An unusual new species of Trechona

postgraduate programme 'Comparative Biology', University of Sao PauloCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Trechona diamantina sp. nov. is described from quartzite caves in Diamantina, central Minas Gerais State, Brazil. This represents the largest cavernicolous mygalomorph population ever recorded. The new species is the first Trechona recorded from a xeric habitat, namely the Rocky Fields on the Diamantina Plateau. T. diamantina sp. nov. is closely related to T. uniformis, both species possessing elongated male and female copulatory organs and both constructing distinct funnel-webs and sheet-webs in quartzite formations. T. diamantina sp. nov. is distinct in possessing less elongated embolus and receptacula seminis. A key for all valid species of the genus is given

Biogeography of New World Tarantulas

Biogeography is a multidisciplinary field that is concerned with delimit- ing and explaining the geographic distributions of organisms in space and time. Due to their distribution patterns and interesting biology (e.g., ancient lineage with a nearly cosmopolitan distribution, sedentary lifestyle with limited dispersal capabili- ties), tarantulas are an appealing taxonomic group for addressing a variety of bio- geographic questions concerning the Earth’s history. In this chapter, we discuss some biogeographic basic concepts, delve into the distribution patterns of New World tarantulas, and explore some of the historical explanations that may have led to these distributions. We mostly review and highlight the results of recent studies but also include personal observations and unpublished data. The distributions of higher-level taxonomic groups (subfamilies and tribes) are described and we detail their latitudinal and elevational limits. We also review the distributions of groups with unique insular habitats such as those found on islands surrounded by seas, forested “islands” surrounded by “seas” of deserts, and caves. Furthermore, we dis- cuss the distribution of some unique morphological characters of taxonomic impor- tance such as urticating setae. Finally, we review a handful of studies that have explicitly investigated the biogeography of New World tarantulas using a variety of different analytical methods.Fil: Perafán, Carlos. Universidad de la República. Facultad de Ciencias; UruguayFil: Ferretti, Nelson Edgardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: Hendrixson, Brent E.. Millsaps College. Department Of Biology; Estados Unido