Phylogenetic relationships of Chilean leptodactylids: a molecular approach based on mitochondrial genes 12S and 16S

Abstract

Most Chilean amphibians belong to the subfamily Telmatobiinae (Anura, Leptodactylidae). Several phylogenetic studies of Leptodactylidae and Telmatobimae, based principally on morphological characters, have implicitly suggested closer relationships of some species of the Telmatobimae with members of other subfamilies of leptodactylids, including the leptodactyline genus Pleurodema which is present in Chile. Furthermore, a growing number of molecular studies suggest a non monophyletic status for Telmatobiinae, although none of these studies have investigated the phylogenetic relationships of this subfamily. We compared partial sequences of the ribosomal mitochondrial genes 12S and 16S to determine the phylogenetic relationships of Chilean leptodactylids and its position within the modern anurans (Neobatrachia). We included 22 species from nine of the 10 genera of tehuatobiines present in Chile (Alsodes, Atelognathus, Batrachyla, Caudiverbera, Eupsophus, Hylorina, Insuetophrynus, Telmatobufo and Telmatobius), two species of the genus Pleurodema, and one species of Rhinodermatidae, which is considered a leptodactylid derivative family by some authors. We also included 51 species representing most of the families that compose Neobatrachia. Phylogenetic reconstructions were performed using the methods of maximum parsimony, maximum likelihood and Bayesian inference. The topologies obtained in all the analyses indicate that Telmatobimae is a polyphyletic assemblage, composed by species belonging to Hyloidea (most of the genera) and species more related to Australasian taxa (the clade Caudiverbera + Telmatobufo, defined as the tribe Calyptocephalellini). These molecular data support groups based on other kinds of evidence (Caudiverbera + Telmatobufo, Alsodes + Eupsophits and Batrachyla + Hylorina) and raise new phylogenetic hypotheses for several genera of telmatobiines (Atelognathus with Batrachyla and Hylorina, Insuetophrynus + Rhinoderma). The phylogenetic relationships recovered in this study suggest a multiple origin for Chilean temperate forest frogs and reveal an unexpected level of taxonomic diversity and evolutionary divergence among Chilean leptodactylids.