g. Lötters 1996; Lötters et al. 2002). Moreover, the only harlequin frogs known to possess a middle ear are included in this group (absent in most members of the genus; Lötters 1996). However, not all species used in our phylogeny have been studied for ear ossicle conditions, so that phylogenetic information can only be expected here (Fig. 4). Within this Amazonian clade, two sub-clades are evident, supported by high bootstrap and Bayesian posterior probability values. One includes the species from central to southern Peru and Bolivia, i.e. an A. tricolor-clade (see Fig. 4). The other is comprised of all studied

species from the upper portion of the Amazon River plus the eastern Guiana Shield and the portion of the Amazon basin adjacent to it. Our data strongly support the eastern Guiana HDAC cancer Shield Atelopus forming a monophyletic subset of this clade. Similar to the results of Noonan and Gaucher (2005), Guianan Atelopus are little differentiated, as reflected by the weak support of groupings among them. Our findings fully support Noonan and Gaucher (2005) who suggested that DV predictions Selleck Wnt inhibitor are well applicable to harlequin frogs. Fig. 4 ML phylogram of different Atelopus species from all over the genus’ range (Table 1) based on the mitochondrial 16S rRNA gene

showing that Amazonian Atelopus constitute a monophyletic unit with those from the eastern Guiana Shield nested within them. Numbers above branches indicate Maximum Likelihood

bootstrap support/Bayesian posterior probabilities values. Species names are accompanied by GenBank accession numbers. This tree was rooted with Eleutherodactylus cf. johnstonei (not shown). It is also indicated in the Atelopus species if presence (*) or absence (**) of a middle ear is known Atelopus species from the Venezuelan Andes and the Caribbean coastal range, i.e. proximate to the Guiana Shield, show osteological and external morphological characters suggesting a closer relationship to Colombian Andean taxa (McDiarmid 1971). However, we lack other characters, such as those from molecular phylogenetics studies, to validate or dispose this view. Divergence in climate envelopes and allopatry Prediction accuracy of MaxEnt climate envelope models was high as suggested by ‘excellent’ AUC values Phosphoglycerate kinase (western Amazonian Atelopus: test 0.955, training 0.980; eastern Amazonian Atelopus: test 0.979, training 0.985) following the AUC classification accuracy of Swets (1988). Comparing box plots (Fig. 5), the available climate space as well as climate envelopes of western and eastern Amazonian Atelopus are similar as ranges of all bioclimatic parameters in our modelling approach largely overlap. Two of the temperature parameters, ‘annual mean temperature’ and ‘maximum temperature of the warmest month’, are rather alike (i.e.