Micaela Nicoletta

The name Grammostola australis Gerschman et Schiapelli, 1948, syn. resurr. is herein resurrected from synonymy with G. inermis Mello-Leitão, 1941, based on morphological and molecular evidence. The holotypes of both species are redescribed, and the female of G. australis is described for the first time. Diagnoses of these species are also provided. Phylogenetic analyses recovered G. inermis as a distinct lineage from G. australis, suggesting that both species are more closely related to Brazilian and Uruguayan species of the genus Grammostola Simon, 1892, than to other Argentinean species. Similarly, Chilean species appear distinct from other Grammostola species, indicating that the Andes act as a geographical barrier.

The family Pycnothelidae comprises medium to small-sized spiders that construct silk tubes under stones or logs or dig burrows in open environments. In Argentina, Acanthogonatus centralis Goloboff, 1995 and Stenoterommata platensis Holmberg, 1881 are two species commonly found in central region, associated to the mountainous grasslands or to the La Plata River Basin. The Tandilia mountainous grassland is an extended belt located southeastern Buenos Aires province, Argentina. Although some pycnothelid spiders are distributed close to this mountainous system, they are not recorded in Tandilia. Through niche modeling we attempt to evaluate the influence of bioclimatic variables in shaping the distribution of these species and explore their absence in the mountainous belt under past, present and future climatic conditions. We found that Tandilia is a non-suitable area for the establishment of the populations of these species with the exception of Stenoterommata platensis under a future scenario of climatic change.

Reportamos un nuevo registro en la distribución geográfica de Chaco tucumana en la provincia de Salta, norte de Argentina. Es la localidad más al norte conocida para la especie. Además, presentamos datos sobre la historia natural de la especie y mapas de distribución incluyendo comentarios de las provincias biogeográficas y ecorregiones involucradas.

A new species of Linothele Karsch, 1879 from southern Peru is described and illustrated, L. mubii sp. nov. The new species can be distinguished from other species of the genus by scopulation in combination with the morphology of copulatory organs.

The tarantula genus Tmesiphantes Simon, 1892 includes 20 valid species distributed in Argentina and Brazil. These spiders are distinguished from other Theraphosinae genera by the presence of an incrassate femur III, more evident in males, urticating hair types III and IV on the abdominal dorsum, few cuspules on the labium (0 to 30), maxillae with a maximum of 200 cuspules and sternum rounded. From recent examination of material from Peru, we discovered specimens that share all the morphological characters of Tmesiphantes, but did not fit with any known species. In the present study T. intiyaykuy sp. nov. is diagnosed, described, and illustrated. This new species resembles T. caymmii in the circular patch with stiff setae on midventral abdomen but can be distinguished by the shape of the palpal bulb and spermathecae. Also, we performed a phylogenetic analysis using morphological characters to infer the taxonomic placement of the new species. The analysis included 26 terminal species and 36 characters. Representatives of Tmesiphantes formed a monophyletic group and T. intiyaykuy sp. nov. is close related with T. caymmii. A dichotomous identification key and a geographic distribution map were constructed for recognized species of Tmesiphantes.