Archive for the ‘Recent News’ Category


Abstract:

Arachnids are an important group of arthropods. They are: diverse and abundant; a major constituent of many terrestrial ecosystems; and possess a deep and extensive fossil record. In recent years a number of exceptionally preserved arachnid fossils have been investigated using tomography and associated techniques, providing valuable insights into their morphology. Here we use X-ray microtomography to reconstruct members of two extinct arachnid orders. In the Haptopoda, we demonstrate the presence of ‘clasp-knife’ chelicerae, and our novel redescription of a member of the Phalangiotarbida highlights leg details, but fails to resolve chelicerae in the group due to their small size. As a result of these reconstructions, tomographic studies of three-dimensionally preserved fossils now exist for three of the four extinct orders, and for fossil representatives of several extant ones. Such studies constitute a valuable source of high fidelity data for constructing phylogenies. To illustrate this, here we present a cladistic analysis of the chelicerates to accompany these reconstructions. This is based on a previously published matrix, expanded to include fossil taxa and relevant characters, and allows us to: cladistically place the extinct arachnid orders; explicitly test some earlier hypotheses from the literature; and demonstrate that the addition of fossils to phylogenetic analyses can have broad implications. Phylogenies based on chelicerate morphology—in contrast to molecular studies—have achieved elements of consensus in recent years. Our work suggests that these results are not robust to the addition of novel characters or fossil taxa. Hypotheses surrounding chelicerate phylogeny remain in a state of flux.

fig-1-1x

Link: https://peerj.com/articles/641/#supp-1

Koloti genus

Abstract:

The monophyly and phylogenetic position of Diplocentrus Peters, 1861, has remained ambiguous since the first published phylogenetic analysis of diplocentrid relationships, in which it was rendered paraphyletic by the placement of exemplar species from two other diplocentrid genera, Bioculus Stahnke, 1968, and Didymocentrus Kraepelin, 1905. The discovery of two diplocentrids with neobothriotaxic pedipalps, Diplocentrus magnus Beutelspacher and López-Forment, 1991, and Diplocentrus poncei Francke and Quijano-Ravell, 2009, from the central Mexican states of Guerrero and Michoacán, respectively, raised further questions about the limits of Diplocentrus. A recent phylogenetic analysis of 29 species of Diplocentrus and five exemplar species of the most closely related genera, based on 95 morphological characters and 4202 aligned nucleotides from DNA sequences of five markers in the nuclear and mitochondrial genomes, recovered the monophyly of Diplocentrus, excepting two neobothriotaxic species from central Mexico, justifying their removal from Diplocentrus. In the present contribution, Kolotl, n. gen. is created to accommodate the two species, Kolotl magnus (Beutelspacher and López-Forment, 1991), n. comb., and Kolotl poncei (Francke and Quijano-Ravell, 2009), n. comb., and both are redescribed.
Picture from the Scorpion Files Blog site.
American Museum of Natural History at the Digital Library.
URL @ http://digitallibrary.amnh.org/dspace/handle/2246/5465

syntropinae2

Abstract

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 following taxa are demonstrated to be para- or polyphyletic: Smeringurinae; Syntropinae; Vaejovinae; Stahnkeini; Syntropini; Syntropina; Thorelliina; Hoffmannius; Kochius; and Thorellius. The spinose (hooked or toothed) margin of the distal barb of the sclerotized hemi-mating plug is demonstrated to be a unique, unambiguous synapomorphy for Syntropinae, uniting taxa previously assigned to different subfamilies. Results of the analysis demonstrate a novel phylogenetic relationship for the subfamily, comprising six major clades and 11 genera, justify the establishment of six new genera, and they offer new insights about the systematics and historical biogeography of the subfamily, and the information content of morphological character systems.

Direct Link at http://onlinelibrary.wiley.com/doi/10.1111/cla.12091/abstract.

Thanks to the Scorpion Files posting the news.  Its been a long time coming to see the results from the Scorpion Lab at AMNH.

Summary
A new scorpion species, Vaejovis grayae sp. nov. is described and placed in the “vorhiesi” group of the genus Vaejovis. This small brown species is found near Yarnell, Arizona, USA. It appears most similar to V. trinityae Ayrey and V. crumpi Ayrey et Soleglad. It can be distinguished from the other members of the “vorhiesi” group by aunique combination of non-overlapping morphological characters and multilocus DNA data (Bryson et al., 2013). The pedipalp fixed finger has 6 ID denticles and the movable finger has 7, like most other northern Arizona “vorhiesi” group species. Another characteristic of this species is its unique Arizona chaparral habitat.

grayae

Published at Euscorpius Online Journal:  Occasional papers in scorpiology

PDF:  http://www.science.marshall.edu/fet/euscorpius/p2014_188.pdf

See more with Rich’s web site at AZScorpion.com

Abstract

A new species of the genus Diplocentrus Peters, 1861 is described, based on several specimens collected in the Mexican state of Oaxaca. It is characterized by a high telotarsal spiniform setae count (4-5/5:5/6:6/6:6/6-7), and the pectinal tooth counts of 12–15, mode = 13 (male) or 11–13, mode = 12 (female). With the description of this species, the diversity of the genus is increased to 51 species in Mexico.

