Phylogenomics of Scorpions Reveal Contemporaneous Diversification of Scorpion Mammalian Predators and Mammal-Active Sodium Channel Toxins.

Scorpions constitute a charismatic lineage of arthropods and comprise more than 2500 described species. Found throughout various tropical and temperate habitats, these predatory arachnids have a long evolutionary history, with a fossil record that began in the Silurian. While all scorpions are venomous, the asymmetrically diverse family Buthidae harbors nearly half the diversity of extant scorpions, and all but one of the 58 species that are medically significant to humans.

Characterization of the fluorescence intensity and color tonality in the exoskeleton of scorpions.

Scorpions are a mesodiverse and nocturnal group of arachnids inhabiting most biomes worldwide. Different species of scorpions have divergent adaptations to the substrate they live in, but most of them share an intriguing characteristic: their exoskeleton contains fluorophores that emit blue-greenish fluorescence under ultraviolet radiation. Although there are some reports in the literature on the study of fluorescence in scorpions, the biological functionality of this light emission is currently unknown and is under debate.

A new species of Centruroides (Scorpiones, Buthidae) from Colima, Mexico.

As part of an ongoing survey of scorpion diversity in Colima, Mexico, the isolated mountain Cerro Grande, part of the Biosphere Reserve Sierra de Manantlán, was investigated. Centruroides possanii sp. nov.

Structural and functional characterization of toxic peptides purified from the venom of the Colombian scorpion Tityus macrochirus.

The soluble venom of the scorpion Tityus macrochirus was separated by chromatographic procedures and three homogeneous peptides were obtained and their primary structures were determined. They were called: Tma1-Tma3, from the abbreviated name of the scorpion. Tma1 is a peptide containing 65 amino acids with four disulfide linkages and a molecular weight of 7386.

Phylogenomics facilitates stable scorpion systematics: Reassessing the relationships of Vaejovidae and a new higher-level classification of Scorpiones (Arachnida).

The Neartic family Vaejovidae (Scorpiones: Chactoidea) has long been treated as a diverse and systematically cohesive group of scorpions, but its monophyly and relationship to other scorpion families have historically been questioned. Morphological data have supported its monophyly and a variety of phylogenetic placements within the superfamily Chactoidea. Recent phylogenomic analyses have instead recovered vaejovids as polyphyletic (albeit with minimal taxonomic sampling) and Chactoidea as paraphyletic.

The male sexual apparatus in the order Scorpiones (Arachnida): a comparative study of functional morphology as a tool to define hypotheses of homology.

Background: Insemination in scorpions is carried out by means of a partly sclerotized structure, the spermatophore, which is composed of two separate halves, the hemispermatophores. In most genera these reproductive structures can be used to differentiate species. However, many taxa such as the genus and the family Diplocentridae lack the morphological diversity observed in the copulatory organs of many other arthropods, rendering them useless for species level taxonomy.

A new species of Diplocentrus (Scorpiones: Diplocentridae) with punctate pedipalp surfaces, a diagnostic character within the "mexicanus" group.

Diplocentrus duende n. sp. is described based on adult males collected from a locality in the Tehuacán-Cuicatlán Valley, Mexico.

Evidence of duplicated Hox genes in the most recent common ancestor of extant scorpions.

Scorpions (order Scorpiones) are unusual among arthropods, both for the extreme heteronomy of their bauplan and for the high gene family turnover exhibited in their genomes. These phenomena appear to be correlated, as two scorpion species have been shown to possess nearly twice the number of Hox genes present in most arthropods. Segmentally offset anterior expression boundaries of a subset of Hox paralogs have been shown to correspond to transitions in segmental identities in the scorpion posterior tagmata, suggesting that posterior heteronomy in scorpions may have been achieved by neofunctionalization of Hox paralogs.

New Fossil Scorpion from the Chiapas Amber Lagerstätte.

A new species of scorpion is described based on a rare entire adult male preserved in a cloudy amber from Miocene rocks in the Chiapas Highlands, south of Mexico. The amber-bearing beds in Chiapas constitute a Conservation Lagerstätte with outstanding organic preservation inside plant resin. The new species is diagnosed as having putative characters that largely correspond with the genus Tityus Koch, 1836 (Scorpiones, Buthidae).

Phylogeny of the North American vaejovid scorpion subfamily Syntropinae Kraepelin, 1905, based on morphology, mitochondrial and nuclear DNA.

The first rigorous analysis of the phylogeny of the North American vaejovid scorpion subfamily Syntropinae is presented. The analysis is based on 250 morphological characters and 4221 aligned DNA nucleotides from three mitochondrial and two nuclear gene markers, for 145 terminal taxa, representing 47 species in 11 ingroup genera, and 15 species in eight outgroup genera. The monophyly and composition of Syntropinae and its component genera, as proposed by Soleglad and Fet, are tested.

The male of Megacormusgranosus (Gervais, 1844) with comments on its hemispermatophore (Scorpiones, Euscorpiidae).

The male of Megacormusgranosus is described for the first time and the female redescribed. A homology scheme proposed recently is applied to hemispermatophore structures. The specimens were collected in an oak forest from Pico de Orizaba Volcano at an average altitude of 2340 m.

Phylogenomic resolution of scorpions reveals multilevel discordance with morphological phylogenetic signal.

Scorpions represent an iconic lineage of arthropods, historically renowned for their unique bauplan, ancient fossil record and venom potency. Yet, higher level relationships of scorpions, based exclusively on morphology, remain virtually untested, and no multilocus molecular phylogeny has been deployed heretofore towards assessing the basal tree topology. We applied a phylogenomic assessment to resolve scorpion phylogeny, for the first time, to our knowledge, sampling extensive molecular sequence data from all superfamilies and examining basal relationships with up to 5025 genes.