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The Neotropical region is the most diverse on the planet, largely owing to its mosaic of tropical rainforests. Multiple tectonic and climatic processes have been hypothesized to contribute to generating this diversity, including Andean orogeny, the closure of the Isthmus of Panama, the GAARlandia land bridge and historical connections among currently isolated forests. Micrathena spiders are diverse and widespread in the region, and thus a complete phylogeny of this genus allows the testing of hypotheses at multiple scales. We estimated a complete, dated phylogeny using morphological data for 117 Micrathena species and molecular data of up to five genes for a subset of 79 species. Employing eventc-based approaches and biogeographic stochastic mapping while considering phylogenetic uncertainty, we estimated ancestral distributions, the timing and direction of dispersal events and diversification rates among areas. The phylogeny is generally robust, with uncertainty in the position of some of the species lacking sequences. Micrathena started diversifying around 25 Ma. Andean cloud forests show the highest in-situ speciation, while the Amazon is the major dispersal source for adjacent areas. The Dry Diagonal generated few species and is a sink of diversity. Species exchange between Central and South America involved approximately 23 dispersal events and started ~20 Ma, which is consistent with a Miocene age for the Isthmus of Panama closure. We inferred four dispersal events from Central America to the Antilles in the last 20 Myr, indicating the spiders did not reach the islands through the GAARlandia land bridge. We identified important species exchange routes among the Amazon, Andean cloud forests and Atlantic forests during the Plio-Pleistocene. Sampling all species of the genus was fundamental to the conclusions above, especially in identifying the Andean forests as the area that generated the majority of species. This highlights the importance of complete taxonomic sampling in biogeographic studies.

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The Caatinga is a nucleus of seasonally dry tropical forest (SDTF) known as a hotspot of diversification and endemism. Despite its importance, this biome is still insufficiently sampled, resulting in extensive knowledge gaps regarding its species richness and composition. In this study we report two species of Xenoctenidae that are endemic to, and widely distributed in the Caatinga. We redescribe and illustrate Odo vittatus (Mello-Leito, 1936), the only xenoctenid species previously known from the Caatinga. We transfer this species to Xenoctenus Mello-Leito,1938, a genus currently known from six species restricted to Argentina, Bolivia, and Colombia. We also newly describe the male of Xenoctenus vittatus comb. nov. and provide new records of this species, which was hitherto known only from the type-locality, throughout the Caatinga and nearby semiarid vegetation formations. We also describe and illustrate a new species, Xenoctenus kaatinga sp. nov., based on males and female specimens collected throughout the Caatinga. Additionally, we propose diagnostic characters for Xenoctenus and redescribe the type-species, X. unguiculatus.

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The South American palpimanid genus Fernandezina Birabn currently comprises 15 described species, all known from epigean environments. Representatives of Fernandezina are easily recognized by the unexpanded femora I in both sexes and by the dorsally extended opisthosomal scutum in males. Herein, F. fernandoi sp. nov. is described based on males and females from hypogean environments and F. angeloi sp. nov. is described based on a single male from a nearby epigean environment, both in Brazil. Additionally, we provide an identification key for the species of the genus.

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The genus Runcinioides is revised, including the redescription of R. argenteus Mello-Leitão, 1929 and R. litteratus (Piza, 1933). The male of R. litteratus is described and illustrated for the first time and Misumenops paranensis (Mello-Leitão, 1932) is here considered a junior synonym of R. argenteus. The known geographic distribution of both species is expanded with the inclusion of new occurrence data. Runcinioides pustulatus Mello-Leitão, 1929 and Runcinioides souzai Soares, 1942 are not related to the other species of the genus, and provisionally considered as incertae sedis.

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Traditional conservation techniques for mapping highly biodiverse areas assume there to be satisfactory knowledge about the geographic distribution of biodiversity. There are, however, large gaps in biological sampling and hence knowledge shortfalls. This problem is even more pronounced in the tropics. Indeed, the use of only a few taxonomic groups or environmental surrogates for modelling biodiversity is not viable in mega-diverse countries, such as Brazil. To overcome these limitations, we developed a comprehensive spatial model that includes phylogenetic information and other several biodiversity dimensions aimed at mapping areas with high relevance for biodiversity conservation. Our model applies a genetic algorithm tool for identifying the smallest possible region within a unique biota that contains the most number of species and phylogenetic diversity, as well as the highest endemicity and phylogenetic endemism. The model successfully pinpoints small highly biodiverse areas alongside regions with knowledge shortfalls where further sampling should be conducted. Our results suggest that conservation strategies should consider several taxonomic groups, the multiple dimensions of biodiversity, and associated sampling uncertainties.

