Phylogenetics of the lizard genus Tropidurus (Squamata: Tropiduridae: Tropidurinae): direct optimization, descriptive efficiency, and sensitivity analysis of congruence between molecular data and morphology.

By use of the technique of direct optimization the phylogenetics of the cis-Andean lizard genus Tropidurus were examined on the basis of both molecular (ca. 1.04 kb of sequences from 12S rDNA, valine tDNA, and 16S rDNA) and morphological (93 characters) data. Although equal weighting of all parsimony cost functions logically must maximize descriptive efficiency and explanatory power of all evidence, a sensitivity analysis demonstrated that equal weighting of indels, transitions, transversions, and morphological change provided the most congruent solution between the molecular and the morphological data partitions. The position of Uranoscodon is resolved as the sister taxon of the remaining members of the Tropidurinae. Plica, Uracentron, and Strobilurus, previously considered synonyms of Tropidurus, are resurrected; the group of these three genera form the sister taxon of the former Tropidurus nanuzae group (herein named Eurolophosaurus) plus Tropidurus sensu stricto (composed of the T. bogerti, T. semitaeniatus, T. spinulosus, and T. torquatus groups, herein diagnosed).