Evolution and comparative morphology of raptorial feet in spiders.

Spiders are among the most diverse animals, which developed different morphological and behavioral traits for capturing prey. We studied the anatomy and functionality of the rare and apomorphic raptorial spider feet using 3D reconstruction modeling, among other imaging techniques. The evolutionary reconstruction of the raptorial feet (tarsus plus pretarsus) features using a composite tree of spiders, indicating that similar traits emerged three times independently in Trogloraptoridae, Gradungulinae, and Doryonychus raptor (Tetragnathidae).

Sequence Capture Phylogenomics of True Spiders Reveals Convergent Evolution of Respiratory Systems.

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 evolution is still poorly understood, and that might be related to the evolution of silk glands. Emphasizing a dense sampling of multiple araneomorph lineages where tracheal systems likely originated, we gathered genomic-scale data and reconstructed a phylogeny of true spiders.

Systematics and evolution of ground spiders revisited (Araneae, Dionycha, Gnaphosidae).

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.

-Comparative spigot ontogeny across the spider tree of life.

Spiders are well known for their silk and its varying use across taxa. Very few studies have examined the silk spigot ontogeny of the entire spinning field of a spider. Historically the spider phylogeny was based on morphological data and behavioral data associated with silk.

The spider tree of life: phylogeny of Araneae based on target-gene analyses from an extensive taxon sampling.

We present a phylogenetic analysis of spiders using a dataset of 932 spider species, representing 115 families (only the family Synaphridae is unrepresented), 700 known genera, and additional representatives of 26 unidentified or undescribed genera. Eleven genera of the orders Amblypygi, Palpigradi, Schizomida and Uropygi are included as outgroups. The dataset includes six markers from the mitochondrial (12S, 16S, COI) and nuclear (histone H3, 18S, 28S) genomes, and was analysed by multiple methods, including constrained analyses using a highly supported backbone tree from transcriptomic data.

Rounding up the usual suspects: a standard target-gene approach for resolving the interfamilial phylogenetic relationships of ecribellate orb-weaving spiders with a new family-rank classification (Araneae, Araneoidea).

We test the limits of the spider superfamily Araneoidea and reconstruct its interfamilial relationships using standard molecular markers. The taxon sample (363 terminals) comprises for the first time representatives of all araneoid families, including the first molecular data of the family Synaphridae. We use the resulting phylogenetic framework to study web evolution in araneoids.

A taxonomic revision of the ground spiders of the genus Apopyllus (Araneae: Gnaphosidae).

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 and by the presence of paramedian epigynal pockets and of an anterior ridge on the epigynum. The RTA characters are important in species taxonomy but the complex shape and variation of the RTA hampers identification, especially regarding the two most common species: A.

Spider phylogenomics: untangling the Spider Tree of Life.

Spiders (Order Araneae) are massively abundant generalist arthropod predators that are found in nearly every ecosystem on the planet and have persisted for over 380 million years. Spiders have long served as evolutionary models for studying complex mating and web spinning behaviors, key innovation and adaptive radiation hypotheses, and have been inspiration for important theories like sexual selection by female choice. Unfortunately, past major attempts to reconstruct spider phylogeny typically employing the "usual suspect" genes have been unable to produce a well-supported phylogenetic framework for the entire order.

Revision of emmenomma simon (amaurobiidae, macrobuninae).

The genus Emmenomma is revised and now includes three species from Southern Chile, Argentina and Falkland Islands (Islas Malvinas). The type species Emmenomma oculatum is redescribed and considered a senior synonym of E. beauchenicum.

Why is Madagascar special? The extraordinarily slow evolution of pelican spiders (Araneae, Archaeidae).

Although Madagascar is an ancient fragment of Gondwana, the majority of taxa studied thus far appear to have reached the island through dispersal from Cenozoic times. Ancient lineages may have experienced a different history compared to more recent Cenozoic arrivals, as such lineages would have encountered geoclimatic shifts over an extended time period. The motivation for this study was to unravel the signature of diversification in an ancient lineage by comparing an area known for major geoclimatic upheavals (Madagascar) versus other areas where the environment has been relatively stable.

