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Adalberto J. Santos

Adalberto J. Santos

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99
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Publications

Publications (99)
Article
A new species of trechaleid spider, Paratrechalea murphyi sp. n. (), is diagnosed, described. and illustrated. The species is based on the male and female specimens collected 20 years ago in a conservation unit in the Cerrado biome of Brazil. An attempt to find new specimens in the type locality and in a few nearby locations failed, raising the pos...
Article
Full-text available
Event-based biogeographic methods, such as dispersal-extinction-cladogenesis, have become increasingly popular for attempting to reconstruct the biogeographic history of organisms. Such methods employ distributional data of sampled species and a dated phylogenetic tree to estimate ancestral distribution ranges. Because the input tree is often a sin...
Article
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Zootaxa published more than a thousand papers on Araneae from 2002 to the present, including descriptions of 3,833 new spider species and 177 new genera. Here we summarise the key contributions of Zootaxa to our current knowledge of global spider diversity. We provide a historical account of the researchers that have actively participated as editor...
Preprint
Full-text available
Event-based biogeographic methods, such as dispersal-extinction-cladogenesis, have become increasingly popular for attempting to reconstruct the biogeographic history of organisms. Such methods employ distributional data of sampled species and a dated phylogenetic tree to estimate ancestral distribution ranges. Because the input tree is often a sin...
Article
Full-text available
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...
Article
Spiders may be good models for studying the evolution of genitalia given their peculiar copulatory mechanism. Gnaphosidae, in particular, have remarkable diversity in copulatory apparatus. The family contains species with bipartite and tripartite palps. Previous studies suggest intermediate palp complexity as the ancestral condition, with an evolut...
Article
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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.
Article
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Loxosceles Heineken & Lowe, 1832 spiders are infamous for their medical importance, but a taxonomic picture of the genus is still far from complete. In this study, the Chilean species of Loxosceles are described and mapped. The males of Loxosceles surca Gertsch, 1967 and L. coquimbo Gertsch, 1967 are described for the first time. Three new species...
Article
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 mo...
Chapter
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The infraorder Araneomorphae comprises more than nine-tenths of spider diversity, including most of the better known web-weaving spiders. As observed for other taxa, the group is particularly diverse in the Neotropics, where it can be find in any terrestrial ecosystem. In this chapter we synthesize the current taxonomic and biogeographic knowledge...
Article
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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 angiosp...
Article
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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 iden...
Article
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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 distribut...
Article
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The knowledge on the geographical distribution of species is essential for building biogeographical and macroecological hypotheses. However, information on this regard is not distributed uniformly in space and usually come from biased sampling. The aim of this study is to quantify the influence of spatial distribution of sampling effort on the asse...
Article
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Sicariids are an infamous spider family containing two genera: the poorly known Sicarius Walckenaer and the medically important Loxosceles Heineken & Lowe. We present the first broad survey of the morphology of the family from a phylogenetic perspective in order to resolve its relationships. We scored morphological, behavioural and venom feature da...
Article
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Many orb-weaving spiders exhibit remarkable sexual dimorphism, hampering the matching of males and females in taxonomic studies. This is the case for the spiny Micrathena spiders, a species-rich Neotropical genus with 27% of its species known from a single sex. In this paper we document several undescribed Micrathena specimens, and test whether the...
Article
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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 mai...
Article
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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...
Article
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The knowledge of biodiversity facets such as species composition, distribution and ecological niche is fundamental for the construction of biogeographic hypotheses and conservation strategies. However, the knowledge on these facets is affected by major shortfalls, which are even more pronounced in the tropics. This study aims to evaluate the effect...
Technical Report
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LINK VÍDEO: https://www.youtube.com/watch?v=nRz4Z2W_PeQ Tutorial de uso do método de identificação de áreas de endemismo GIE. Esta versão do vídeo está com uma importante correção: o programa de calculo da distância entre o centroide e o ponto mais distante está apresentando alguns problemas. Assim, neste vídeo eu mostro como fazer esse calculo no...
Article
Full-text available
Documenting how diversity patterns vary at fine-and broad scales may help answer many questions in theoretical and applied ecology. However, studies tend to compare diversity patterns at the same scale and within the same taxonomic group, which limits the applicability and generality of the results. Here, we have investigated whether vegetation-dwe...
Article
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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 cen...
Article
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Protected areas are essential for the maintenance of biodiversity, but defining criteria for prioritizing areas to conserve is not an easy task. In general, selection has been based on species richness and endemism of plants and vertebrates; however, these do not necessarily match invertebrate data, hence the need of using other groups in conservat...