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Traditional conservation techniques for mapping highly biodiverse areas assume there to be satisfactory knowledge about the geographic distribution of biodiversity. There are, however, large gaps in biological sampling and hence knowledge shortfalls. This problem is even more pronounced in the tropics. Indeed, the use of only a few taxonomic groups or environmental surrogates for modelling biodiversity is not viable in mega-diverse countries, such as Brazil. To overcome these limitations, we developed a comprehensive spatial model that includes phylogenetic information and other several biodiversity dimensions aimed at mapping areas with high relevance for biodiversity conservation. Our model applies a genetic algorithm tool for identifying the smallest possible region within a unique biota that contains the most number of species and phylogenetic diversity, as well as the highest endemicity and phylogenetic endemism. The model successfully pinpoints small highly biodiverse areas alongside regions with knowledge shortfalls where further sampling should be conducted. Our results suggest that conservation strategies should consider several taxonomic groups, the multiple dimensions of biodiversity, and associated sampling uncertainties.

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The spider genus Mecynogea comprises nine species distributed predominantly in the Neotropics. Although the genus has been revised recently, several aspects of its taxonomy and morphology are still unresolved. In this paper, Mecynogea infelix (Soares Camargo, 1948) is removed from the synonymy of Mecynogea bigibba Simon, 1903 and redescribed. Mecynogea chavona Levi, 1997 is considered a junior synonym of M. infelix. The male of Mecynogea buique Levi, 1997 is described and illustrated for the first time. The internal female genitalia of M. buique and M. infelix is described and shown to be remarkably different from each other. We show that part of the intraspecific variation reported previously for the female of M. infelix is the result of epigynum mutilation, possibly during copulation. We also report the presence of an internal branch on the terminal apophysis in the male palp of Mecynogea species. This structure, in some species visible only on the expanded bulb, is shown to be present in all Cyrtophorinae. The internal branch of the terminal apophysis, together with the conductor fully fused to the tegulum, is herein proposed as synapomorphic for the subfamily. Mecynogea lemniscata (Walckenaer, 1841) is recorded for the first time in Bolivia. We also provide new Brazilian records for M. infelix, M. bigibba, M. buique, M. eryhtromela (Holmberg, 1876), and M. sucre Levi, 1997. Mecynogea carvalhoi Mello-Leitão, 1944, currently considered a nomen dubium, is revalidated, transferred to Argiope Audouin, 1826, redescribed and illustrated for the first time.

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A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

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Gnaphosidae Pocock are a very diverse spider family with remarkable spinning organ morphology. Although the family has received intense taxonomic attention in recent years, its intergeneric relationships remain obscure. A phylogenetic analysis of Gnaphosidae genera was performed to untangle the evolutionary history of the family. A matrix of 324 morphological characters, scored for 71 gnaphosid genera and 29 outgroup taxa, was analysed through parsimony and Bayesian phylogenetic inference. Gnaphosidae are not recovered as a monophyletic group, neither were most of the previously proposed intrafamiliar groupings. In accordance with the phylogenetic results obtained, Vectius Simon and Hemicloea Thorell are transferred to Trochanteriidae, and Xenoplectus Schiapelli & Gerschman de Pikelin to Liocranidae. Micaria Westring, Nauhea Forster and Verita Ramírez & Grismado (and some related genera) are probably not gnaphosids, although their phylogenetic placement is uncertain. Gnaphosidae s.s. are defined as spiders with enlarged piriform gland spigots, longer and wider than the major ampullate gland spigots. Within Gnaphosidae s.s., well-supported clades allow the redefinition, on the basis of quantitative phylogenetic evidence, of Gnaphosinae Pocock, Zelotinae Platnick, Herpyllinae Platnick, Drassodinae Simon, Prodidominae Simon rank res. and the newly proposed Leptodrassinae subfam. nov. Many genera are not assigned to subfamily given their poorly supported and unstable relationships. The homology and evolution of structures such as the claw tuft clasper, the spinning organs and the modification of cheliceral promargin are discussed.

