Phylogenetic relationships of the species of neotropical horned frogs, genus Hemiphractus (Anura: Hylidae: Hemiphractinae), based on evidence from morphology

We reassess the phylogenetic relationships among the species of the neotropical genus Hemiphractus (Hylidae: Hemiphractinae), including a species only recently described. Parsimony analysis of 48 morphological and behavioral characters resulted in a single most parsimonious tree: ((H. helioi (H. scutatus, H. fasciatus)) (H. johnsoni (H. bubalus, H. proboscideus))). Loss of digital pads and other characters on the feet appear to be associated with terrestrial habits of several species. Our analysis supports a previous hypothesis concerning the sequence of events related to the evolution of casqued heads and co-ossification of cranial skin. The present distribution of the species partially corresponds to a previously proposed model of speciation of Andean frogs and may have been influenced by both geological events in the Andes and climatic events through the Quaternary.