Ivan L F Magalhaes

• PhD in Biological Sciences
• Investigador Asistente CONICET at Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"

Ochyroceratinae is a diverse subfamily that has received fragmentary taxonomic attention. We here present a survey of Cuban species belonging to this group and examine the results in the light of recent phylogenies of the family. Three new species belonging to Ochyrocera Simon, 1892, are named: Ochyrocera luisarmasi sp. nov., O. maestra sp. nov. an...

Pikelinia schiapelliae, a new spider species from sandy habitats in Argentina and Uruguay (Araneae: Filistatidae). The genus Pikelinia is the main representative of the spider family Filistatidae in South America, with 19 named species. However, much of its diversity remains to be discovered. In this manuscript, we describe Pikelinia schiapelliae M...

In recent years, several endemic species of Loxosceles, violin spiders, have been described from the North-Central Chile biodiversity hotspot, some of which have ambiguous placement within the species groups of the genus. In a recent expedition to the Atacama region, we collected male specimens representing new records of two recently described spe...

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 current...

The Neotropical region is the most diverse on the planet, largely due to its mosaic of tropical rainforests. Multiple tectonic and climatic processes have been hypothesized to play a role in generating this diversity; these include Andean orogeny, closure of the Panama Isthmus, the hypothesized GAARlandia land bridge, and putative historical connec...

Geometric regularity of spider webs has been intensively studied in orb-weaving spiders, although it is not exclusive of orb weavers. Here, we document the geometrically regular, repetitive elements in the webs of the non-orb-weaving groups Leptonetidae and Telemidae for the first time. Similar to orb weavers, we found areas with regularly spaced p...

Recluse or violin spiders in the genus Loxosceles (Scytodoidea: Sicariidae) are a diverse group (~140 extant species) including medically important species and distributed mainly in the Americas, Africa, and the Mediterranean region. In addition, this genus includes three fossil species from Miocene Dominican amber. Here we revise the taxonomy of t...

A new species, Tekellina araucana sp. n., is described from from Chile and Argentina. Detailed morphological data from the spinnerets and male palp of T. araucana sp. n. and Tekellina sadamotoi Yoshida & Ogata, 2016 is provided. A new diagnostic character of Tekellina Levi, 1957, a row of bottle-like modified setae between the anal tubercle and the...

We describe a new troglophilic species of Filistata, F. betarif sp. nov. , collected from two caves in central Israel, by using light and electron microscopy and by DNA barcoding of the cytochrome c oxidase subunit I (COI) gene. Sequences of this gene show more than 15% of divergence between the new species and its sibling, F. insidiatrix (Forsskål...

In this study, we investigated the chromosomes of three species of Sicarius spiders from the Brazilian Caatinga, using classical and molecular cytogenetic techniques. Based on the phylogenetic approach, we also discussed about the variation of diploid number, types of sex chromosome system and changes in the localization of ribosomal genes of Scyto...

Filistatids, the crevice weavers, are an ancient family of cribellate spiders without extant close relatives. As one of the first lineages of araneomorph spiders, they present a complicated mixture of primitive and derived characters that make them a key taxon to elucidate the phylogeny of spiders, as well as the evolution of phenotypic characters...

The genus Labahitha has hitherto comprised two species from peninsular Malaysia and Christmas Island (Australia). We here demonstrate that the genus is widespread in islands and territories across the Indian and Pacific Oceans, including the following species that have been previously assigned to other filistatid genera: Labahitha marginata (Kishid...

New taxonomic considerations in the spitting spider family Scytodidae Blackwall, 1864 are proposed. Here, the family is considered to include two subfamilies: Scytodinae Blackwall, 1864, comprising the genera Scytodes Latreille, 1804 and Dictis L. Koch, 1872, and Scyloxinae subfam. n., comprising the genera Scyloxes Dunin, 1992 and Stedocys Ono, 19...

Deserts are characterized by unpredictable precipitation and extreme temperatures. Their fauna and flora are sensitive to anthropogenic environmental changes, and often recover slowly from environmental disasters. The effects of oil spills on the biota of desert regions, however, have scarcely been studied. We predicted that terrestrial invertebrat...

Spiders are a highly diversified group of arthropods and play an important role in terrestrial ecosystems as ubiquitous predators, which makes them a suitable group to test a variety of eco-evolutionary hypotheses. For this purpose, knowledge of a diverse range of species traits is required. Until now, data on spider traits have been scattered acro...

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...

Psilodercidae contains some 200 known extant species of small spiders that live in tropical rainforests and caves and is mainly restricted to the Oriental biogeographic realm. Interestingly, at least ten different fossil species have been described from inclusions in Late Cretaceous Burmese amber. This suggests the family has been diversifying in t...

The Filistatinae genus Sahastata Benoit, 1968 is distributed in arid and semi-arid areas, from westernmost Sahara to India, and includes seven known species. Four of these are only known from one sex, including Sahastata nigra (Simon, 1897), the type species. Here we present the first description of a male of this species collected near the type lo...

