^yAMERICAN MUSEUM ISovitates PUBLISHED BY THE AMERICAN MUSEUM OF NATURAL HISTORY CENTRAL PARK WEST AT 79TH

A new Early Miocene iguanian lizard from New Mexico is described. This specimen is the oldest demonstrable member of the iguanine clade as determined by its possession of derived characters of Iguaninae as a whole and those of its two primary subclades. The phylogenetic relationships among iguanines are reevaluated with the inclusion of this and another recently described fossil iguanine. The fossil taxa increase the amount of phylogenetic resolution, and a single most parsimonious tree is found. The new fossil appears to be the sister group of Dipsosaurus and the clade formed by both taxa is the sister group of the remaining iguanines. Monophyly of the new taxon is poorly supported.