Morphological phylogeny of cobweb spiders and their relatives (Araneae, Araneoidea, Theridiidae)

This paper offers the first cladistic analysis of a wide selection of theridiid genera based on morphological data. The analysis treats 53 theridiid taxa representing 32 genera (Achaearanea, Anelosimus, Ameridion, Argyrodes, Ariamnes, Carniella, Cerocida, Chrysso, Coleosoma, Dipoena, Emertonella, Enoplognatha, Episinus, Euryopis, Faiditus, Kochiura, Latrodectus, Neospintharus, Nesticodes, Pholcomma, Phoroncidia, Rhomphaea, Robertus, Selkirkiella, Spintharus, Steatoda, Stemmops, Theridion, Theridula, Thymoites, Thwaitesia, Tidarren) and eight outgroup taxa representing the families Nesticidae (Eidmanella and Nesticus), Synotaxidae (Synotaxus, two species), Pimoidae (Pimoa), Linyphiidae (Linyphia), Tetragnathidae (Tetragnatha) and Araneidae (Argiope). The parsimony analysis of 242 morphological and behavioural characters found a single, most parsimonious tree. The monophyly of theridiids and their sister relationship with nesticids is strongly supported. The recent resurrection of Ariamnes and Rhomphaea from Argyrodes made the latter paraphyletic. However, Ariamnes and Rhomphaea are characterized by an array of characters, and Argyrodes still contains dramatically distinct clades for which names are available: Faiditus (removed from synonymy ? RS) and Neospintharus (RS). These revalidations provide a classification with greater information content and utility. These three genera, along with Ariamnes, Rhomphaea and Spheropistha, comprise the subfamily Argyrodinae. The monophyly and composition of the subfamilies Hadrotarsinae, Spintharinae, Pholcommatinae, Latrodectinae and Theridiinae are discussed. Theridion is paraphyletic and in need of revision. Anelosimus as currently circumscribed is paraphyletic, a problem resolved by revalidating Selkirkiella (RS) and Kochiura (RS). Numerous new combinations are established. The results suggest the monophyletic origin of both kleptoparasitism and araneophagy in the lineage leading to Argyrodinae, negating hypotheses that either arose from the other. Sociality evolved multiple times within the family, accounting for as much as one fourth of the origins of social behaviour among all spiders. No losses of sociality are implied. The hypothesis of maternal care as the pathway to sociality receives support. Evolution of theridiid webs is complex, with multiple modifications and loss of the basic theridiid cobweb. © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society, 2004, 141 , 447–626.     

Comb-footed spiders(Araneae:Theridiidae) in the tropical rainforest of Xishuangbanna,Southwest China

Xishuangbanna,with its typical tropical rainforest,is one of China's biodiversity hotspots.Through several years of extensive survey work on the spiders in rainforest and adjacent habitats,32 genera and 101 species,including 33 new species,of the family Theridiidae were collected.Four genera,Allothymoites Ono,2007,Nojimaia Yoshida,2009,Tekellina Levi,1957 and Yunohamella Yoshida,2007,are newly recorded from China.The 33new species are diagnosed,described and illustrated.Type specimens are deposited in the Institute of Zoology,Chinese Academy of Sciences in Beijing(IZCAS).     

Nanoa, an enigmatic new genus of pimoid spiders from western North America (Pimoidae, Araneae)

The spider genus Nanoa gen. nov. (Araneae, Pimoidae) is described to place Nanoa enana , a new species of pimoids from Western North America. Parsimony analysis of morphological characters provides support for the monophyly of Pimoa plus Nanoa and corroborates the monophyly of Pimoidae and of the clade Linyphiidae plus Pimoidae. © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 145 , 249–262.     

