Jorge Brito

Una especie nueva de rana arbórea del género Hyloscirtus (Amphibia: Anura: Hylidae) de la Cordillera del Cóndor

Ecuadorian frogs of genus Hyloscirtus comprises 16 described species, of which eleven belong to the H. larinopygion group. They are restricted to the flanks of the Andes, both east and west. An assessment of the herpetofauna in the southern part of Cordillera del Condor (montane forests on sandstone plateaus) province of Zamora Chinchipe, Ecuador, led to the discovery of a new species for the group, which we describe herein as Hyloscirtus condor sp. nov. We herein analyze the tadpoles and advertisement calls, as well as estimate the phylogenetic relationships of the new and related species, based on new sequences of mitochondrial genes 12S, tRNAValy 16S, until a total of 2508 bp. The results show that the group H. larinopygion comprises two clades: one occurring in the northern and central Andes, and the second in the south. The new species belongs to the southern clade, is sister to H. tapichalaca, and a seemingly undescribed species from Provincia Morona Santiago. The new species differs from all its congeners in color pattern, which consists of dark yellow dots on a tan background. It is the largest species of the H. larinopygion group and shares with H. tapichalaca the presence of a large prepollical curved spine and hypertrophied forearms. The new species inhabits a remote and well-preserved area of Cordillera del Condor. The discovery of new species and others at the site denotes the biological importance of this area and encourages the development of conservation plans.

A giant on the ground: another large-bodied Atractus (Serpentes: Dipsadinae) from Ecuadorian Andes, with comments on the dietary specializations of the goo-eaters snakes

Body-size is significantly correlated with the number of vertebrae (pleomerism) in multiple vertebrate lineages, indicating that somitogenesis process is an important factor dictating evolutionary change associated to phyletic allometry and, consequently, species fitness and diversification. However, the role of the evolution of extreme body sizes (dwarfism and gigantism) remains elusive in snakes, mainly with respect to postnatal ontogeny in dietary preferences associated with evolution of gigantism in many lineages. We described herein a new species in the highly diversified and species-rich genus Atractus on the basis of four specimens from the southeastern slopes of the Ecuadorian Andes. The new species is morphologically similar and apparently closely related to two other allopatric giant congeners (A. gigas and A. touzeti), from which it can be distinguished by their distinct dorsal and ventral coloration, the number of supralabial and infralabial scales, the number of maxillary teeth, and relative width of the head. In addition, we discuss on the ontogenetic trajectories hypotheses and dietary specializations related to evolution of gigantism in the goo-eaters genus Atractus.