Continuous characters in a phylogenetic analysis of the frog genus Telmatobius (Anura, Ceratophrydae)

BARRIONUEVO, JOSÉ SEBASTIÁN

San Javier, Tucumán, Argentina

Congreso; XXVII Meeting of the Willi Hennig Society and VIII Reunión Argentina de Cladística y Biogeografía; 2008

Willi Hennig Society

Frogs of the genus Telmatobius are aquatic dwellers of Andean streams and lakes. Currently it comprises 57 species from Ecuador to Argentina. So far the proposed phylogenies of Telmatobius include only species restricted to Peru and failed to resolve the internal relationships. The lack of clear external characters has led to a generalized use of morphometrics in the taxonomic studies of the genus. As exposed by Hayek et al. (2001) amphibians are soft body organisms whose fixed body form is affected strongly by fixation making morphometric comparisons spurious. Additionally the lack of external structures, especially evident in Telmatobius, precludes the establishment of precise measure limits as can be established in other animal groups like reptiles, scorpions, and spiders. For these reasons I explore the performance of this type of characters in a phylogenetic analysis of Telmatobius. I generated a morphological matrix of 131 discrete characters of osteology (94), external morphology (24), larvae (9), chromosomes (2), and reproductive biology (2) for 23 species of the genus from Argentina, Bolivia and Peru and for 11 outgroup species. As in TNT is now possible to incorporated continuous characters in a phylogenetic analysis I incorporated 15 of those characters. I compare the topologies from the analysis based on discrete characters with the combined analysis (discrete and continuous characters). Also I compare the differences in group support between both analyses. There are important differences in topologies between both analyses as separate but the group supports of the combined analysis are improved. These results suggest that the continuous characters, as shown in other groups, are phylogenetically informative and the incorporation of these data strengths the phylogenetic hypotheses.