A revision of the assassin spiders of the Eriauchenius gracilicollis group, a clade of spiders endemic to Madagascar (Araneae: Archaeidae)

An endemic group of Malagasy spiders (Araneae: Archaeidae: Eriauchenius ) called the gracilicollis group is revised. The monophyly and phylogenetic relationships of the gracilicollis group are tested based on morphological characters. Archaeid spiders of Madagascar have evolved varying degrees of elongation in the cephalic area. Historically, it was believed that the extremely elongated cephalic area had evolved only once. These morphological data support the monophyly of the gracilicollis group and suggest that the elongated cephalic area has evolved more than once. All 14 species from the gracilicollis group are described and keyed, of which nine are new species: Eriauchenius ambre sp. nov. , Eriauchenius anabohazo sp. nov. , Eriauchenius borimontsina sp. nov. , Eriauchenius griswoldi sp. nov. , Eriauchenius halambohitra sp. nov. , Eriauchenius lavatenda sp. nov. , Eriauchenius namoroka sp. nov. , Eriauchenius spiceri sp. nov. and Eriauchenius voronakely sp. nov . The morphology of the gracilicollis group is examined in detail and figures of the male and female genitalia are presented. The distributions of the gracilicollis group species are presented and discussed and higher species group relationships within the Archaeidae are discussed.  © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 152 , 255–296.     

An extraordinary new genus of spiders from Western Australia with an expanded hypothesis on the phylogeny of Tetragnathidae (Araneae)

We describe Pinkfloydia Hormiga & Dimitrov gen. nov. , a new genus of tetragnathid spiders from Western Australia and study its phylogenetic placement. The taxon sampling from our previous cladistic studies was expanded, with the inclusion of representatives of additional tetragnathid genera and outgroup taxa. Sequences from six genetic markers, 12S, 16S, 18S, 28S, cytochrome c oxidase subunit 1, and histone 3, along with morphological and behavioural data were used to infer tetragnathid relationships. These data were analysed using parsimony (under both static homology and dynamic optimization) and Bayesian methods. Our results indicate that Pinkfloydia belongs to the ‘Nanometa’ clade. We also propose a revised set of synapomorphies to define this lineage. Based on the new evidence presented here we propose a revised hypothesis for the intrafamilial relationships of Tetragnathidae and show that Mimetidae is most likely the sister group of Tetragnathidae. The single species in this genus so far, Pinkfloydia harveii Dimitrov& Hormiga sp. nov. , is described in detail and its web architecture documented and illustrated. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 161 , 735–768.     

Functional morphology of female goblin spider genitalia (Arachnida: Araneae: Oonopidae) with notes on fertilization in spiders

The genital structures of most spiders are poorly investigated in respect of their functional morphology because the traditional taxonomic practice is to inspect slide-mounted genitalia only. The present study describes the female genitalia of three members belonging to the megadiverse haplogyne spider family Oonopidae by means of histological serial sections, scanning electron microscopy, and X-ray ultramicroscopy. The female genitalia of Neoxyphinus ogloblini, Dysderina sp., and Heteroonops spinimanus are complex and might have evolved under sexual selection by cryptic female choice. However, there is no direct evidence for cryptic female choice in these species based on the results of the present study. In N. ogloblini and Dysderina sp., spermatozoa and secretion are stored in a large receptaculum. Highly elongated gland cells filled with secretory vesicles extend over the receptaculum of N. ogloblini. In addition, sperm are present in the uterus internus of female N. ogloblini and Dysderina sp. The location of fertilization is still unknown for most spiders. One female of Dysderina sp. had sperm in the uterus and ovary strongly suggesting that fertilization in this species takes place in the ovary. An anterior sclerite with attached muscles should serve females to lock the uterus externus during copulation as suggested for other oonopids. The male palp of N. ogloblini shows a simple embolus whereas the embolus of Dysderina sp. is more complicated and accompanied by a cork-screw-shaped conductor. Females of H. spinimanus have an anterior sclerite in which thread-like gland ducts lead. The chitinized posterior diverticulum shows peculiar papillae in its anterior wall. The exact location of sperm storage in H. spinimanus remains unknown since spermatozoa were not present in the anterior sclerite and the posterior diverticulum. The anterior sclerite might be used to lock the uterus externus similar to N. ogloblini and Dysderina sp. H. spinimanus was previously suggested to be parthenogenetic and a male has only been recently associated with this species. The male was not investigated for this study.     

