Two New Species of Pseudoeurycea (Caudata: Plethodontidae) from the Mountains of Northern Oaxaca, Mexico
Pseudoeurycea, with 34 described species, is one of the most diversified groups of neotropical salamanders. I generated a phylogenetic hypothesis of relationships for Pseudoeurycea and related taxa, based on DNA sequences of 16S, Cyt b, and ND4 mitochondrial genes. The analyses include 27 species of Pseudoeurycea and samples from the monotypic Lineatriton, Ixalotriton, and Parvimolge. All phylogenetic analyses resulted in a paraphyletic Pseudoeurycea. Ixalotriton and Pseudoeurycea parva always form a monophyletic group. P. parva is transferred to Ixalotriton based on morphological and molecular grounds. The phylogenetic position of the newly defined Ixalotriton clade is uncertain since it is part of an unresolved basal polytomy. Parvimolge is closely related to Pseudoeurycea, and it is also part of the basal polytomy. Lineatriton, a highly specialized taxon, is deeply nested within Pseudoeurycea. In order to provide a taxonomic arrangement consistent with the monophyly of the different units that reflects both evolutionary history and morphological specialization, Pseudoeurycea should be split into several taxonomic units.