No abstract

. (2013). Systematics of spiny-backed treefrogs (Hylidae: Osteocephalus): an Amazonian puzzle. -Zoologica Scripta, 42, 351-380. Spiny-backed tree frogs of the genus Osteocephalus are conspicuous components of the tropical wet forests of the Amazon and the Guiana Shield. Here, we revise the phylogenetic relationships of Osteocephalus and its sister group Tepuihyla, using up to 6134 bp of DNA sequences of nine mitochondrial and one nuclear gene for 338 specimens from eight countries and 218 localities, representing 89% of the 28 currently recognized nominal species. Our phylogenetic analyses reveal (i) the paraphyly of Osteocephalus with respect to Tepuihyla, (ii) the placement of 'Hyla' warreni as sister to Tepuihyla, (iii) the non-monophyly of several currently recognized species within Osteocephalus and (iv) the presence of low (<1%) and overlapping genetic distances among phenotypically well-characterized nominal species (e.g. O. taurinus and O. oophagus) for the 16S gene fragment used in amphibian DNA barcoding. We propose a new taxonomy, securing the monophyly of Osteocephalus and Tepuihyla by rearranging and redefining the content of both genera and also erect a new genus for the sister group of Osteocephalus. The colouration of newly metamorphosed individuals is proposed as a morphological synapomorphy for Osteocephalus. We recognize and define five monophyletic species groups within Osteocephalus, synonymize three species of Osteocephalus (O. germani, O. phasmatus and O. vilmae) and three species of Tepuihyla (T. celsae, T. galani and T. talbergae) and reallocate three species (Hyla helenae to Osteocephalus, O. exophthalmus to Tepuihyla and O. pearsoni to Dryaderces gen. n.). Furthermore, we flag nine putative new species (an increase to 138% of the current diversity). We conclude that species numbers are largely underestimated, with most hidden diversity centred on widespread and polymorphic nominal species. The evolutionary origin of breeding strategies within Osteocephalus is discussed in the light of this new phylogenetic hypothesis, and a novel type of amplexus (gular amplexus) is described. Corresponding author: Karl-Heinz Jungfer, Institute of Integrated Sciences, Department of Biology, University of Koblenz-Landau, Universit€ atsstr. 1, 56070 Koblenz, Germany. E-mail: khjungfer@aol.com Juli an Faivovich, Divisi on Herpetolog ıa, Museo Argentino de Ciencias Naturales 'Bernardino Rivadavia'-CONICET, Angel Gallardo 470, C1405DJR, Buenos Aires, Argentina and Departamento de Biodiversidad y Biologia Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina. E-mail: julian@macn.gov.ar Jos e M. Padial, Section of Amphibians and Reptiles, Carnegie Museum of Natural History, 4400 Forbes Avenue, Pittsburgh, PA, 15213-4080 Systematics of spiny-backed treefrogs K.-H. Jungfer et al. IntroductionTreefrogs of the genus Osteocephalus constitute an important component of the amphibian fauna of the Amazonian and Guianan regions of South America. Their distributions...

AimMapping Amazonian biodiversity accurately is a major challenge for integrated conservation strategies and to study its origins. However, species boundaries and their respective distribution are notoriously inaccurate in this region. Here, we generated a georeferenced database of short mtDNA sequences from Amazonian frogs, revised the species richness and the delimitation of bioregions of the Eastern Guiana Shield and estimated endemism within these bioregions. LocationAmazonia, with a focus on the Eastern Guiana Shield. Taxon studiedAmphibia: Anura. MethodsWe used an extensive DNA-based sampling of anuran amphibians of Amazonia using nextgeneration sequencing to delimit Operational Taxonomic Units (OTU) and their distribution. We analysed this database to infer bioregions using Latent Dirichlet Allocation modelling. We then compared endemism within these bioregions based on our results and the current IUCN database, and inferred environmental variables that contributed the most to the biogeographic pattern. ResultsThe recognized anuran species richness within the focal area increased from 440 species currently listed by the IUCN Red List to as much as 876 OTUs with our dataset. We recovered eight bioregions, among which three lie within the Eastern Guiana Shield. We estimated that up to 82% of the OTUs found in this area are endemic, a figure three times higher than the previous estimate (28%). Environmental features related to seasonal precipitations are identified as playing an important role in shaping Amazonian amphibian bioregions. Main conclusionsOur results have major implications for defining future conservation priorities of this vast area given that endemism in most Amazonian bioregions is vastly underestimated, and might therefore hide a large portion of threatened species. Moreover, these findings raise concern about meta-analyses based on public databases within Amazonia dealing with poorly known groups.

Species distributed across vast continental areas and across major biomes provide unique model systems for studies of biotic diversification, yet also constitute daunting financial, logistic and political challenges for data collection across such regions. The tree frog Dendropsophus minutus (Anura: Hylidae) is a nominal species, continentally distributed in South America, that may represent a complex of multiple species, each with a more limited distribution. To understand the spatial pattern of molecular diversity throughout the range of this species complex, we obtained DNA sequence data from two mitochondrial genes, cytochrome oxidase I (COI) and the 16S rhibosomal gene (16S) for 407 samples of D. minutus and closely related species distributed across eleven countries, effectively comprising the entire range of the group. We performed phylogenetic and spatially explicit phylogeographic analyses to assess the genetic structure of lineages and infer ancestral areas. We found 43 statistically supported, deep mitochondrial lineages, several of which may represent currently unrecognized distinct species. One major clade, containing 25 divergent lineages, includes samples from the type locality of D. minutus. We defined that clade as the D. minutus complex. The remaining lineages together with the D. minutus complex constitute the D. minutus species group. Historical analyses support an Amazonian origin for the D. minutus species group with a subsequent dispersal to eastern Brazil where the D. minutus complex originated. According to our dataset, a total of eight mtDNA lineages have ranges >100,000 km2. One of them occupies an area of almost one million km2 encompassing multiple biomes. Our results, at a spatial scale and resolution unprecedented for a Neotropical vertebrate, confirm that widespread amphibian species occur in lowland South America, yet at the same time a large proportion of cryptic diversity still remains to be discovered.

Anthropogenic habitat alteration has long been neglected as a factor in the analysis of predictability patterns in biological communities. We tested this factor by investigating anuran leaf litter assemblages in primary and secondary forests of Taï National Park, Ivory Coast, during two years.We measured predictability of assemblage composition by analyzing correlations between the off-diagonal elements of distance matrices based on (1) species distribution, (2) environmental characteristics, and (3) geographic distance. Pairwise correlations between matrices were significant in all cases when considering data pooled across time and habitats. A different pattern emerged when data were split according to season and disturbance level (i.e., primary vs. secondary habitats). Assemblage composition in primary habitats was correlated with geographic proximity of sites exclusively, indicating otherwise stochastic recruitment from a regional species pool at the local community level. In contrast, assemblage composition in secondary habitats was predictable based on environmental parameters, not geographical proximity. This can be inferred to be the result of a strong local site filter effect (i.e., physiologically more-restrictive conditions within secondary forest habitats, especially due to an altered microclimate). Results were consistent throughout seasons. The observed transition in predictability patterns indicates that anthropogenic disturbance not only affects system descriptors, such as species richness, abundance, and diversity, but may also alter the system's dynamics.