The phylogeny of the social Anelosimus spiders (Araneae: Theridiidae) inferred from six molecular loci and morphology

We use fragments of three nuclear genes (Histone 3, 18SrDNA, and 28SrDNA) and three mitochondrial genes (16SrDNA, ND1, and COI) totalling approximately 4.5kb, in addition to morphological data, to estimate the phylogenetic relationships among Anelosimus spiders, well known for their sociality. The analysis includes 67 individuals representing 23 of the 53 currently recognized Anelosimus species and all species groups previously recognized by morphological evidence. We analyse the data using Bayesian, maximum likelihood, and parsimony methods, considering the genes individually as well as combined (mitochondrial, nuclear, and both combined) in addition to a 'total evidence' analysis including morphology. Most of the data partitions are congruent in agreeing on several fundamental aspects of the phylogeny, and the combined molecular data yield a tree broadly similar to an existing morphological hypothesis. We argue that such congruence among data partitions is an important indicator of support that may go undetected by standard robustness estimators. Our results strongly support Anelosimus monophyly, and the monophyly of the recently revised American 'eximius lineage', although slightly altered by excluding A. pacificus. There was consistent support for the scattering of American Anelosimus species in three clades suggesting intercontinental dispersal. Several recently described species are reconstructed as monophyletic, supporting taxonomic decisions based on morphology and behaviour in this taxonomically difficult group. Corroborating previous results from morphology, the molecular data suggest that social species are scattered across the genus and thus that sociality has evolved multiple times, a significant finding for exploring the causes and consequences of social evolution in this group of organisms.     

Weintrauboa, a new genus of pimoid spiders from Japan and adjacent islands, with comments on the monophyly and diagnosis of the family Pimoidae and the genus Pimoa (Araneoidea, Araneae)

The spider genus Weintrauboa new genus (Araneae, Pimoidae) is described to place two species of pimoids from Japan and adjacent islands that were formerly classified in the linyphiid genus Labulla . Weintrauboa contortipes (Karsch) new comb., the type species, and W. chikunii (Oi) new comb. are redescribed. Parsimony analysis of morphological characters provides robust support for the monophyly of the genus Weintrauboa and corroborates the monophyly of Pimoa , Pimoidae, and the clade Linyphiidae plus Pimoidae. New diagnoses for Pimoa and Pimoidae are provided.  © 2003 The Linnean Society of London, Zoological Journal of the Linnean Society , 2003, 139 , 261–281     

Cladistics and the comparative morphology of linyphiid spiders and their relatives (Araneae, Araneoidea, Linyphiidae)

This paper provides the first quantitative cladistic analysis of linyphiid morphology. Classical and novel homology hypotheses for a variety of character systems (male and female genitalia, somatic morphology, spinneret silk spigot morphology, etc.) are critically examined and studied within a phylogenetic context. Critical characters have been illustrated. A sample of linyphiid taxa (nine genera in four subfamilies), five species of Pimoa (Pimoidae), and two other araneoid families (Tetragnathidae and Araneidae, represented by Tetragnatha and Zygiella , respectively) were used to study the implications of the phylogeny of Pimoidae for the systematics of linyphiids. The phylogenetic relationships of these 16 exemplar taxa, as coded for the 47 characters studied, were analysed using numerical cladistic methods. In the preferred cladogram Pimoidae and Linyphiidae are sister groups, Stemonyphantinae are sister group to the remaining linyphiids, and Mynogleninae are sister group to the clade composed of Erigoninae plus Linyphiinae. These results agree with the relationships recently proposed by Wunderlich, except by finding erigonines as the sister group to linyphiines rather than to mynoglenines.     

Acutipetala, gen. nov., a new genus of funnel-web spiders from northern Thailand (Araneae, Agelenidae)

A new funnel-web spider genus, Acutipetala, gen. nov., is erected to accommodate two new agelenid species known to occur in evergreen forests of northern Thailand: Acutipetala octoginta, sp. nov. (type species,male symbolfemale symbol) and A. donglini, sp. nov. (male symbol). The genus is established on the basis of the distinctive appearance of the genital structures, in which the median apophysis of the male palp is petal-shaped, sharply pointed, and strongly sclerotized, and the truncate embolus is short, originates subapically, and is provided with a hook-shaped apical portion.     

