Abstract

A new species of lizard, belonging to the montanus group of the genus Liolaemus, is described from the northern Chile. The specimens of the new species were collected in February, 1999 at the Farellones de Tara, Loa Province, Antofagasta Region. Within the montanus group, the new species differs from the boulengeri group in lacking a patch of enlarged scales on the posterior thigh. It differs from the remaining species of the montanus group in having a high number of small, smooth, rounded dorsal body scale and differentiated head scales. From those species with similar pattern of squamation, the new species can be differentiated by its moderate size, tail shorter than snout - vent length, and distinctive color pattern. It has psammophilus habits and it occurs over 4,000 m of elevation. 1,775 bp of the mitochondrial genes ND1, ND2 and COI were amplified and sequenced from the holotype, allotype and one paratype. These were compared with ten species of Liolaemus, four of the chiliensis groups and six of the montanus group. Additionally, we used a specimen of Phymaturus as "outgroup". Sequences were aligned and analyzed with the programs Clustal W, Mc Clade, PAUP and MEGA2. The number of phylogenetically informative variable sites was 453. The genetic divergence of the new species from congeneric species of the chiliensis group was from 0.1780 to 0.1985 K2P units, whereas among the species of the montanus group it was from 0.0676 to 0.0857 K2P units. With respect to the Maximun Parsimony analysis, the shortest tree found had 1682 steps and the Consistency Index was 0.68, with a topology basically similar to that obtained with Maximum Likelihood and Distance. The principal component analysis allowed the differentiation of the new species from other six species of the montanus group, principally by body measurements that explain more than 84% of the variance. Thus, evidence from molecular and morphological data support the recognition of a new species.