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ABSTRACT A list of spider species is presented for the Belém Area of Endemism, the most threatened region in the Amazon Basin, comprising portions of eastern State of Pará and western State of Maranhão, Brazil. The data are based both on records from the taxonomic and biodiversity survey literature and on scientific collection databases. A total of 319 identified species were recorded, with 318 occurring in Pará and only 22 in Maranhão. About 80% of species are recorded at the vicinities of the city of Belém, indicating that sampling effort have been strongly biased. To identify potentially high-diversity areas, discounting the effect of variations in sampling effort, the residues of a linear regression between the number of records and number of species mapped in each 0.25°grid cells were analyzed. One grid, representing the Alto Turiaçu Indigenous land, had the highest deviation from the expected from the linear regression, indicating high expected species richness. Several other grid cells showed intermediate values of the regression residuals, indicating species richness moderately above to the expected from the model.

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A list of spider species is presented for the Belém Area of Endemism, the most threatened region in the Amazon Basin, comprising portions of eastern State of Pará and western State of Maranhão, Brazil. The data are based both on records from the taxonomic and biodiversity survey literature and on scientific collection databases. A total of 319 identified species were recorded, with 318 occurring in Pará and only 22 in Maranhão. About 80% of species are recorded at the vicinities of the city of Belém, indicating that sampling effort have been strongly biased. To identify potentially high-diversity areas, discounting the effect of variations in sampling effort, the residues of a linear regression between the number of records and number of species mapped in each 0.25°grid cells were analyzed. One grid, representing the Alto Turiaçu Indigenous land, had the highest deviation from the expected from the linear regression, indicating high expected species richness. Several other grid cells showed intermediate values of the regression residuals, indicating species richness moderately above to the expected from the model.

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Although Brazil is a megadiverse country and thus a conservation priority, no study has yet quantified conservation gaps in the Brazilian protected areas (PAs) using extensive empirical data. Here, we evaluate the degree of biodiversity protection and knowledge within all the Brazilian PAs through a gap analysis of vertebrate, arthropod and angiosperm occurrences and phylogenetic data. Our results show that the knowledge on biodiversity in most Brazilian PAs remain scant as 71% of PAs have less than 0.01 species records per km2. Almost 55% of Brazilian species and about 40% of evolutionary lineages are not found in PAs, while most species have less than 30% of their geographic distribution within PAs. Moreover, the current PA network fails to protect the majority of endemic species. Most importantly, these results are similar for all taxonomic groups analysed here. The methods and results of our countrywide assessment are suggested to help design further inventories in order to map and secure the key biodiversity of the Brazilian PAs. In addition, our study illustrates the most common biodiversity knowledge shortfalls in the tropics.

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Amazonian rivers are usually suggested as dispersal barriers, limiting biogeographic units. This is evident in a widely accepted Areas of Endemism (AoEs) hypothesis proposed for Amazonian birds. We empirically test this hypothesis based on quantitative analyses of species distribution. We compiled a database of bird species and subspecies distribution records, and used this dataset to identify AoEs through three different methods. Our results show that the currently accepted Amazonian AoEs are not consistent with areas identified, which were generally congruent among datasets and methods. Some Amazonian rivers represent limits of AoEs, but these areas are not congruent with those previously proposed. However, spatial variation in species composition is correlated with largest Amazonian rivers. Overall, the previously proposed Amazonian AoEs are not consistent with the evidence from bird distribution. However, the fact that major rivers coincide with breaks in species composition suggest they can act as dispersal barriers, though not necessarily for all bird taxa. This scenario indicates a more complex picture of the Amazonian bird distribution than previously imagined.

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The spider genus Oxyopes Latreille occurs throughout the world, but is insufficiently known in South America and the Caribbean. In this study, three apparently related species of this genus are reported from the region. Oxyopes salticus Hentz, 1845 is redescribed and illustrated, and extreme variation in colour pattern and in female genitalia is reported within this species. Oxyopes m-fasciatus Piza, 1938 and Oxyopes nigrolineatus Mello-Leitão, 1941 are both considered junior synonyms of O. salticus. The material examined in this study, together with information from the literature, show this species is widely distributed throughout the continental Americas and the Caribbean. Oxyopes crewi Bryant, 1948 is redescribed and illustrated, and its geographic distribution is extended to Bahamas, Cuba, Dominican Republic, Jamaica, and Saint Kitts. A new species, Oxyopes incantatus sp. nov., is described and illustrated for the first time based on specimens from the Galápagos Islands.

