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The 'giant hairy scorpions', genus Hadrurus Thorell, are the largest and most conspicuous scorpions in North America, but their systematics has long been confused. A new genus, Hoffmannihadrurus Fet et al. was recently created to accommodate the two species endemic to mainland Mexico, Hadrurus aztecus Pocock and Hadrurus gertschi Soleglad. In the present contribution, we review the taxonomic history of Hadrurus, re-evaluate the phylogenetic relationships among its component species with an analysis based on morphological characters and a taxon sample representing the known morphological variation, and assess the validity of the new genus. Seven independent analyses of the morphological character matrix, under weighting regimes that minimised length as well as those that maximised fit, each located a single most parsimonious tree with the following scheme of relationships: (Iurus ((Caraboctonus + Hadruroides) (H. aztecus ((H. gertschi + H. pinteri) (H. concolorous + H. hirsutus)) ((H. obscurus + H. spadix) (H. a. arizonensis (H. a. austrinus + H. a. pallidus)))))). This topology supports the monophyly of Caraboctoninae, Caraboctonini, Hadrurini, the 'arizonensis' subgroup, H. arizonensis and H. concolorous. It does not support the monophyly of Hoffmannihadrurus, Hadrurus, the 'aztecus' group, the 'hirsutus' group, and the 'hirsutus' subgroup, all of which were rendered paraphyletic by the grouping of H. gertschi with H. pinteri, rather than with H. aztecus. The results unequivocally demonstrate that the creation of a new genus for the mainland Mexican species was unfounded. We therefore propose the following new synonymy: Hoffmannihadrurus Fet et al., 2004 = Hadrurus Thorell, 1876, syn. nov.

The aim of the present study was to analyze mass spectra of scorpions belonging to the genus Parabuthus(Pocock 1890) by means of matrix‐assisted laser desorption time‐of‐flight mass spectrometry (MALDI‐TOFMS) and to construct a species‐specific venom code for species identification. The venom compositions of sixteen Parabuthusspecies, occurring in southern Africa, were characterized using representative peaks in the molecular mass range of 6400–8400 Da. This mass range is characteristic for the typical long‐chain neurotoxins influencing sodium channels. Only a few of these peptides have been sequenced up to now. The impetus for development of these species‐specific profiles was the observation of unique, highly reproducible mass spectral peaks within a specific species. An identification label for all the different species could be found using a minimum number of peaks. MALDI‐TOFMS is therefore proposed as a complementary method to morphological and behavioural characteristics for species and ultimately subspecies discrimination. Copyright © 2002 John Wiley & Sons, Ltd.

S. A. Stockwell (1989, “Revision of the Phylogeny and Higher Classification of Scorpions (Chelicerata).” Univ. of California, Berkeley) proposed a cladogram and revised classification for the superfamily Scorpionoidea Latreille 1802 (comprising the families Bothriuridae, Diplocentridae, Heteroscorpionidae, Ischnuridae, and Scorpionidae), based on 47 morphological characters and 35 supraspecific terminal taxa, representing genera whose monophyly was implicitly assumed. Given the widespread practice of defining scorpion genera on the basis of plesiomorphic character states, the assumption of monophyly implicit in supraspecific terminal taxa reduces confidence in Stockwell's cladistic findings and, consequently, his revised suprageneric classification. A re-investigation of scorpionoid phylogeny is presented here, based on 115 morphological characters (including the characters used by Stockwell) and 71 exemplar species. The criterion of “maximal morphological diversity” was employed for exemplar selection. This approach provides a stronger test of monophyly than random exemplar selection. Sixteen cladistic analyses were performed on the scorpionoid data matrix, which varied in the use of equal, successive, or implied weights and in the additive or nonadditive treatment of multistate characters. The preferred hypothesis, a single most parsimonious tree obtained by analysis with equal weights and 13 ordered multistate characters, yielded the scheme of relationships: (Bothriuridae ((Heteroscorpionidae Urodacinae) ((Hemiscorpiinae Ischnuridae) (Diplocentridae Scorpioninae)))). On the basis of these results, revisions are proposed to the existing suprageneric classification of the Scorpionoidea, including new diagnoses, new descriptions, and an illustrated key to the families and subfamilies. Familial status is provided for the scorpionid subfamilies Hemiscorpiinae and Urodacinae.

