Dr. Ivan L. F. Magalhaes
Projects
My main goals are describing spider biodiversity, understanding the phylogenetic relationships among spiders, and using this systematic basis for answering broader questions in biogeography and evolutionary biology. For this, I employ several skills from a systematist's toolkit such as: (a) fieldwork and collections-based research, (b) morphology studies using optical and electronic microscopy and micro-computed tomography, (c) scientific illustration and photography, (d) DNA sequencing, (e) methods for inferring phylogenies and estimating divergence ages, (f) phylogenetic comparative methods and (g) basic statistics and programming.
Below, there is information about ongoing or past research projects. Results of some of these projects have been partially or fully published as scientific articles (see Publications).
Systematics of crevice-weavers (Filistatidae)
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Filistatidae are a globally distributed spider family of medium diversity (~185 described species as of 2021), mostly found in arid and semi-arid areas of the globe. They have a curious mix of primitive and derived characters and are key to understanding the evolution of early spiders. I started studying their diversity as part of my doctoral research, aiming at revising the taxonomy of (mainly) the representatives of the American continent, as well as proposing a new phylogenetic hypothesis for the family.
Systematics and evolution of Synspermiata
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Sysnpermiata are one of the major clades of spiders, containing some 5500 species and notorious members such as cellar spiders, recluse spiders and globin spiders. They also have a rich fossil record, especially during the Mesozoic. Part of my postdoctoral research involves understanding the phylogenetic relationships among the 17 living Synspermiata families and the fossil representatives, as well as understanding the evolution of the genital system in this group.
Systematics and biogeography of sand spiders (Sicarius)
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Sand spiders live only in arid and semi-arid habitats in Africa and South and Central America. My previous efforts have established a solid taxonomic basis for this group, revising the ~20 American species and uncovering the phylogenetic relationships among them. This allows using these spider as models for understanding the historical biogeography of Neotropical xeric biomes, such as deserts and tropical dry forests.
Systematics and evolution of spiny orb weavers (Micrathena)
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Micrathena is a group of orb-weavers with some 120 species found in forests in the American continent. Males are small and unremarkable, while females are larger, and may be colorful and bear long abdominal spines. I investigate the phylogeny of this genus, which forms the basis for studies of biogeography and evolution of sexual dimorphism and abdominal spines. I also focus on describing the males of the several species known only by females.
