Search

Petra sierwaldae, n. gen., n. sp. is described from males and females collected at four localities in Kootenai County, Idaho, USA. The new genus is defined by its unique gonopod and ninth leg anatomy, a notched collum and single ommatidium on each side of the head, and lacking third coxal flasks as well as having modified fifth coxae.

Higher-level classifications often must account for monotypic taxa representing depauperate evolutionary lineages and lacking synapomorphies of their better-known, well-defined sister clades. In a ranked (Linnean) or unranked (phylogenetic) classification system, discovering such a depauperate taxon does not necessarily invalidate the rank classification of sister clades. Named higher taxa must be monophyletic to be phylogenetically valid. Ranked taxa above the species level should also maximize information content, diagnosability, and utility (e.g., in biodiversity conservation). In spider classification, families are the highest rank that is systematically catalogued, and incertae sedis is not allowed. Consequently, it is important that family-level taxa be well defined and informative. We revisit the classification problem of Orbipurae, an unranked suprafamilial clade containing the spider families Nephilidae, Phonognathidae, and Araneidae sensu stricto. We argue that, to maximize diagnosability, information content, conservation utility, and practical taxonomic considerations, this “splitting” scheme is superior to its recently proposed alternative, which lumps these families together as Araneidae sensu lato. We propose to redefine Araneidae and recognize a monogeneric spider family, Paraplectanoididae fam. nov. to accommodate the depauperate lineage Paraplectanoides. We present new subgenomic data to stabilize Orbipurae topology which also supports our proposed family-level classification. Our example from spiders demonstrates why classifications must be able to accommodate depauperate evolutionary lineages, for example, Paraplectanoides. Finally, although clade age should not be a criterion to determine rank, other things being equal, comparable ages of similarly ranked taxa do benefit comparative biology. [Classification, family rank, phylogenomics, systematics, monophyly, spider phylogeny.]

Spiders are notoriously solitary and cannibalistic, with instances of colonial or social lifestyles in only about 50-60, or ~0.1% of 50,000 described species. Population analyses indicate that most colonies consist of multiple cohorts formed by close relatives. Territorial social spiders facultatively form colonies by interlinking individual webs, but further cooperation is infrequent, and only among juveniles or (rarely) females. In spiders therefore, aggregations of males outside of the male-male competition context has been unknown. Here, we report on a discovery of a kite spider from Madagascar that exhibits unique colonies. We found colonies of the newly described araneid Isoxya manangonan. sp. formed by up to 41 interconnected, single-cohort adult female webs with up to 38 adult males aggregating on a central, single, nonsticky line. With males resting tightly together, we found no evidence for male-male aggression. Genetic analyses from RAD sequencing suggest that most colonies consist of unrelated individuals. Furthermore, genetic variability of males was somewhat less than that of females. Single cohort colonies made up purely of adults, and peaceful male aggregations, have not previously been observed in spiders. Although direct behavioral observations are preliminary, we speculate based on the available evidence that these colonies may represent a novel and first case of lekking in spiders.

In millipedes, gonopods are male copulatory genitalia derived from walking legs that metamorphose during postembryonic development. The morphology of gonopods is critical for genus and species diagnosis in most taxa. However, the form and function of gonopods vary drastically at the family and ordinal level, making intricate morphological comparison practically impossible. Internal morphology could provide the basis for homologizing morphological elements present in the walking legs and gonopods. Therefore, we used x-ray computed tomography to produce 3D segmentations of Pseudopolydesmus Attems, 1898 (Polydesmida: Polydesmidae) millipedes incorporating two types of morphological elements: skeletal elements and muscles. In addition to imaging the trunk and appendages of an adult male, we imaged the developing gonopod across a series of juvenile male stadia in order to trace the identities of morphological elements. Skeletal elements were homologized, but muscle homologies were limited by the dissimilarity of muscle attachment sites between the walking leg and gonopod. Furthermore, images of juvenile males showed that appendage musculature is totally obliterated once gonopod development begins in the fourth stadium. Due to these limitations, we believe it may be more tractable to homologize gonopod musculature of various millipede taxa to each other than to that of the walking legs. Because distinct genetic developmental networks responsible for walking leg and gonopod patterning have been evolving separately since the common ancestor of gonopod-bearing millipedes (a case of paramorphy), skeletomusculature among gonopods of unrelated millipede taxa is expected to be more similar than that of the gonopod and walking leg within a given millipede lineage.

This study documents a comprehensive taxonomic treatment of the New World Ummidia species. At the onset of this work the genus comprised 27 species and one subspecies with a cosmopolitan distribution that includes North America, South America, Asia, northern Africa, and Europe; of these species the majority of the nominal diversity can be attributed to the New World where 20 species have been previously described. Ummidia oaxacana (Chamberlin, 1925) is considered a nomen dubium; U. tuobita (Chamberlin, 1917) and U. absoluta (Gertsch and Mulaik, 1940) are both considered junior synonyms of U. audouini (Lucas, 1835); the subspecies U. carabivora emarginata (Atkinson, 1886) is considered a junior synonym of U. carabivora (Atkinson, 1886); U. pygmaea (Chamberlin and Ivie, 1945) is considered a junior synonym of U. beatula (Gertsch and Mulaik, 1940); U. celsa (Gertsch and Mulaik, 1940) is considered a junior synonym of U. funerea (Gertsch, 1936); Hebestatis lanthanus (Valerio, 1987) is considered a junior synonym of U. rugosa (Karsch, 1880). Thirty-three new species are described: U. neilgaimani, U. gingoteague, U. rongodwini, U. okefenokee, U. richmond, U. macarthuri, U. colemanae, U. rosillos, U. mercedesburnsae, U. paulacushingae, U. waunekaae, U. gertschi, U. timcotai, U. gabrieli, U. pesiou, U. rodeo, U. huascazaloya, U. anaya, U. cuicatec, U. brandicarlileae, U. riverai, U. frankellerae, U. hondurena, U. yojoa, U. matagalpa, U. carlosviquezi, U. varablanca, U. quepoa, U. cerrohoya, U. quijichacaca, U. tibacuy, U. neblina, U. tunapuna.