Article
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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 diver...
Article
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A new genus of goblin spiders, Simlops, is proposed for 15 species found in Brazilian and Colombian Amazonia and southern Caribbean (Venezuela and Guyana). The new genus belongs to the Scaphiella complex, a group of Neotropical genera that share a sexually dimorphic condition in which the abdominal dorsal scutum is present in males but absent in fe...
Article
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In this paper we revise the species of Sicarius (Araneae: Sicariidae) from the Brazilian Caatinga, the largest tropical dry forest nucleus in the world. We redescribe, designate a neotype and provide new records for Sicarius tropicus (Mello- Leitão, 1936), the only species previously known from the region, and describe three new species: S. cariri...
Book
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APRESENTAÇÃO Este livro é produto do esforço coletivo dos pesquisadores das instituições do Nordeste que participaram ativamente do trabalho de inventário do projeto PPBio Semiárido, assim como de seus estudantes de Iniciação Científica, Pós-graduandos nos níveis de Mestrado e Doutorado, bolsistas do PPBio e colaboradores externos de outras institu...
Article
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Three new species of the spider genus Philoponella Mello-Leitão, 1917 are described: Philoponella opelli n. sp. from Brazil and Ecuador, and Philoponella fluviidulcifis n. sp. , and Philoponella duopunctata n. sp. from Brazil. New records for Philoponella vittata (Keyserling, 1881), P. republicana (Simon, 1891), P. fasciata (Mello-Leitão, 1917) and...
Article
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Two species of the spider genus Kukulcania are known from South America. Kukulcania brevipes (Keyserling), originally described from Peru, is here diagnosed, illustrated and redescribed, with several new records provided for eastern Peru and northern Chile. The synanthropic Kukulcania hibernalis (Hentz) is illustrated and diagnosed, with several ne...
Article
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The current biodiversity crisis makes the quantification of the diversity and the description of organism distribution particularly pressing. Biological inventories are among the most effective ways to improve the knowledge about local biota, but they can be very time and money-consuming. The determination of adequate sampling effort and the select...
Article
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Two new species of Alpaida O.P.-Cambridge, 1889 are described based on male and female specimens from seven restinga areas from northeastern to southern Brazil. Alpaida teresinha sp. nov., from Rio de Janeiro and Espírito Santo, differs from other species of the genus in the wider lobe of the conductor, the concave median apophysis and with the pos...
Article
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Two new species of the arachnid order Schizomida, Rowlandius ubajara sp.nov. and Rowlandius potiguar sp.nov., are described based on both male and female specimens collected in caves from northeastern Brazil. Rowlandius ubajara is known only from the Ubajara Cave, in the state of Ceará; R. potiguar is recorded from 20 caves of the Apodi Limestone G...
Article
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In this study, 10 nominal species of Eustala Simon, 1895 are synonymized with other species of the genus, mostly based on matching males and females erroneously described as different species. Parawixia rimosa (Keyserling, 1892) is considered a senior synonym of Eustala decemtuberculata Caporiacco, 1955. Eustala isosceles Mello-Leitão, 1939 is tran...
Article
In this paper we revise the species of Sicarius (Araneae: Sicariidae) from the Brazilian Caatinga, the largest tropical dry forest nucleus in the world. We redescribe, designate a neotype and provide new records for Sicarius tropicus (Mello- Leitão, 1936), the only species previously known from the region, and describe three new species: S. cariri...
Article
Full-text available
The phylogenetic relationships amongst the New World spiny orb-weaving spiders Micrathena and Chaetacis were assessed through parsimony and Bayesian analyses of morphological characters. A total of 146 characters was scored for ten outgroup taxa and 37 Micrathena and four Chaetacis species. The results indicate that Chaetacis nests within Micrathen...
Article
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The new endemic goblin spider genus Predatoroonops is erected for 17 new soft-bodied oonopid species from Brazil: Predatoroonops schwarzeneggeri, sp. nov., is the type species of the genus, P. poncho, sp. nov., P. billy, sp. nov., P. valverde, sp. nov., P. blain, sp. nov., P. maceliot, sp. nov., P. anna, sp. nov., P. rickhawkins, sp. nov., P. dutch...
Article
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The Neotropical spider genus Neoxyphinus Birabén, 1953, is revised, comprising 10 species found from the West Indies to northern Argentina. The genus is characterized by a unique combination of characters, which include the presence of a set of low tubercles or large spikes on the posterior surface of carapace; male endites with an apical, retrolat...
Article
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Based on a survey of a wide variety of oonopid genera and outgroups, we hypothesize new synapomorphies uniting the Oonopidae (minus the South African genus Calculus Purcell, which is transferred to the Orsolobidae). The groundplan of the tarsal organ in Oonopidae is hypothe sized to be an exposed organ with a distinctive, longitudinal ridge origina...
Article
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A new endemic goblin spider genus Guaraguaoonops is erected to include two new soft-bodied oonopid species from Brazil: the type species, G. hemhem, distributed in the states of Maranhão, Piauí, and Ceará, and G. humbom, known only from Piauí. These spiders are unique among oonopids and easily diagnosed by the flattened carapace with a porrect clyp...
Article
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In this study we present a database of spiders described and registered from the Neotropical region between 1757 and 2008. Results are focused on the diversity of the group in the State of São Paulo, compared to other Brazilian states. Data was compiled from over 25,000 records, published in scientific papers dealing with Neotropical fauna. These r...