Revision and cladistic analysis of Isoctenus and description of a new neotropical genus (Araneae,Ctenidae, Cteninae)

A cladistic analysis was applied to test the monophyly of the genus Isoctenus. The data matrix comprised 28 taxa scored for 53 morphological and two behavioural characters. The analysis resulted in two equally parsimonious trees of 89 steps. The strict consensus was used to discuss the relationships of Isoctenus and related Cteninae genera. Ctenopsis Schmidt is synonymized with Isoctenus. Isoctenus foliifer Bertkau, I. strandi Mello‐Leitão, I. eupalaestrus Mello‐Leitão, I. janeirus (Walckenaer), I. coxalis (Pickard‐Cambridge), I. corymbus Polotow, Brescovit & Pellegatti‐Franco and I. malabaris Polotow, Brescovit & Ott are maintained in Isoctenus. Four species currently included in Ctenus are transferred to Isoctenus: I. griseolus (Mello‐Leitão) comb. nov., I. taperae (Mello‐Leitão) comb. nov., I. herteli (Mello‐Leitão) comb. nov. and I. minusculus (Keyserling) comb. nov. The following specific names are synonymized: Ctenus sanguineus Walckenaer, C. semiornatus Mello‐Leitão and Ctenopsis stellata Schmidt with Isoctenus janeirus (Walckenaer), Ctenus mourei Mello‐Leitão with Isoctenus herteli (Mello‐Leitão) and Ctenus pauper Mello‐Leitão with Isoctenus strandi Mello‐Leitão. Isoctenus sigma Schenkel, described from French Guiana, is transferred to Ctenus. Four species are newly described: Isoctenus areia sp. nov. from Paraíba, Brazil, I. charada sp. nov. and I. segredo sp. nov. from Paraná, Brazil, and I. ordinario sp. nov. from south and south‐eastern Brazil and north‐eastern Argentina. Isoctenus latevittatus Caporiacco is considered species inquirenda. Parabatinga gen. nov. is proposed to include Ctenus brevipes Keyserling. The following synonymies are established: Ctenus taeniatus Keyserling, C. tatarandensis Tullgren, C. anisitsi Strand, C. atrivulvus Strand, C. mentor Strand, C. brevipes brevilabris Strand, Isoctenus masculus Mello‐Leitão and Ctenus birabeni Mello‐Leitão with Parabatinga brevipes (Keyserling) comb. nov. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 583–614.     

Deep phylogenetic divergence between Scolytoplatypus and Remansus,a new genus of Scolytoplatypodini from Madagascar (Coleoptera,Curculionidae, Scolytinae)

Scolytoplatypodini Blandford is a monotypic tribe of ambrosia beetles found in Asia, Madagascar and Africa. Only three species are currently known from Madagascar and four additional species are here described as new to science. Phylogenetic analyses of morphological and molecular data revealed that four of the seven endemic species are deeply separated from all other species by genetic and distinct morphological characters and therefore placed in a new genus Remansus Jordal. The split between this ancient lineage and Scolytoplatypus Schaufuss was estimated to approximate Palaeocene age (63 Ma), extending the minimum age of ambrosia feeding for this tribe to the beginning of the Palaeocene‒Eocene thermal maximum (PETM). In addition to the ancient origin of Remansus in Madagascar during the Palaeocene, a second origin occurred in Scolytoplatypus no more than 13 Ma. A geographical origin of the latter in South-Eastern Africa was unequivocally inferred from the phylogenies.     