Leptonetidae are rarely encountered spiders, usually associated with caves and mesic habitats, and are disjunctly distributed across the Holarctic. Data from ultraconserved elements (UCEs) were used in concatenated and coalescent-based analyses to estimate the phylogenetic history of the family. Our taxon sample included close outgroups, and 90% of described leptonetid genera, with denser sampling in North America and Mediterranean Europe. Two data matrices were assembled and analysed; the first ‘relaxed’ matrix includes the maximum number of loci and the second ‘strict’ matrix is limited to the same set of core orthologs but with flanking introns mostly removed. A molecular dating analysis incorporating fossil and geological calibration points was used to estimate divergence times, and dispersal–extinction–cladogenesis analysis (DEC) was used to infer ancestral distributions. Analysis of both data matrices using maximum likelihood and coalescent-based methods supports the monophyly of Archoleptonetinae and Leptonetinae. However, relationships among Archoleptonetinae, Leptonetinae, and Austrochiloidea are poorly supported and remain unresolved. Archoleptonetinae is elevated to family rank Archoleptonetidae (new rank) and Leptonetidae (new status) is restricted to include only members of the subfamily Leptonetinae; a taxonomic review with morphological diagnoses is provided for both families. Four well supported lineages within Leptonetidae (new status) are recovered: (1) the Calileptoneta group, (2) the Leptoneta group, (3) the Paraleptoneta group, and (4) the Protoleptoneta group. Most genera within Leptonetidae are monophyletic, although Barusia, Cataleptoneta, and Leptoneta include misplaced species and require taxonomic revision. The origin of Archoleptonetidae (new rank), Leptonetidae, and the four main lineages within Leptonetidae date to the Cretaceous. DEC analysis infers the Leptoneta and Paraleptoneta groups to have ancestral distributions restricted to Mediterranean Europe, whereas the Calileptoneta and Protoleptoneta groups include genera with ancestral distributions spanning eastern and western North America, Mediterranean Europe, and east Asia. Based on a combination of biology, estimated divergence times, and inferred ancestral distributions we hypothesise that Leptonetidae was once widespread across the Holarctic and their present distributions are largely the result of vicariance. Given the wide disjunctions between taxa, we broadly interpret the family as a Holarctic relict fauna and hypothesise that they were once part of the Boreotropical forest ecosystem.

Understanding the relative importance of different sources of selection (e.g., the environment, social/sexual selection) on the divergence or convergence of reproductive communication can shed light on the origin, maintenance, or even disappearance of species boundaries. Using a multistep approach, we tested the hypothesis that two presumed sister species of wolf spider with overlapping ranges and microhabitat use, yet differing degrees of sexual dimorphism, have diverged in their reliance on modality‐specific courtship signaling. We predicted that male Schizocosa crassipalpata (no ornamentation) rely predominantly on diet‐dependent vibratory signaling for mating success. In contrast, we predicted that male S. bilineata (black foreleg brushes) rely on diet‐dependent visual signaling. We first tested and corroborated the sister‐species relationship between S. crassipalpata and S. bilineata using phylogenomic scale data. Next, we tested for species‐specific, diet‐dependent vibratory and visual signaling by manipulating subadult diet and subsequently quantifying adult morphology and mature male courtship signals. As predicted, vibratory signal form was diet‐dependent in S. crassipalpata, while visual ornamentation (brush area) was diet‐dependent in S. bilineata. We then compared the species‐specific reliance on vibratory and visual signaling by recording mating across artificially manipulated signaling environments (presence/absence of each modality in a 2 × 2 full factorial design). In accordance with our diet dependence results for S. crassipalpata, the presence of vibratory signaling was important for mating success. In contrast, the light and vibratory environment interacted to influence mating success in S. bilineata, with vibratory signaling being important only in the absence of light. We found no differences in overall activity patterns. Given that these species overlap in much of their range and microhabitat use, we suggest that competition for signaling space may have led to the divergence and differential use of sensory modalities between these sister species., Using phylogenomic scale data, this study first confirms the sister‐species relationship of two wolf spiders—Schizocosa crassipalpata and Schizocosa bilineata—that overlap in range and habitat. Next, using a combination of diet manipulations and laboratory‐based behavioral assays, we demonstrate that the species diverge in the form and function of their courtship signaling. Schizocosa crassipalpata shows diet‐dependent vibratory signals, while visual ornamentation was diet‐dependent in S. bilineata. Coincident with this, vibratory signaling was important for mating success in S. crassipalpata, while there was an interaction between vibratory signaling and visual signaling for S. bilineata. We suggest that competition for signaling space has influenced signaling divergence in these sister species.

