Amphibia, Anura, Leiuperidae, Pleurodema thaul: latitudinal and altitudinal distribution extension in Chile

The vast latitudinal extension of the Chilean territory determinates a climatic gradient which affects the distribution and diversity of its flora and fauna. From north to south, an increase of precipitation levels produces a gradual change from a desert climate (the Atacama Desert) to a temperate environment with oceanic influence in the austral extreme. Within this climatic gradient, the largest number of amphibian species, 66 % out of 56, is concentrated in central and southern Chile, between 38o and 46o S (Veloso and Navarro 1988; Ortiz and Diaz-Páez 2006). At the north of Chile, the majority of species is found in the Altiplanic zone (northeast limit of the country, 17o to 22o S) and belongs to genus Telmatobius (Formas et al. 2005). The situation is different in the coastal and interior zones of Northern Chile, where only two species have been recorded 29o S northward: Bufo atacamensis and Pleurodema thaul. Here, the Atacama Desert constitutes a natural barrier for the distribution of amphibians. On the other hand, the Andes Mountains also constitute an effective barrier for amphibian colonization on the east side of Chile.