A New Endemic Lizard from Sierra Pie de Palo in Western Argentina

Abstract

Endemic herpetofaunal elements characterize the several extra-Andean or Pampean embossments extending along the Andean mountains of Argentina, from 27° to 32° south latitude. That endemism is in agreement with both the independent tectonic and geological history of the isolated Pampean mountains (Caminos, 1979), and the geographical and ecological barriers resulting from the paleoclimatic events of the late Pleistocene glaciation (Cei, 1980a). The Sierra Pie de Palo is a steep longitudinal Precambrian and Paleozoic relief, 60 km long and 30 km wide, from 31°05' to 31°40' south latitude. It rises about 30 km east of the easternmost precordilleran slopes, at San Juan, central Argentina (Fig. 1). A preliminary ecological and biogeographical study of that still unexplored extra-Andean embossment revealed its peculiar physiognomic features (Cei, 1980b). Three phytogeographical and faunal altitudinal zones were recognized. In the higher zone, from 2800 to 3200 m, up to the summit, the only reptile found was a moderate-sized iguanid lizard of the genus Liolaemus. It is closely related to the Andean-Patagonian bibroni group, but is distinct from all other known taxa in significant morphological characters. Specimens of the new species are in the Museo Zoologico, Florence, Italy (MZUF), the Museum of Natural History, University of Kansas (KU), the Instituto M. Lillo, Universidad Nacional de Tu- cuman, Argentina G*ML) and in J. M. Cei-Diag- nostic Collection (JMC-DC).