Although species delimitation can be highly contentious, the development of reliable methods to accurately ascertain species boundaries is an imperative step in cataloguing and describing Earth's quickly disappearing biodiversity. Spider species delimitation remains largely based on morphological characters; however, many mygalomorph spider populations are morphologically indistinguishable from each other yet have considerable molecular divergence. The focus of our study, the Antrodiaetus unicolor species complex containing two sympatric species, exhibits this pattern of relative morphological stasis with considerable genetic divergence across its distribution. A past study using two molecular markers, COI and 28S, revealed that A. unicolor is paraphyletic with respect to A. microunicolor. To better investigate species boundaries in the complex, we implement the cohesion species concept and use multiple lines of evidence for testing genetic exchangeability and ecological interchangeability. Our integrative approach includes extensively sampling homologous loci across the genome using a RADseq approach (3RAD), assessing population structure across their geographic range using multiple genetic clustering analyses that include structure, principal components analysis and a recently developed unsupervised machine learning approach (Variational Autoencoder). We evaluate ecological similarity by using large-scale ecological data for niche-based distribution modelling. Based on our analyses, we conclude that this complex has at least one additional species as well as confirm species delimitations based on previous less comprehensive approaches. Our study demonstrates the efficacy of genomic-scale data for recognizing cryptic species, suggesting that species delimitation with one data type, whether one mitochondrial gene or morphology, may underestimate true species diversity in morphologically homogenous taxa with low vagility.

Made available in DSpace on 2022-04-28T19:50:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-03-01 The family Nemesiidae was once among the most species-rich of mygalomorph spider families. However, over the past few decades both morphological and molecular studies focusing on mygalomorph phylogeny have recovered the group as paraphyletic. Hence, the systematics of the family Nemesiidae has more recently been controversial, with numerous changes at the family-group level and the recognition of the supra-familial clade Nemesioidina. Indeed, in a recent study by Opatova and collaborators, six nemesiid genera were transferred to the newly re-established family Pycnothelidae. Despite these changes, 12 South American nemesiid genera remained unplaced, and classified as incertae sedis due to shortcomings in taxon sampling. Accordingly, we evaluate the phylogenetic relationships of South American nemesioid species and genera with the principle aim of resolving their family level placement. Our work represents the most exhaustive phylogenomic sampling for South American Nemesiidae by including nine of the 12 genera described for the continent. Phylogenetic relationships were reconstructed using 457 loci obtained using the spider Anchored Hybrid Enrichment probe set. Based on these results Nemesiidae, Pycnothelidae, Microstigmatidae and Cyrtaucheniidae are not considered monophyletic. Our study also indicates that the lineage including the genus Fufius requires elevation to the family level (Rhytidicolidae Simon, 1903 (NEW RANK)). In Pycnothelidae, we recognize/delimit five subfamilies (Diplothelopsinae, Pionothelinae (NEW SUBFAMILY), Prorachiinae (NEW SUBFAMILY), Pselligminae (NEW RANK), Pycnothelinae). We also transfer all the 12 South American nemesiid genera to Pycnothelidae: Chaco, Chilelopsis, Diplothelopsis, Flamencopsis, Hermachura, Longistylus, Lycinus, Neostothis, Prorachias, Psalistopoides, Pselligmus, Rachias. Additionally, we transferred the microstigmatid genus Xenonemesia to Pycnothelidae, and we propose the following generic synonymies and species transfers: Neostothis and Bayana are junior synonyms of Pycnothele (NEW SYNONYMY), as P. gigas and P. labordai, respectively (NEW COMBINATIONS); Hermachura is a junior synonym of Stenoterommata (NEW SYNONYMY), as S. luederwaldti (NEW COMBINATION); Flamencopsis is a junior synonym of Chilelopsis (NEW SYNONYMY), as C. minima (NEW COMBINATION); and Diplothelopsis is a junior synonym of Lycinus (NEW SYNONYMY), as L. ornatus and L. bonariensis (NEW COMBINATIONS). Considering the transferred genera and synonymies, Pycnothelidae now includes 15 described genera and 137 species. Finally, these results provide a robust phylogenetic framework that includes enhanced taxonomic sampling, for further resolving the biogeography and evolutionary time scale for the family Pycnothelidae. Sección Entomología Facultad de Ciencias Universidad de la República, Iguá 4225 Instituto de Investigaciones Biológicas Clemente Estable Ministerio de Educación y Cultura, Av. Italia 3318 Laboratório de Coleções Zoológicas Instituto Butantan, Av. Vital Brazil, 1500 Departamento de Biodiversidade Instituto de Biociências Universidade Estadual Paulista, Av. 24A, 1515 Department of Zoology Charles University Faculty of Science, Viničná 7 Instituto Nacional de Pesquisas da Amazônia Laboratório de Sistemática e Ecologia de Invertebrados do Solo, Av. André Araújo, 2936 – Petrópolis – Manaus Department of Entomology and Nematology University of California Davis, Academic Surge Building 1282 Departamento de Biodiversidade Instituto de Biociências Universidade Estadual Paulista, Av. 24A, 1515

Starrett, James, Bui, Ashley, McGinley, Rowan, Hebets, Jason E. Bond Eileen A. (2021): Phylogenomic Variation at the Population-Species Interface and Assessment of Gigantism in a Model Wolf Spider Genus (Lycosidae, Schizocosa). Insect Systematics and Diversity (AIFB) 5 (5): 1-13, DOI: 10.1093/isd/ixab016, URL: http://dx.doi.org/10.1093/isd/ixab016

