Sistemática e biogeografia do grupo Rhinella marina (Linnaeus, 1758) (Anura: Bufonidae)




This research aims the study of systematics and biogeography of the species in Rhinella marina group (Linnaeus, 1758). The present dissertation was structured in three chapters. The irst chapter presents the description of two new species, throughout central Brazil, and also focuses discussions about the taxonomy of the group. The second chapter investigated relationships (phylogeny) of the species in R. marina group using the total evidence (cutaneous secretions, molecular, and morphological characters), and cladistic methods (maximum parsimony and Bayesian analysis). An analysis of populational, individual, seasonal, and sexual variation proved that the cutaneous secretions characters seem not to have polymorphisms among the species studied. The characters provided a good number of information to resolve the relationships of the ingroup species, considered monophyletic. Discussions related to the contribution to phylogeny of each dataset (partition) were carried out. There is some incongruence among the characters sampled (cutaneous secretions, molecular, and morphological characters). Analyses of times of divergences using relaxed molecular clock, and fossils calibration indicate that the R. marina group is recent, and that its most recent ancestral originated about 8.5 million years, in Miocene irradiating until the Quaternary. A combination of factors involving geological, climatic, and physiological requirements could explain the present time species distribution (biogeographic scenario) in time and space. Ancestral analyses also indicate that the R. marina group originated in Brazilian central shield and, lately irradiated to other neotropic areas, mainly by dispersion.


sistematica biogeografia rainella fisiologia

Documentos Relacionados