Crotaline Intergeneric Relationships Based on Mitochondrial DNA Sequence Data

We investigated phylogenetic relationships among 30 species of pit vipers representing all proposed genera except monotypic Ophryacus by comparing DNA sequence data from mitochondrial ND4 genes. Phylogenetic analysis was performed on two conserved subsets of the data. Retrieved topologies are discordant between these analyses, but it is difficult to make a compelling case for the superiority of one or the other data set for phylogenetic inference. Results common to both analyses, which we believe most likely reflect historical reality, include diphyly of Agkistrodon (s.l.); monophyly of (Hypnale + Calloselasma}; polyphyly of Agkistrodontini; monophyly of Protobothrops and of Trimeresurus (s.s.); paraphyly of bothropoid genera; and monophyly of American crotalines. The last suggests an Old World origin of Crotalinae with a single invasion of the New World.