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Here we compile a list of spider species recorded in Mato Grosso do Sul state (Brazil), based on information from the taxonomic literature and unpublished inventories. The list includes 228 species in 134 genera and 32 families. Only approximately 35% of the state area have records of spider species, and no more than 5% of the area presents more than one record per 0.5° grid cell (2,916 km2). There are large gaps in the knowledge of the states spider fauna, particularly in the northern Pantanal. Most of the species are known by less than 10 distribution records, indicating that their geographic distribution is virtually unknown. Extrapolating a species accumulation curve, we show that a ten-time increase in sampled area would be necessary to discover 90% of the species occurring in the state. Number of species: in the world, 44,906; in Brazil, 3,730; in Mato Grosso do Sul, 228. Therefore new inventories are essential for an adequate description of the spider fauna of the state of Mato Grosso do Sul.(AU)

Nós compilamos uma lista de espécies de aranhas registradas no Mato Grosso do Sul (Brasil) a partir da literatura taxonômica e de inventários não publicados. A lista inclui 228 espécies em 134 gêneros e 32 famílias. Apenas cerca de 35% da área do estado apresenta registros de ocorrência de espécies de aranhas, e não mais que 5% apresenta mais de um registro de ocorrência por quadrícula de 0,5° (2.916 km2). Existem grandes lacunas de amostragem no estado, particularmente na porção norte do Pantanal. A maioria das espécies tem menos de 10 registros de ocorrência, ou seja, sua distribuição geográfica é praticamente desconhecida. Extrapolando a curva de acumulação de espécies dessas aranhas, concluímos que seria necessário ampliar em 10 vezes a área amostrada para que sejam listadas 90% das espécies que ocorrem no estado. Número de espécies: no mundo, 44.906; no Brasil, 3.730; no Mato Grosso do Sul, 228. Portanto, novos inventários são essenciais para que a araneofauna do Mato Grosso do Sul seja minimamente conhecida.(AU)

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ABSTRACT Here we compile a list of spider species recorded in Mato Grosso do Sul state (Brazil), based on information from the taxonomic literature and unpublished inventories. The list includes 228 species in 134 genera and 32 families. Only approximately 35% of the state area have records of spider species, and no more than 5% of the area presents more than one record per 0.5° grid cell (2,916 km2). There are large gaps in the knowledge of the states spider fauna, particularly in the northern Pantanal. Most of the species are known by less than 10 distribution records, indicating that their geographic distribution is virtually unknown. Extrapolating a species accumulation curve, we show that a ten-time increase in sampled area would be necessary to discover 90% of the species occurring in the state. Number of species: in the world, 44,906; in Brazil, 3,730; in Mato Grosso do Sul, 228. Therefore new inventories are essential for an adequate description of the spider fauna of the state of Mato Grosso do Sul.

RESUMO Nós compilamos uma lista de espécies de aranhas registradas no Mato Grosso do Sul (Brasil) a partir da literatura taxonômica e de inventários não publicados. A lista inclui 228 espécies em 134 gêneros e 32 famílias. Apenas cerca de 35% da área do estado apresenta registros de ocorrência de espécies de aranhas, e não mais que 5% apresenta mais de um registro de ocorrência por quadrícula de 0,5° (2.916 km2). Existem grandes lacunas de amostragem no estado, particularmente na porção norte do Pantanal. A maioria das espécies tem menos de 10 registros de ocorrência, ou seja, sua distribuição geográfica é praticamente desconhecida. Extrapolando a curva de acumulação de espécies dessas aranhas, concluímos que seria necessário ampliar em 10 vezes a área amostrada para que sejam listadas 90% das espécies que ocorrem no estado. Número de espécies: no mundo, 44.906; no Brasil, 3.730; no Mato Grosso do Sul, 228. Portanto, novos inventários são essenciais para que a araneofauna do Mato Grosso do Sul seja minimamente conhecida.

RESUMO

Here we compile a list of spider species recorded in Mato Grosso do Sul state (Brazil), based on information from the taxonomic literature and unpublished inventories. The list includes 228 species in 134 genera and 32 families. Only approximately 35% of the state area have records of spider species, and no more than 5% of the area presents more than one record per 0.5° grid cell (2,916 km2). There are large gaps in the knowledge of the states spider fauna, particularly in the northern Pantanal. Most of the species are known by less than 10 distribution records, indicating that their geographic distribution is virtually unknown. Extrapolating a species accumulation curve, we show that a ten-time increase in sampled area would be necessary to discover 90% of the species occurring in the state. Number of species: in the world, 44,906; in Brazil, 3,730; in Mato Grosso do Sul, 228. Therefore new inventories are essential for an adequate description of the spider fauna of the state of Mato Grosso do Sul.