Some male camel spiders (Arachnida: Solifugae) in the families Eremobatidae, Karschiidae, and Solpugidae have clusters of specialized conical or acuminate setae called papillae, on the ventral surface of the metatarsus of the pedipalps. We compared the overall structure of the papillae found on representatives of the three families using scanning electron microscopy (SEM). We examined the ultrastructure of these setae using transmission electron microscopy (TEM). We also used extracellular electrophysiological recording techniques to examine the electrical properties of these sensory structures and test the hypotheses that they function as mechanoreceptors, olfactory receptors, and chemoreceptors. We found similarities in the structure of papillae among genera within a family or distinct family-level differences in structure. Thus, the papillae are phylogenetically informative; similar within family but differing between families. TEM results demonstrated the cuticular wall of a papilla is divided into three sublayers: endo-, meso-, and exocuticle. Mechanoreceptive dendrites are evident at the base of the setal shaft. Other dendrites innervate the shaft of the papilla and penetrate through the cuticular layers near the setal apex. Two SEM images show what appear to be pores on the branches of the papillae, and we found what appears to be a pore tubule extending from the distal portion of the dendrites through the exocuticular layer. Electrophysiological data support the hypothesis that the papillae function as mechanoreceptors and provide no support for chemosensory, thermoregulatory, or hygroreceptive functions. Our data suggest that the papillae function as mechanoreceptors and may also function as chemoreceptors.

The refugial speciation model, or ‘species pump’, is widely accepted in the context of tropical biogeography and has been advocated as an explanation for present species distributions in tropical Western and Central Africa. In order to test this hypothesis, a phylogeny of the cryptic arachnid order Ricinulei, based on four nuclear and mitochondrial DNA markers, was inferred. This ancient clade of litter-dwelling arthropods, endemic to the primary forests of Western and Central Africa and the Neotropics, might provide insights into the mode and tempo of evolution in Africa. Twenty-six African ricinuleid specimens were sampled from eight countries spanning the distribution of Ricinulei on the continent, and analysed together with Neotropical samples plus other arachnid outgroups. The phylogenetic and molecular dating results suggest that Ricinulei diversified in association with the fragmentation of Gondwana. The early diversification of Ricinoidesin Western and Central Africa around 88 (±33) Ma fits old palaeogeographical events better than recent climatic fluctuations. Unlike most recent molecular studies, these results agree with fossil evidence, suggesting that refugia may have acted as ‘museums’ conserving ancient diversity rather than as engines generating diversity during successive episodes of climatic fluctuation in Africa.

The endemic southern African buthid genus Pseudolychas Kraepelin, 1911 is revised for the first time after an examination of the type material and a large number of additional specimens in southern African, European, and American collections. Three species are considered valid: Pseudolychas pegleri (Purcell, 1901), P. ochraceus (Hirst, 1911), and P. transvaalicus Lawrence, 1961. Pseudolychas pegleri nigrimanus Kraepelin, 1911 and P. multicarinatus Hewitt, 1925 (long regarded as P. pegleri multicarinatus) are newly synonymized with P. pegleri. The identity of P. ochraceus is verified by examination of the holotype. Many specimens identified as P. pegleri by previous authors are actually conspecific with P. ochraceus. Specimens of P. pegleri have also been misidentified as P. ochraceus. Revised diagnoses and descriptions are provided for the species of Pseudolychas, together with a key to their identification, brief summaries of their ecology and conservation status, and a distribution map plotting all known locality records. Pseudolychas ochraceus is suggested to be a parthenogenetic species. A phylogenetic analysis, based on 21 morphological characters and using exemplar species of eight buthid genera as outgroup taxa, confirms the monophyly of Pseudolychas and its placement as the sister group of a larger monophyletic group including Grosphus Simon, 1888, Parabuthus Pocock, 1890, and Uroplectes Peters, 1861. The following scheme of relationships is retrieved among the species of Pseudolychas: (P. ochraceus (P. pegleri + P. transvaalicus)).