Three new species of torrent treefrogs (Anura, Hylidae) of the Hyloscirtus bogotensis group from the eastern Andean slopes and the biogeographic history of the genus

Abstract

The Hyloscirtus bogotensis group contains 17 species of treefrogs from the tropical Andes and Central America. A taxonomic review of the Amazonian clades of this group is presented based on DNA sequences of nuclear and mitochondrial DNA and a preliminary phylogenomic analysis of ultraconserved elements, as well as morphological, bioacoustic, and environmental characters. Additionally, the role of the Andes in the diversification of the genus Hyloscirtus is explored by reconstructing their ancestral basin (Amazon, Pacific, Caribbean). Our integrative analysis indicates the existence of eight undescribed candidate species within the group. Three of those species are described, previously masked within H. albopunctulatus, H. phyllognathus, and H. torrenticola. A lectotype is also designated for Hyla albopunctulata. The new evidence suggests that neither Hyloscirtus phyllognathus nor H. torrenticola occur in Ecuador. The new species, H. elbakyanae sp. nov., H. dispersus sp. nov., and Hyloscirtus maycu sp. nov. differ from other members of the group in bioacoustics and external morphology. The most useful diagnostic characters among species were advertisement calls. In contrast, skin coloration is highly variable intraspecifically and, as a result, of low diagnostic value. High variation in color is partly a result of phenotypic plasticity. Our biogeographic reconstructions indicate that the Andean barrier influenced the diversification of Hyloscirtus. Since the early Oligocene, there have been only four colonization events across de Andes, between the Pacific and Amazon basins. Two of those events occurred more than 14 Mya, when most of the tropical Andes were below 3000 m. Species in the highland H. larinopygion group are younger, suggesting recent diversification as high montane forests and paramo habitats emerged.