A phylogeny of the Trimeresurus group of pit vipers: New evidence from a mitochondrial gene tree

The Trimeresurus group is an important radiation of over 40 Asian pit viper species. Once considered congeneric, four genera are generally currently r ecognized (Trimeresurus sensu stricto, Ovophis, Protobothrops, and Tropidol aemus) but relationships within and between these are still unclear. This s tudy, based on mitochondrial cytochrome b sequences, is the first to includ e a large number of species (21) and demonstrates that the current taxonomy does not adequately represent either the relationships or the genetic dive rsity present in the complex. Although many deeper nodes are not strongly s upported, the following novel conclusions are all well supported: (1) the p araphyly of Trimeresurus sensu stricto, (2) the presence of several diverge nt clades within Trimeresurus sensu stricto, (3) the paraphyly of some wide spread, medically significant, species, (4) the nonmonophyly of Ovophis, an d (5) the monophyly of Protobothrops. Mapping of morphological characters o nto the mitochondrial tree further supports the four groups proposed for Tr imeresurus sensu stricto. (C) 2000 Academic Press.