Animal body size has important evolutionary implications. The wolf spider genus Schizocosa Chamberlin, 1904 has developed as a model for studies on courtship, with visual and vibratory signals receiving attention; however, body size has never been carefully evaluated. Although species of Schizocosa can be distinguished from their close relatives by differences in genitalic structures, male ornamentation, and behavior, some species are morphologically similar, making diagnosis, and identification difficult. Evaluation of species boundaries using genetic data across Schizocosa is limited. The similar species S. maxima Dondale & Redner, 1978 and S. mccooki (Montgomery, 1904) are separated predominantly on the basis of size differences, with S. maxima being larger. We evaluate the evolution of size in these two Schizocosa species distributed in western North America, where gigantism of S. maxima is hypothesized to occur, particularly in California. We sampled subgenomic data (RADseq) and inferred the phylogeny of S. mccooki, S. maxima, and relatives. We apply a variational autoencoder machine learning approach to visualize population structuring within widespread S. mccooki and evaluate size within the context of a comparative phylogenetic framework to test the hypotheses related to genetic clustering of populations and gigantism. Our data show S. mccooki populations are not genealogically exclusive with respect to S. maxima. Likewise, S. maxima individuals are not recovered as a lineage and do not form an isolated genetic cluster, suggesting that the observed differences in size cannot be used to accurately delimit species. The cause of gigantism in S. maxima remains unexplained, but provides a framework for future studies of size variation and speciation.

The mygalomorph spider genus Pionothele Purcell, 1902 comprises two nominal species known only from South Africa. We describe here a new species, Pionothelegobabebsp. n., from Namibia. This new species is currently only known from a very restricted area in the Namib Desert of western Namibia.

We report here the discovery of a remarkable new monotypic mygalomorph spider genus, known only from one geographical location along the central coast of California. The single relict species comprising Cryptocteniza kawtakn. gen. n. sp., is morphologically distinct and geographically isolated from other related genera, with its closest phylogenetic relatives found much further to the east in New Mexico and Arizona. Using a phylogenomic approach employing anchored hybrid enrichment, we reconstruct the evolutionary history of the family Euctenizidae Raven, 1985 to explore relationships among genera, affirmatively place previously undescribed taxa, explore rates of diversification, and reconstruct the group’s biogeography. A biogeographic analysis shows that extinction likely played a significant role in shaping the observed disjunct modern-day distribution of Cryptocteniza and its sister taxa. Our extinction hypothesis is further bolstered by a diversification rate analysis identifying considerably higher rates of speciation in other euctenizid lineages like AptostichusSimon, 1891. Consequently, changes in environmental conditions (or other related biotic and/or abiotic factors) may have spurred an adaptive radiation in related genera now widely distributed across the California Floristic Province biodiversity hotspot, with concomitant extinction in Cryptocteniza following the Miocene and establishment of a Mediterranean climate. Owing to its phylogenetic distinctiveness, incredibly narrow distribution and age, we show that Cryptocteniza meets all the criteria of an ‘Endangered Living Fossil’ and is consequently of grave conservation concern.

Background Mygalomorph spiders represent a diverse, yet understudied lineage for which genomic level data has only recently become accessible through high-throughput genomic and transcriptomic sequencing methods. The Aptostichus atomarius species complex (family Euctenizidae) includes two coastal dune endemic members, each with inland sister species – affording exploration of dune adaptation associated patterns at the transcriptomic level. We apply an RNAseq approach to examine gene family conservation across the species complex and test for patterns of positive selection along branches leading to dune endemic species. Results An average of ~ 44,000 contigs were assembled for eight spiders representing dune (n = 2), inland (n = 4), and atomarius species complex outgroup taxa (n = 2). Transcriptomes were estimated to be 64% complete on average with 77 spider reference orthologs missing from all taxa. Over 18,000 orthologous gene clusters were identified within the atomarius complex members, > 5000 were detected in all species, and ~ 4700 were shared between species complex members and outgroup Aptostichus species. Gene family analysis with the FUSTr pipeline identified 47 gene families appearing to be under selection in the atomarius ingroup; four of the five top clusters include sequences strongly resembling other arthropod venom peptides. The COATS pipeline identified six gene clusters under positive selection on branches leading to dune species, three of which reflected the preferred species tree. Genes under selection were identified as Cytochrome P450 2c15 (also recovered in the FUSTr analysis), Niemann 2 Pick C1-like, and Kainate 2 isoform X1. Conclusions We have generated eight draft transcriptomes for a closely related and ecologically diverse group of trapdoor spiders, identifying venom gene families potentially under selection across the Aptostichus atomarius complex and chemosensory-associated gene families under selection in dune endemic lineages.

Determining species boundaries forms an important foundation for biological research. However, the results of molecular species delimitation can vary with the data sets and methods that are used. Here we use a two-step approach to delimit species in the genus Heptathela, a group of primitively segmented trapdoor spiders that are endemic to Japanese islands. Morphological evidence suggests the existence of 19 species in the genus. We tested this initial species hypothesis by using six molecular species-delimitation methods to analyse 180 mitochondrial COI sequences of Heptathela sampled from across the known range of the genus. We then conducted a set of more focused analyses by sampling additional genetic markers from the subset of taxa that were inconsistently delimited by the single-locus analyses of mitochondrial DNA. Multilocus species delimitation was performed using two Bayesian approaches based on the multispecies coalescent. Our approach identified 20 putative species among the 180 sampled individuals of Heptathela. We suggest that our two-step approach provides an efficient strategy for delimiting species while minimizing costs and computational time.

