Archive for February, 2016


spider phylogenomics

Abstract

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. To further resolve spider evolutionary relationships we have assembled a transcriptome-based data set comprising 70 ingroup spider taxa. Using maximum likelihood and shortcut coalescence-based approaches, we analyze eight data sets, the largest of which contains 3,398 gene regions and 696,652 amino acid sites forming the largest phylogenomic analysis of spider relationships produced to date. Contrary to long held beliefs that the orb web is the crowning achievement of spider evolution, ancestral state reconstructions of web type support a phylogenetically ancient origin of the orb web, and diversification analyses show that the mostly ground-dwelling, web-less RTA clade diversified faster than orb weavers. Consistent with molecular dating estimates we report herein, this may reflect a major increase in biomass of non-flying insects during the Cretaceous Terrestrial Revolution 125–90 million years ago favoring diversification of spiders that feed on cursorial rather than flying prey. Our results also have major implications for our understanding of spider systematics. Phylogenomic analyses corroborate several well-accepted high level groupings: Opisthothele, Mygalomorphae, Atypoidina, Avicularoidea, Theraphosoidina, Araneomorphae, Entelegynae, Araneoidea, the RTA clade, Dionycha and the Lycosoidea. Alternatively, our results challenge the monophyly of Eresoidea, Orbiculariae, and Deinopoidea. The composition of the major paleocribellate and neocribellate clades, the basal divisions of Araneomorphae, appear to be falsified. Traditional Haplogynae is in need of revision, as our findings appear to support the newly conceived concept of Synspermiata. The sister pairing of filistatids with hypochilids implies that some peculiar features of each family may in fact be synapomorphic for the pair. Leptonetids now are seen as a possible sister group to the Entelegynae, illustrating possible intermediates in the evolution of the more complex entelegyne genitalic condition, spinning organs and respiratory organs.

URL at https://peerj.com/articles/1719/

Great Article not relevant to North America but wonderful to the Americas in general.

 

Abstract

Eight new species of Charinus Simon, 1892 are described for the Brazilian Amazon, from the states of Pará (C. bichuetteae sp. n., C. bonaldoi sp. n., C. carajas sp. n., C. ferreus sp. n., C.guto sp. n. and C. orientalis sp. n.) and Amazonas (Charinus brescoviti sp. n. and C. ricardoi sp. n.). All new species can be differentiated from the other species of the genus by the number of pseudo-articles in basitibia IV, the presence/absence of median eyes, and the shape of the female gonopod. Brazil now becomes the country with the largest diversity of Amblypygi in the world, with 25 known species. Half of the new species described here have a high degree of endangerment: C. bichuetteae sp. n. is threatened by the flood caused by the hydroelectric dam of Belo Monte, and C. carajas sp. n., C. ferreus sp. n. and C. orientalis sp. n. are endangered by the iron mining in Carajás municipality and surroundings. The Charinus species here described are endemic to the Amazon Region, so in order to assure their preservation, it is strongly recommended a special care with their habitats (type localities) which are facing increasing rates of destruction and deforestation.

journal.pone.0148277.g001

PLOS ONE:  URL @ http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0148277

johnny-cash-tarantula-2 (1)

Abstract

This systematic study documents the taxonomy, diversity, and distribution of the tarantula spider genusAphonopelma Pocock, 1901 within the United States. By employing phylogenomic, morphological, and geospatial data, we evaluated all 55 nominal species in the United States to examine the evolutionary history of Aphonopelma and the group’s taxonomy by implementing an integrative approach to species delimitation. Based on our analyses, we now recognize only 29 distinct species in the United States. We propose 33 new synonymies (A. apacheum, A. minchi, A. rothi, A. schmidti, A. stahnkei = A. chalcodes; A.arnoldi = A. armada; A. behlei, A. vogelae = A. marxi; A. breenei = A. anax; A. chambersi, A. clarum, A.cryptethum, A. sandersoni, A. sullivani = A. eutylenum; A. clarki, A. coloradanum, A. echinum, A. gurleyi, A.harlingenum, A. odelli, A. waconum, A. wichitanum = A. hentzi; A. heterops = A. moderatum; A. jungi, A.punzoi = A. vorhiesi; A. brunnius, A. chamberlini, A. iviei, A. lithodomum, A. smithi, A. zionis = A. iodius; A.phanum, A. reversum = A. steindachneri), 14 new species (A. atomicumsp. n., A. catalinasp. n., A.chiricahuasp. n., A. icenogleisp. n., A. johnnycashisp. n., A. maderasp. n., A. marekisp. n., A. moellendorfisp. n., A. parvumsp. n., A. peloncillosp. n., A. prenticeisp. n., A. saguarosp. n., A. superstitionensesp. n., and A. xwalxwalsp. n.), and seven nomina dubia (A. baergi, A. cratium, A. hollyi, A. mordax, A. radinum, A.rusticum, A. texense). Our proposed species tree based on Anchored Enrichment data delimits five major lineages: a monotypic group confined to California, a western group, an eastern group, a group primarily distributed in high-elevation areas, and a group that comprises several miniaturized species. Multiple species are distributed throughout two biodiversity hotspots in the United States (i.e., California Floristic Province and Madrean Pine-Oak Woodlands). Keys are provided for identification of both males and females. By conducting the most comprehensive sampling of a single theraphosid genus to date, this research significantly broadens the scope of prior molecular and morphological investigations, finally bringing a modern understanding of species delimitation in this dynamic and charismatic group of spiders.

Awesome …

URL http://zookeys.pensoft.net/articles.php?id=6264

See also the National Geographic article at http://news.nationalgeographic.com/2016/02/160204-animals-spiders-tarantulas-science-nation/

LiveScience review at http://www.livescience.com/53616-tarantula-named-for-johnny-cash.html

cryptomaster-daddylonglegs

Scientists have unearthed a monstrous new arachnid lurking in the woods of southwest Oregon — and it’s a beast.

The new daddy longlegs species, dubbed Cryptomaster behemoth,towers over other creatures of its kind. And like its cousin, the equally elusive Cryptomaster leviathan, the new species is incredibly difficult to find, because it hides out beneath the logs and leafy debris that blanket the forest floor.

The Cryptomaster leviathan was discovered in 1969 at one location in the coastal town of Gold Beach, Oregon. The mysterious creature belonged to one of the most diverse suborders, called Laniatores, which contains at least 4,100 species. (Daddy longlegs belong to the arachnid order commonly known as harvestmen, so-called because they often emerge during the fall months during the harvest.