Systematics, phylogeny, and evolution of orb-weaving spiders.

The orb-weaving spiders (Orbiculariae) comprise more than 25% of the approximately 44,000 known living spider species and produce a remarkable variety of webs. The wheel-shaped orb web is primitive to this clade, but most Orbiculariae make webs hardly recognizable as orbs. Orb-weavers date at least to the Jurassic.

Phylogenetic placement of pelican spiders (Archaeidae, Araneae), with insight into evolution of the "neck" and predatory behaviours of the superfamily Palpimanoidea.

Phylogenetic relationships among archaeid spider lineages, as well as the placement of archaeids within the Araneomorphae, present a problem in the systematics of spiders. We investigate these relationships by broadly sampling taxa from the Araneomorphae and superfamily Palpimanoidea, as well as from extant and fossil archaeid lineages. Using parsimony and Bayesian methods we perform a total-evidence analysis that includes 126 morphological characters and over 4000 bases from one mitochondrial and three nuclear molecular markers.

Treating fossils as terminal taxa in divergence time estimation reveals ancient vicariance patterns in the palpimanoid spiders.

Incorporation of fossils into biogeographic studies can have a profound effect on the conclusions that result, particularly when fossil ranges are nonoverlapping with extant ranges. This is the case in archaeid spiders, where there are known fossils from the Northern Hemisphere, yet all living members are restricted to the Southern Hemisphere. To better understand the biogeographic patterns of archaeid spiders and their palpimanoid relatives, we estimate a dated phylogeny using a relaxed clock on a combined molecular and morphological data set.

An extraordinary new family of spiders from caves in the Pacific Northwest (Araneae, Trogloraptoridae, new family).

The new spider genus and species Trogloraptor marchingtoni Griswold, Audisio & Ledford is described as the type of the new family Trogloraptoridae. The oblique membranous division of the basal segment of the anterior lateral spinnerets of Trogloraptor suggests that this haplogyne family is the sister group of the other Dysderoidea (Dysderidae, Oonopidae, Orsolobidae and Segestriidae). Trogloraptor is known only from caves and old growth forest understory in the Klamath-Siskiyou region of Oregon and California.

The velvet spiders: an atlas of the Eresidae (Arachnida, Araneae).

The family Eresidae C. L. Koch, 1850 is reviewed at the genus level.

Phylogeny of entelegyne spiders: affinities of the family Penestomidae (NEW RANK), generic phylogeny of Eresidae, and asymmetric rates of change in spinning organ evolution (Araneae, Araneoidea, Entelegynae).

Penestomine spiders were first described from females only and placed in the family Eresidae. Discovery of the male decades later brought surprises, especially in the morphology of the male pedipalp, which features (among other things) a retrolateral tibial apophysis (RTA). The presence of an RTA is synapomorphic for a large clade of spiders exclusive of Eresidae.

Phylogenetic relationships within an endemic group of Malagasy 'assassin spiders' (Araneae, Archaeidae): ancestral character reconstruction, convergent evolution and biogeography.

The phylogenetic relationships in an endemic group of Malagasy 'assassin spiders' (Araneae, Archaeidae: Eriauchenius) called the gracilicollis group, are inferred from mitochondrial 12S, 16S and COI DNA sequence data. Archaeid spiders of Madagascar have evolved varying degrees of elongation in the cephalic area. These molecular data support the monophyly of the gracilicollis group.

Linking of digital images to phylogenetic data matrices using a morphological ontology.

Images are paramount in documentation of morphological data. Production and reproduction costs have traditionally limited how many illustrations taxonomy could afford to publish, and much comparative knowledge continues to be lost as generations turn over. Now digital images are cheaply produced and easily disseminated electronically but pose problems in maintenance, curation, sharing, and use, particularly in long-term data sets involving multiple collaborators and institutions.