Tarantula spider systematics has long been considered problematic. Species diagnosis and phylogenetic hypotheses have historically relied on morphological features, which are known to be relatively conserved and/or highly homoplastic across the family. Morphology-based attempts to clarify the phylogeny of the highly diverse New World Theraphosinae, have only been moderately successful, and the time-frame of tarantulas' evolution is nearly terra incognita. Here we present a molecular phylogenetic analysis of the Theraphosinae genus Bonnetina and related lineages, employing one mitochondrial (COI) and five nuclear (ITS1, EF1G, MID1IP1, MRPL44, and I3568) loci. We also perform ancestral state reconstruction of a newly formulated morphological data matrix. Our analysis includes 47 species placed in 17 genera and other undetermined lineages. We obtained well resolved and supported topologies. COI and EF1G substitution rates were much lower than the values generally accepted for mygalomorph evolution, with substantial rate heterogeneity among lineages. The origin of Theraphosinae was dated during the Late Cretaceous, followed by rapid diversification into the three recently proposed Theraphosinae tribes. North and Central American Hapalopini (including Bonnetina) form a monophyletic group that likely originated during the Oligocene to a dispersing ancestor from the then isolated South America. A clade that includes all but one Bonnetina species is estimated to have originated in the early Miocene and is the sister group of two morphologically divergent undescribed species. Morphological homoplasy is extensive across the tree. The two features that diagnose Bonnetina are homoplastic, but in combination still define the genus. Finally, we establish three groups of species within Bonnetina. Our results challenge the reliability of morphological characters for phylogenetic reconstruction in Theraphosinae, and indicate caution when interpreting Theraphosidae supra-specific classification in absence of a solid phylogenetic framework. They also question the dependability of universal substitution rates of COI and EF1G to calibrate phylogenetic analyses across Mygalomorphae.

Author(s): Chamberland, L; McHugh, A; Kechejian, S; Binford, GJ; Bond, JE; Coddington, J; Dolman, G; Hamilton, CA; Harvey, MS; Kuntner, M; Agnarsson, I | Abstract: Aim: We explore the evolutionary history of the ogre-faced spiders (Deinopis) from their Early Cretaceous origins to present day. Specifically, we investigate how vicariance and dispersal have shaped distribution patterns of this lineage. Within the Caribbean, we test the role of GAARlandia, a hypothesized land bridge that connected South America to the Greater Antilles during the Eocene–Oligocene transition (~35–33nMa), in the biogeography of Deinopis. Taxon: Araneae: Deinopidae: Deinopis. Location: Caribbean islands, with additional global exemplars. Methods: Combining standard Sanger sequence data with an Anchored Hybrid Enrichment (AHE) phylogenomic dataset, we use Bayesian inference to estimate the phylogenetic relationships of Deinopis. “BioGeoBEARS” is used to test the GAARlandia hypothesis, and to pinpoint major dispersal events in the biogeographic history of Deinopis. Results: The phylogeny supports the nesting of a Caribbean clade within a continental grade. Model comparisons indicate GAARlandia as the best fitting model, and the biogeographic analyses reflect the geologic history within the Caribbean. Ancient and recent overwater dispersal events are also indicated within this lineage. There is also an ancient 113nMa split into Old and New World clades. Main Conclusions: The Deinopis phylogeny corresponds well with geography. This is reflected in the support for the GAARlandia land bridge hypothesis and the phylogenetic relationships within and among Caribbean islands mirroring nuances of Caribbean geologic history. Overwater dispersal also plays an important role in the biogeographic history of this lineage as implicated in the colonization of the volcanic and sedimentary Lesser Antilles and in a “reverse” colonization of North America. The spider family Deinopidae is an ancient lineage with origins dating back to Gondwana. While overwater dispersal has clearly played a role in the biogeography of the genus, the Deinopis phylogeny bears a strong signature of ancient geological events.

Chionanthus retusus and most Osmanthus spp. possess torus-bearing intervascular pit membranes in their woods. Because the genera involved are thought to be closely related and are members of the subtribe Oleinae, we hypothesized that torus morphology should be similar across taxa. A study combining light, scanning electron, and atomic force microscopy indicates that tori in both genera comprise a bipartite thickening containing a central pustular region and an encircling corona. Removal of incrusting material from the torus exposes subtending sets of parallel microfibrils. We hypothesize that the torus structures of C. retusus and Osmanthus spp. (as represented by O. armatus) have the same morphology. Optimizing torus-bearing pits on published molecular phylogenies of the subtribe Oleinae indicates parallel evolution as an explanation for torus similarity between these two groups, although a robust and well-resolved phylogeny of the Oleaceae is still lacking. A brief study of the wood anatomy of Olea dioica was also undertaken. This species is a member of the subgenus Tetrapilus and thought to be closely related to torus-bearing genera of the Oleaceae. Despite the close relationship, no tori were observed in O. dioica.