Nós compilamos uma lista de espécies de aranhas registradas no Mato Grosso do Sul (Brasil) a partir da literatura taxonômica e de inventários não publicados. A lista inclui 228 espécies em 134 gêneros e 32 famílias. Apenas cerca de 35% da área do estado apresenta registros de ocorrência de espécies de aranhas, e não mais que 5% apresenta mais de um registro de ocorrência por quadrícula de 0,5° (2.916 km2). Existem grandes lacunas de amostragem no estado, particularmente na porção norte do Pantanal. A maioria das espécies tem menos de 10 registros de ocorrência, ou seja, sua distribuição geográfica é praticamente desconhecida. Extrapolando a curva de acumulação de espécies dessas aranhas, concluímos que seria necessário ampliar em 10 vezes a área amostrada para que sejam listadas 90% das espécies que ocorrem no estado. Número de espécies: no mundo, 44.906; no Brasil, 3.730; no Mato Grosso do Sul, 228. Portanto, novos inventários são essenciais para que a araneofauna do Mato Grosso do Sul seja minimamente conhecida.

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The American gnaphosid genus Apopyllus Platnick & Shadab is found from southern Mexico to southern Argentina. It can be diagnosed by the complex shape of the RTA, by the membranous tegular extension, the long coiled embolus, the retrolateral incision on the cymbium, the long convoluted copulatory duct extending anteriorly to the copulatory openings and by the presence of paramedian epigynal pockets and of an anterior ridge on the epigynum. The RTA characters are important in species taxonomy but the complex shape and variation of the RTA hampers identification, especially regarding the two most common species: A. suavis (Simon) and A. silvestrii (Simon). In this paper the genus is revised, the genital morphology is described, and homology between its components and those of other genera is discussed. Apopyllus suavis is considered a senior synonym of Apopyllus pauper (Mello-Leitão) and A. iheringi (Mello-Leitão). Four new species are described from Brazil: A. aeolicus, A. atlanticus, A. centralis and A. gandarela.

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We propose a new approach for identification of areas of endemism, the Geographical Interpolation of Endemism (GIE), based on kernel spatial interpolation. This method differs from others in being independent of grid cells. This new approach is based on estimating the overlap between the distribution of species through a kernel interpolation of centroids of species distribution and areas of influence defined from the distance between the centroid and the farthest point of occurrence of each species. We used this method to delimit areas of endemism of spiders from Brazil. To assess the effectiveness of GIE, we analyzed the same data using Parsimony Analysis of Endemism and NDM and compared the areas identified through each method. The analyses using GIE identified 101 areas of endemism of spiders in Brazil GIE demonstrated to be effective in identifying areas of endemism in multiple scales, with fuzzy edges and supported by more synendemic species than in the other methods. The areas of endemism identified with GIE were generally congruent with those identified for other taxonomic groups, suggesting that common processes can be responsible for the origin and maintenance of these biogeographic units.

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The Brazilian Caatinga is part of the seasonally dry tropical forests, a vegetation type disjunctly distributed throughout the Neotropics. It has been suggested that during Pleistocene glacial periods, these dry forests had a continuous distribution, so that these climatic shifts may have acted as important driving forces of the Caatinga biota diversification. To address how these events affected the distribution of a dry forest species, we chose Sicarius cariri, a spider endemic to the Caatinga, as a model. We studied the phylogeography of one mitochondrial and one nuclear gene and reconstructed the paleodistribution of the species using modelling algorithms. We found two allopatric and deeply divergent clades within S. cariri, suggesting that this species as currently recognized might consist of more than one independently evolving lineage. Sicarius cariri populations are highly structured, with low haplotype sharing among localities, high fixation index and isolation by distance. Models of paleodistribution, Bayesian reconstructions and coalescent simulations suggest that this species experienced a reduction in its population size during glacial periods, rather than the expansion expected by previous hypotheses on the paleodistribution of dry forest taxa. In addition to that, major splits of intraspecific lineages of S. cariri took place in the Pliocene. Taken together, these results indicate S. cariri has a complex diversification history dating back to the Tertiary, suggesting the history of dry forest taxa may be significantly older than previously thought.

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