Introduction

The genus Diplocentrus Peters, 1861 comprises nearly 60 species, 51 of them are distributed in Mexico, is the most diverse genus in the family Diplocentridae Karsch, 1880 (Santibáñez-López et al. 2013a). The Mexican species were divided in two groups by Hoffmann (1931), based on size and coloration. Francke (1977) redefined the groups in a key to identification of the Diplocentrus species occurring in the Mexican state of Oaxaca, based on cheliceral and pedipalp femur ratios, and renamed the whitei group to mexicanus group because it included type species (Diplocentrus mexicanus Peters, 1861). Nevertheless, Francke (1978) realized that the distinction of both groups was problematic because the diagnostic characters of the pedipalp femur were also used to separate other genera in the family. Recently, Santibáñez-López et al. (2013a) presented an operational diagnosis for the keyserlingii group; but did not assume that it was monophyletic, pending further investigation of Diplocentrus phylogeny. Fifteen species are reported for the Mexican state of Oaxaca, nine of them belong to the keyserlingii group, and six to the mexicanus group. In the present contribution, Diplocentrus franckei, sp. n. from the mexicanus group is described from Oaxaca, Mexico; it is compared to its most morphological similar species.

Citation: Santibáñez-López CA (2014) A new species of the genus Diplocentrus Peters, 1861 (Scorpiones, Diplocentridae) from Oaxaca, Mexico. ZooKeys 412: 103–116

zookeys-412-103-g006zookeys-412-103-g003zookeys-412-103-g005

06 May, 2014

Background

Survival in microrefugia represents an important paradigm in phylogeography for explaining rapid postglacial re-colonization by species in temperate regions. Microrefugia may allow populations to persist in areas where the climatic conditions on the surface have become unfavourable. Caves generally contain stable microclimates and may represent microrefugia for species capable of exploiting both cave and surface habitats (troglophiles). We examine the phylogeography of the troglophilic North American vaejovid scorpion Pseudouroctonus reddelli using 1,993 base pairs of mitochondrial and nuclear DNA sequence data generated from 12 populations. We use (i) descriptive measures of genetic diversity and population genetics statistics, (ii) reconstructions of phylogeographical structure, spatial diffusion during diversification, and population sizes through time, and (iii) species distribution modelling to test predictions of the hypothesis that caves serve as microrefugia. We compare phylogeographical patterns in P. reddelli with other troglophilic species across the Edwards Plateau karst region of Texas.

Results

Results revealed high haplotype and nucleotide diversity and substantial phylogeographical structure, probably generated during the Pleistocene. Spatial diffusion occurred along the southern edge of the Edwards Plateau from multiple refugia along the Balcones Escarpment. There was little evidence for population and geographical expansion. Species distribution models predicted substantial reductions in suitable epigean habitat for P. reddelli at the Last Glacial Maximum (LGM).

Conclusions

High genetic diversity, strong phylogeographical structure, diffusion from multiple refugia, and unfavourable climatic conditions at the LGM collectively support the hypothesis that caves served as microrefugia for P. reddelli. Similar patterns of genetic structure in P. reddelli and other troglophilic species across the Edwards Plateau karst region of Texas suggest that caves serving as microrefugia are important for the formation, maintenance, and future survival of troglophilic species in temperate karst regions.

Keywords:

Last Glacial Maximum; Refugia; Species distribution model; Scorpiones; Vaejovidae

URL:  http://www.biomedcentral.com/1471-2148/14/9

Add in URL http://phylobiogeography.wordpress.com/

 

Genus Kovarikia, gen. nov. (Scorpiones: Vaejovidae) is described from southern California, USA. The genus is composed of three species previously placed in Pseudouroctonus: Kovarikia williamsi (Gertsch et Soleglad, 1972),comb. nov. (type species), K. bogerti (Gertsch et Soleglad, 1972), comb. nov., and K. angelena (Gertsch et Soleglad, 1972), comb. nov. Major diagnostic characters of Kovarikia are its unique neobothriotaxy found on the ventral surface of the pedipalp chelae, the occurrence of a secondary lamellar hook on the hemispermatophore, a crescent-shaped mating plug barb, the presence of a secondary exteromedian (EMc) carina on the pedipalp patella,and a swollen telson vesicle with anterior vesicular ridges. kovarikiaURL link:  http://www.science.marshall.edu/fet/euscorpius/p2014_185.pdf

Random pictures from 2010 in Amarillo Texas:

T hawk 2 T hawk 1Peps

 

Blog title update:  Expanding  into news with general arachnids relevant to North America all in one place.  Mexico and the western states in the U.S. presents various transitions zones and micro habitats and is thus unique in arachnid taxa.

Hope you enjoy the site for educational and regional informations !

Sincerely,

Chad Lee B.Sc. 1995.

Biology and Natural Resource Management.  Texas Certified Applicator

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coalcomanSummary:

Vaejovis coalcoman sp. n. from Sierra de Coalcomán, in the northwestern part of the state of Michoacán, Mexico, is described. It belongs to the “mexicanus” group and it is compared with related species from the states of Jalisco and Guanajuato. A map with the known distribution of the related taxa is provided.

URL and PDF:  http://www.journals.unam.mx/index.php/bio/article/view/37437