From a comb to a tree: phylogenetic relationships of the comb-footed spiders (Araneae, Theridiidae) inferred from nuclear and mitochondrial genes

The family Theridiidae is one of the most diverse assemblages of spiders, from both a morphological and ecological point of view. The family includes some of the very few cases of sociality reported in spiders, in addition to bizarre foraging behaviors such as kleptoparasitism and araneophagy, and highly diverse web architecture. Theridiids are one of the seven largest families in the Araneae, with about 2200 species described. However, this species diversity is currently grouped in half the number of genera described for other spider families of similar species richness. Recent cladistic analyses of morphological data have provided an undeniable advance in identifying the closest relatives of the theridiids as well as establishing the family's monophyly. Nevertheless, the comb-footed spiders remain an assemblage of poorly defined genera, among which hypothesized relationships have yet to be examined thoroughly. Providing a robust cladistic structure for the Theridiidae is an essential step towards the clarification of the taxonomy of the group and the interpretation of the evolution of the diverse traits found in the family. Here we present results of a molecular phylogenetic analysis of a broad taxonomic sample of the family (40 taxa in 33 of the 79 currently recognized genera) and representatives of nine additional araneoid families, using approximately 2.5kb corresponding to fragments of three nuclear genes (Histone 3, 18SrDNA, and 28SrDNA) and two mitochondrial genes (16SrDNA and CoI). Several methods for incorporating indel information into the phylogenetic analysis are explored, and partition support for the different clades and sensitivity of the results to different assumptions of the analysis are examined as well. Our results marginally support theridiid monophyly, although the phylogenetic structure of the outgroup is unstable and largely contradicts current phylogenetic hypotheses based on morphological data. Several groups of theridiids receive strong support in most of the analyses: latrodectines, argyrodines, hadrotarsines, a revised version of spintharines and two clades including all theridiids without trace of a colulus and those without colular setae. However, the interrelationships of these clades are sensitive to data perturbations and changes in the analysis assumptions.     

Stentorceps, a remarkable new genus of eucoilid (Hymenoptera) from Africa

Abstract. Stentorceps tubicen , a new genus and species of Eucoilidae from East Africa, is described and illustrated. The genus is characterized by the possession of large protrusions on the face, features previously unknown in the family. The genus is compared with other eucoilids and its systematic position is discussed.     

The female genital morphology of the orb weaving spider genus Agriognatha (Araneae, Tetragnathidae)

The female genital morphology of the spiders in the araneoid genus Agriognatha (Tetragnathidae) is described and illustrated. The female genitalia of Agriognatha is characterized by a strong reduction of the sperm storage organs (spermathecae) and by the presence of a specialized distal compartment of the median membranous chamber that functions as a sperm storage organ (the posterior sac). The genital morphology of Agriognatha species is unique among Tetragnathidae and it provides robust synapomorphic evidence for the monophyly of genus. We discuss the phylogenetic implications of these new findings for the placement and monophyly of Agriognatha and for the monophyly of Tetragnathinae.     

The lace web spiders (Araneae,Phyxelididae) of Madagascar: phylogeny,biogeography and taxonomy

We briefly review the potential history of Madagascar as either a Darwinian or a Wallacean island, summarize the phylogenetic evidence regarding the biogeography of Madagascar spiders, examine the dispersal history of the Madagascar Phyxelididae, and monograph the family in Madagascar. Molecular phylogenetic analyses for 32 Malagasy phyxelidid exemplars, nine confamilial outgroup taxa, and seven other more distant outgroups are performed for three nuclear markers and one mitochondrial genetic marker (28S, 18S, H3 and COI) utilizing Bayesian, maximum‐likelihood and parsimony methods. These analyses suggest that there are 14 species of Phyxelididae that may be recognized from Madagascar, that these may be divided into three genera, and that the Malagasy phyxelidids form a monophyletic group, probably resulting from a single invasion of the island by an ancestor from Africa. Two new genera, ten new species, and two new combinations are proposed: Manampoka atsimo gen. nov., sp. nov. ; Rahavavy gen. nov. , including R. ida sp. nov. and R. fanivelona (Griswold, 1990) comb. nov. and R. malagasyana (Griswold, 1990) comb. nov. ; and Ambohima andrefana sp. nov. , A. antsinanana sp. nov. , A. avaratra sp. nov. , A. maizina sp. nov. , A. ranohira sp. nov. , A. vato sp. nov. , A. zandry sp. nov. and A. zoky sp. nov. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 164 , 728–810.