Phylogenetic systematics of lizards of the genus Stenocercus (Squamata: Iguania) from the northern Andes

Abstract

The genus Stenocercus is composed of 61 species that occur mainly in the Andes and adjacent lowland areas (0-4 000 m) from northern Colombia and Venezuela to central Argentina. In this study, I performed parsimony and Bayesian analyses to infer the phylogenetic relationships among the 20 species of Stenocercus that occur in the northern Andes (Ecuador, Colombia, and Venezuela); I analyzed morphological, molecular, and combined datasets. These analyses resulted in similar topologies, which indicate that species of Stenocercus from the northern Andes are nested within 2 major clades. One of these clades contains 6 species occurring between southern Ecuador and southern Colombia, whereas the other clade includes 13 species that occur from southern Ecuador to northern Colombia and Venezuela. The results also suggest that the recent uplift of the northern Andes has had a major impact on the evolution of Stenocercus.