Despite extensive taxonomic work on the Neotropical fauna of the spider genus Micrathena Sundevall, for 27 out of 117 (23%) species only the female morphology has been described, and some of the previously hypothesized male-female matches have been proven erroneous. This work provides new insight about sex matching in two species: Micrathena ruschi...

The common ancestor of spiders likely used silk to line burrows or make simple webs, with specialized spinning organs and aerial webs originating with the evolution of the megadiverse "true spiders" (Araneomorphae). The base of the araneomorph tree also concentrates the greatest number of changes in respiratory structures, a character system whose...

Studies in evolutionary biology and biogeography increasingly rely on the estimation of dated phylogenetic trees using molecular clocks. In turn, the calibration of such clocks is critically dependent on external evidence (i.e. fossils) anchoring the ages of particular nodes to known absolute ages. In recent years, a plethora of new fossil spiders,...

Phylogenetic niche conservatism (PNC) shapes the distribution of organisms by constraining lineages to particular climatic conditions. Conversely, if areas with similar climates are geographically isolated, diversification may also be limited by dispersal. Neotropical xeric habitats provide an ideal system to test the relative roles of climate and...

It is now generally accepted that we are going through a major mass extinction event that is causing biodiversity loss at alarming rates (Barnosky et al. 2011). We also know that many species remain to be formally described (e.g. Huber 2014), and concerns have been raised as to whether we will be able to document these before they go extinct (Coste...

ABSTRACT. The Malagasy species of the filistatid spider genus Andoharano Lehtinen are revised. The four previously known species, all from caves, are redescribed and have their type material illustrated. The paratypes of A. milloti Legendre are not conspecific with its holotype and are herein described as A. rollardae sp. nov. The first epigean rep...

Filistatidae is one of the most phylogenetically enigmatic spider groups, and the genus Kukulcania Lehtinen includes the commonest representatives of the family. Its type species, K. hibernalis (Hentz, 1842), remains a favorite candidate for studies on spider phylogeny and comparative morphology. However, little is known about the taxonomy, species...

Cave organisms are often relictual, ancient lineages that conserve characters no longer represented in their closest relatives. I here present a new species of Filistatidae from Mexican caves with a notable suite of characters that preclude its placement in any of the filistatid genera currently recorded from North America. A detailed study of its...

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...

The monotypic genus Mystes Bristowe, 1938, and its type species, M. oonopiformis Bristowe, 1938, are redescribed based on the neotype male (designated here) and several females. The male is described for the first time and the female endogyne is illustrated for the first time. Morphological analysis reveals that the genus belongs to the Prithinae a...

Filistatids represent an antique lineage of araneomorph spiders which are most diverse in arid and semiarid regions of the globe. Phylogenetic relationships among its genera are still largely unexplored, and previous studies disagree on the position of the North American Filistatinella Gertsch & Ivie, 1936, which could either be the sister group of...

Arthropod silk is among the most remarkable materials produced by animals, and is diverse in chemical composition and strand morphology. Different types of silk are produced by different spinning processes, and spiders show the greatest diversity in both. Extremely flattened silk strands with exceptional properties are spun by recluse spiders (Loxo...

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...

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...

The spider genus Ianduba is known from seven species, all restricted to the Brazilian Atlantic rainforest, a biodiversity hotspot. The genitalic morphology of these spiders is rather peculiar and they have been considered incertae sedis in Corinnidae. We present novel morphological data for the genus, including scanning electronic microscopy images...

I present an update on the taxonomy of the filistatid genera Wandella Gray and Yardiella Gray, both endemic to Australia. Two new species are described: Wandella grayi sp. nov., known from Queensland, and Wandella infernalis sp. nov., known from a single cave in Western Australia. The male of Wandella australiensis (L. Koch) and the females of Wand...

Three new species of the genus Misionella are described from Brazil: M. carajas sp. n. and M. aikewara sp. n. from caves in the states of Pará and Tocantins and M. pallida sp. n. from natural and synanthropic dry areas in the states of Piauí, Maranhão, Rio Grande do Norte and Bahia. These species seem to belong to a distinct group within the genus;...

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...

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...

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...

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...

In this paper, M. yanomami n. sp., from Brazilian Amazonia, Chaetacis bandeirante n. sp., from Central Brazil, and the males of M. gaujoni Simon, 1897 and M. ruschii (Mello-Leitão, 1945) n. comb. , respectively from Ecuador and Brazil, are described and illustrated for the first time. An ontogenetic series of the last development stages of both sex...

Pozonia Schenkel, 1953 is a genus of Neotropical orb-weaving spiders that currently includes four species, three of which are known only from females. In this paper, the male of Pozonia bacillifera (Simon, 1897) is described and illustrated for the first time, based on a specimen from Nova Lima, state of Minas Gerais, Brazil. It differs from the ma...

Biological knowledge is represented in scientific literature that often describes the function of genes/proteins (bioentities) in terms of their interactions (biointeractions). Such bioentities are often related to biological concepts of interest that are specific of a determined research field. Therefore, the study of the current literature about...