given recent taxonomic reassignment of Rhabdophis spilogaster to Tropidonophis. All UCE phylogenies recovered a monophyletic Tropidonophis with reciprocally monophyletic Philippine and New Guinean clades. Divergence dating and ancestral range estimation suggest dispersal to New Guinea from the Philippines to have occurred during the Mid-Miocene via the Oceanic Arc Terranes. From Late Miocene into the Pliocene the genus experienced rapid diversification from orogeny of the New Guinean Central Cordillera from Oceanic Arc Terrane accretion on the northern boundary of the Sahul Shelf. Future collecting of missing taxa from the Moluccas and Indonesian Papua will better the understanding of non-volant faunal biogeography and diversification in this tectonically complex Pacific arena.