Both species have as a diagnostic character the absence of precloacal pores, and we suggest here their presumptive systematic relationships in Liolaemus. We analyzed ten species of Liolaemus, in order to perform a phylogenetic analysis based on external morphology, using mostly squamation and morphometric characters. The analysis was performed using PAUP, with the Maximum Parsimony criterion. In addition, through diaphanisation, we studied and described the osteology of the new species. We conclude that species lacking precloacal pores do not form a monophyletic group, and that constructing a phylogeny using only external morphology, at least for this group of reptiles, is insufficient to establish solid phyletic relationships. Other sort of characters should complement the morphological ones.