We present a phylogenetic analysis of spiders using a dataset of 932 spider species, representing 115 families (only the family Synaphridae is unrepresented), 700 known genera, and additional representatives of 26 unidentified or undescribed genera. Eleven genera of the orders Amblypygi, Palpigradi, Schizomida and Uropygi are included as outgroups. The dataset includes six markers from the mitochondrial (12S, 16S, COI) and nuclear (histone H3, 18S, 28S) genomes, and was analysed by multiple methods, including constrained analyses using a highly supported backbone tree from transcriptomic data. We recover most of the higher-level structure of the spider tree with good support, including Mesothelae, Opisthothelae, Mygalomorphae and Araneomorphae. Several of our analyses recover Hypochilidae and Filistatidae as sister groups, as suggested by previous transcriptomic analyses. The Synspermiata are robustly supported, and the families Trogloraptoridae and Caponiidae are found as sister to the Dysderoidea. Our results support the Lost Tracheae clade, including Pholcidae, Tetrablemmidae, Diguetidae, Plectreuridae and the family Pacullidae (restored status) separate from Tetrablemmidae. The Scytodoidea include Ochyroceratidae along with Sicariidae, Scytodidae, Drymusidae and Periegopidae; our results are inconclusive about the separation of these last two families. We did not recover monophyletic Austrochiloidea and Leptonetidae, but our data suggest that both groups are more closely related to the Cylindrical Gland Spigot clade rather than to Synspermiata. Palpimanoidea is not recovered by our analyses, but also not strongly contradicted. We find support for Entelegynae and Oecobioidea (Oecobiidae plus Hersiliidae), and ambiguous placement of cribellate orb-weavers, compatible with their non-monophyly. Nicodamoidea (Nicodamidae plus Megadictynidae) and Araneoidea composition and relationships are consistent with recent analyses. We did not obtain resolution for the titanoecoids (Titanoecidae and Phyxelididae), but the Retrolateral Tibial Apophysis clade is well supported. Penestomidae, and probably Homalonychidae, are part of Zodarioidea, although the latter family was set apart by recent transcriptomic analyses. Our data support a large group that we call the marronoid clade (including the families Amaurobiidae, Desidae, Dictynidae, Hahniidae, Stiphidiidae, Agelenidae and Toxopidae). The circumscription of most marronoid families is redefined here. Amaurobiidae include the Amaurobiinae and provisionally Macrobuninae. We transfer Malenellinae (Malenella, from Anyphaenidae), Chummidae (Chumma) (new syn.) and Tasmarubriinae (Tasmarubrius, Tasmabrochus and Teeatta, from Amphinectidae) to Macrobuninae. Cybaeidae are redefined to include Calymmaria, Cryphoeca, Ethobuella and Willisius (transferred from Hahniidae), and Blabomma and Yorima (transferred from Dictynidae). Cycloctenidae are redefined to include Orepukia (transferred from Agelenidae) and Pakeha and Paravoca (transferred from Amaurobiidae). Desidae are redefined to include five subfamilies: Amphinectinae, with Amphinecta, Mamoea, Maniho, Paramamoea and Rangitata (transferred from Amphinectidae); Ischaleinae, with Bakala and Manjala (transferred from Amaurobiidae) and Ischalea (transferred from Stiphidiidae); Metaltellinae, with Austmusia, Buyina, Calacadia, Cunnawarra, Jalkaraburra, Keera, Magua, Metaltella, Penaoola and Quemusia; Porteriinae (new rank), with Baiami, Cambridgea, Corasoides and Nanocambridgea (transferred from Stiphidiidae); and Desinae, with Desis, and provisionally Poaka (transferred from Amaurobiidae) and Barahna (transferred from Stiphidiidae). Argyroneta is transferred from Cybaeidae to Dictynidae. Cicurina is transferred from Dictynidae to Hahniidae. The genera Neoramia (from Agelenidae) and Aorangia, Marplesia and Neolana (from Amphinectidae) are transferred to Stiphidiidae. The family Toxopidae (restored status) includes two subfamilies: Myroinae, with Gasparia, Gohia, Hulua, Neomyro, Myro, Ommatauxesis and Otagoa (transferred from Desidae); and Toxopinae, with Midgee and Jamara, formerly Midgeeinae, new syn. (transferred from Amaurobiidae) and Hapona, Laestrygones, Lamina, Toxops and Toxopsoides (transferred from Desidae). We obtain a monophyletic Oval Calamistrum clade and Dionycha; Sparassidae, however, are not dionychans, but probably the sister group of those two clades. The composition of the Oval Calamistrum clade is confirmed (including Zoropsidae, Udubidae, Ctenidae, Oxyopidae, Senoculidae, Pisauridae, Trechaleidae, Lycosidae, Psechridae and Thomisidae), affirming previous findings on the uncertain relationships of the "ctenids" Ancylometes and Cupiennius, although a core group of Ctenidae are well supported. Our data were ambiguous as to the monophyly of Oxyopidae. In Dionycha, we found a first split of core Prodidomidae, excluding the Australian Molycriinae, which fall distantly from core prodidomids, among gnaphosoids. The rest of the dionychans form two main groups, Dionycha part A and part B. The former includes much of the Oblique Median Tapetum clade (Trochanteriidae, Gnaphosidae, Gallieniellidae, Phrurolithidae, Trachelidae, Gnaphosidae, Ammoxenidae, Lamponidae and the Molycriinae), and also Anyphaenidae and Clubionidae. Orthobula is transferred from Phrurolithidae to Trachelidae. Our data did not allow for complete resolution for the gnaphosoid families. Dionycha part B includes the families Salticidae, Eutichuridae, Miturgidae, Philodromidae, Viridasiidae, Selenopidae, Corinnidae and Xenoctenidae (new fam., including Xenoctenus, Paravulsor and Odo, transferred from Miturgidae, as well as Incasoctenus from Ctenidae). We confirm the inclusion of Zora (formerly Zoridae) within Miturgidae.

