Patterns of evolution in two South American species groups of the lizard family Gymnophthalmidae (Reptilia: Squamata)

The Gymnophthalmidae is a New World lizard family composed of approximately 30 genera distributed throughout Middle and South America. Taxonomy of the family has been dynamic, but only recently have the relationships of the genera been studied intensively. The Cercosaurini is one of two tribes within subfamily Cercosaurinae of the Gymnophthalmidae. In previous phylogenetic studies, two clades of genera consistently were identified as sister taxa within Cercosaurini. These genera were selected for the current analysis because there was evidence that the current taxonomy did not coincide with their evolutionary relationships. This study renders a classification in agreement with a proposed cladistic phylogeny and attempts to understand the processes in the evolution of these South American taxa.; A total of 515 museum specimens were examined for external morphological characters, which consisted of a combination of meristic, qualitative, and morphometric data. Phylogenetic analyses were performed using PAUP* to reconstruct the evolutionary relationships of the taxa. In addition to phylogenetic methods, multivariate statistics were utilized to examine species differences and GIS was used to visualize geographic ranges of the species.; The clade consisting of the genera Cercosaura, Pantodactylus, and Prionodactylus was investigated first. Each species and subspecies was examined to determine its taxonomic validity. The analysis concluded that neither Pantodactylus nor Prionodactylus was sufficiently distinct to warrant generic status. Both genera are considered junior synonyms of Cercosaura and a new definition and key to the species of Cercosaura is provided.; The genus Proctoporus consists of 27 recognized Andean species whose relationships and monophyly had never been assessed. A phylogenetic reconstruction of all species of Proctoporus was performed. Monophyly of this group was well supported and the intrageneric relationships were discussed. Finally, a biogeographic theory for the evolution of Proctoporus was presented.; In addition to the generic review of Proctoporus, a finer scale analysis of the P. bolivianus complex was performed using both morphological and molecular data. This complex occurs in southern Peru and Bolivia and was found to contain more diversity than was previously acknowledged. Two new species were described. It is likely that additional species exist, but confirmation must await further collection.