Aim We test the hypothesis that the opening of the Western Mediterranean basin drove the diversification of the trap-door spider genus Ummidia by reconstructing the phylogeny and inferring a temporal framework of diversification. Additionally, we assess niche interchangeability of three Ummidia species to test the role of dispersal in shaping their present-day distribution. Location Western Mediterranean, encompassing the known distribution range of Ummidia on the Iberian Peninsula and Northern Africa. Methods We use multi-locus data and employ both gene concatenation and coalescent species-tree approaches in phylogenetic reconstruction and Bayesian divergence estimation. Species distribution modelling is used to assess the ecological preferences of three species and evaluate ecological interchangeability. Results The diversification time frame inferred for the basal split of Ummidia and subsequent diversification correlates with the tectonic movements involved in the phases of the opening of the Western Mediterranean. The basal split (24 Ma) correlates with the opening of the Valencia Trough, the split of the Maghrebian clade (16.54 Ma) with the separation of the Kabylies and Betic-Rif blocks. A back-colonization of the Iberian Peninsula from northern Africa was detected, presumably occurring via land bridges during the Messinian salinity crisis. The environmental preferences of Ummidia species indicate that U. algarve and adjacent Ummidia sp. ‘Tarifa’ are ecologically interchangeable. Main conclusions Tectonic movements involved in the opening of the Western Mediterranean shaped the distribution and diversity of extant Mediterranean Ummidia lineages. Despite the putative ability of Ummidia for airborne dispersal, observed phylogeographical patterns and isolation of ecologically interchangeable and geographically proximate species indicate that long-distance dispersal events are rare and the present-day distribution may be due to vicariant events driven by drifting microplates. Finally, several additional evolutionary independent lineages that may correspond to putative new species were detected.

Phylogeographic studies frequently result in the elevation of subspecific taxa to species given monophyly, or the synonymy of subspecies that are not monophyletic. However, given limited or incongruent datasets, retention of subspecies can be useful to describe hypothesized incipient species or to illustrate interesting biological phenomena driving morphological diversity. Four subspecific taxa have been used to describe largely allopatric geographic variation within the species Pseudotriton ruber, a plethodontid salamander occupying stream and spring habitats across eastern North America: P. r. vioscai occurs in lowland Coastal Plain habitats, while P. r. ruber, P. r. nitidus, and P. r. schencki occupy upland regions in and around the Appalachian Mountains. Pseudotriton ruber co-occurs through its distribution with the aposematic newt Notophthalmus viridescens, and both species are hypothesized to be part of a Müllerian mimicry complex. In this study, we sequenced regions of two mitochondrial (cytochrome b, NADH dehydrogenase subunit 2) and one single copy nuclear protein-coding gene (pro-opiomelanocortin) from individuals sampled across much of the distribution of P. ruber and then used maximum-likelihood and Bayesian phylogenetic inference to test the monophyly of subspecies, reconstruct biogeographic history, and make inferences about morphological evolution. Phylogeographic hypotheses from mitochondrial and nuclear datasets described structure among populations of P. ruber which separated Coastal Plain and upland Appalachian populations, but subspecies were not monophyletic. Biogeographic reconstruction estimated the ancestor of all populations to have occupied and initially diverged in the Coastal Plain during the Pliocene (∼3.6mya), before one lineage subsequently invaded upland areas of Appalachia. Bold bright coloration of high elevation subspecies P. r. nitidus and P. r. schencki appears to have evolved twice. We hypothesize that the Müllerian mimicry complex with N. viridescens and P. ruber may provide a selective mechanism driving the co-evolution of striking bright and dull morphological variation among populations of both species. While P. ruber subspecies were not consistent with our criteria for diagnosing species (monophyly) and therefore could not be elevated to species, we advocate for the retention of subspecies because they describe hypotheses about an incipient species (P. r. vioscai) and how Müllerian mimicry may shape morphological diversity of species.

Mate choice, copulation, genital morphology, and sperm storage are not very well understood in millipedes. The use of three-dimensional x-ray computed tomography (μCT) provides new morphological data regarding millipede reproductive systems in both the female and male, including chitinous sclerites and membranes, muscles, glands, oviducts, and sperm conduits. Here we present a complete integrated account of the morphology and function of the female genital organs in the family Polydesmidae (Diplopoda: Polydesmida) using μCT, UV fluorescence imaging, and scanning electron microscopy. These data allow us to consider competing hypotheses regarding millipede vulva formation. We additionally present the morphology of copulatory interface in Pseudopolydesmus Attems, 1898 using images of a mating pair in copula and by simulating the interface of the organs using 3D models from μCT, allowing us to tentatively identify a lock-and-key-like mechanism. Finally, we use μCT to reveal the topology of the seminal canal in the gonopod of male Pseudopolydesmus, a topic that has remained unresolved for nearly 80 years.

Much genomic-scale, especially transcriptomic, data on spider phylogeny has accumulated in the last few years. These data have recently been used to investigate the diverse architectures and the origin of spider webs, concluding that the ancestral spider spun no foraging web, that spider webs evolvedde novo10–14 times, and that the orb web evolved at least three times. These findings in fact result from a particular phylogenetic character coding strategy, specifically coding theabsenceof webs as logically equivalent, and homologous to, 10 other observable (i.e., not absent) web architectures. “Absence” of webs should be regarded as inapplicable data. To be analyzed properly by character optimization algorithms, it should be coded as “?” because these codes—or their equivalent—are handled differently by such algorithms. Additional problems include critical misspellings of taxon names from one analysis to the next (misspellings cause some optimization algorithms to drop terminals, which affects taxon sampling and results), and mistakes in spider natural history. In sum, the method causes character optimization algorithms to produce counter-intuitive results, and does not distinguish absence from secondary loss. Proper treatment of missing entries and corrected data instead imply that foraging webs are primitive for spiders and that webs have been lost ∼5–7 times, not gained 10–14 times. The orb web, specifically, may be homologous (originated only once) although lost 2–6 times.

Instances of sexual size dimorphism (SSD) provide the context for rigorous tests of biological rules of size evolution, such as Cope’s rule (phyletic size increase), Rensch’s rule (allometric patterns of male and female size), as well as male and female body size optima. In certain spider groups, such as the golden orbweavers (Nephilidae), extreme female-biased SSD (eSSD, female:male body length \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$\ge$\end{document}2) is the norm. Nephilid genera construct webs of exaggerated proportions, which can be aerial, arboricolous, or intermediate (hybrid). First, we established the backbone phylogeny of Nephilidae using 367 anchored hybrid enrichment markers, then combined these data with classical markers for a reference species-level phylogeny. Second, we used the phylogeny to test Cope and Rensch’s rules, sex specific size optima, and the coevolution of web size, type, and features with female and male body size and their ratio, SSD. Male, but not female, size increases significantly over time, and refutes Cope’s rule. Allometric analyses reject the converse, Rensch’s rule. Male and female body sizes are uncorrelated. Female size evolution is random, but males evolve toward an optimum size (3.2–4.9 mm). Overall, female body size correlates positively with absolute web size. However, intermediate sized females build the largest webs (of the hybrid type), giant female Nephila and Trichonephila build smaller webs (of the aerial type), and the smallest females build the smallest webs (of the arboricolous type). We propose taxonomic changes based on the criteria of clade age, monophyly and exclusivity, classification information content, and diagnosability. Spider families, as currently defined, tend to be between 37 million years old and 98 million years old, and Nephilidae is estimated at 133 Ma (97–146), thus deserving family status. We, therefore, resurrect the family Nephilidae Simon 1894 that contains Clitaetra Simon 1889, the Cretaceous GeratonephilaPoinar and Buckley (2012), Herennia Thorell 1877, IndoetraKuntner 2006, new rank, Nephila Leach 1815, Nephilengys L. Koch 1872, Nephilingis Kuntner 2013, Palaeonephila Wunderlich 2004 from Tertiary Baltic amber, and TrichonephilaDahl 1911, new rank. We propose the new clade Orbipurae to contain Araneidae Clerck 1757, Phonognathidae Simon 1894, new rank, and Nephilidae. Nephilid female gigantism is a phylogenetically ancient phenotype (over 100 Ma), as is eSSD, though their magnitudes vary by lineage.

With fossil representatives from the Silurian capable of respiring atmospheric oxygen, millipedes are among the oldest terrestrial animals, and likely the first to acquire diverse and complex chemical defenses against predators. Exploring the origin of complex adaptive traits is critical for understanding the evolution of Earth’s biological complexity, and chemical defense evolution serves as an ideal study system. The classic explanation for the evolution of complexity is by gradual increase from simple to complex, passing through intermediate “stepping stone” states. Here we present the first phylogenetic-based study of the evolution of complex chemical defenses in millipedes by generating the largest genomic-based phylogenetic dataset ever assembled for the group. Our phylogenomic results demonstrate that chemical complexity shows a clear pattern of escalation through time. New pathways are added in a stepwise pattern, leading to greater chemical complexity, independently in a number of derived lineages. This complexity gradually increased through time, leading to the advent of three distantly related chemically complex evolutionary lineages, each uniquely characteristic of each of the respective millipede groups.

Here we show that the most venomous spiders in the world are phylogenetically misplaced. Australian atracine spiders (family Hexathelidae), including the notorious Sydney funnel-web spider Atrax robustus, produce venom peptides that can kill people. Intriguingly, eastern Australian mouse spiders (family Actinopodidae) are also medically dangerous, possessing venom peptides strikingly similar to Atrax hexatoxins. Based on the standing morphology-based classification, mouse spiders are hypothesized distant relatives of atracines, having diverged over 200 million years ago. Using sequence-capture phylogenomics, we instead show convincingly that hexathelids are non-monophyletic, and that atracines are sister to actinopodids. Three new mygalomorph lineages are elevated to the family level, and a revised circumscription of Hexathelidae is presented. Re-writing this phylogenetic story has major implications for how we study venom evolution in these spiders, and potentially genuine consequences for antivenom development and bite treatment research. More generally, our research provides a textbook example of the applied importance of modern phylogenomic research. Fil: Hedin, Marshal. San Diego State University; Estados Unidos Fil: Derkarabetian, Shahan. University of California; Estados Unidos. San Diego State University; Estados Unidos Fil: Ramirez, Martin Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentina Fil: Vink, Cor. Canterbury Museum Christchurch; Nueva Zelanda Fil: Bond, Jason E.. Auburn University; Estados Unidos

Aim Phylogeographical studies in the Mojave and Sonoran deserts often find genetic discontinuities that pre-date the Pleistocene. A recent synthesis of phylogeographical data, called the Mojave Assembly Model, provides a hypothesis for the historical assembly of these desert biotas but does not adequately capture the complexity of pre-Pleistocene vicariance events. We tested this model and assessed pre-Pleistocene divergences by exploring the phylogeography of the Aphonopelma mojave group, which is composed of turret-building tarantula species from the Mojave and Sonoran deserts. Location Mojave and Sonoran deserts, south-western USA. Methods We augmented the sampling from a previous study by sequencing mitochondrial DNA (COI) from new material of the A. mojave group. We used phylogenetic and network analyses to identify clades and a molecular clock and lineages-through-time plots (LTT plots) to explore the timing and tempo of diversification. We tested for demographic expansion using neutrality tests and mismatch distributions. Species distribution models (SDMs) were constructed to compare current suitable habitat to that at the Last Glacial Maximum (LGM). Results Phylogenetic, network and molecular-clock analyses identified six major clades that probably diverged during the late Miocene. The rate of diversification appears to have slowed during the Pliocene. Most clades exhibit signals of recent demographic expansion. SDMs predicted that suitable habitat shifted south and to lower elevations during the LGM. Main conclusions Phylogeographical analyses suggest that the A. mojave group experienced a burst of diversification in the late Miocene, followed by population expansions during the Pleistocene. Six major clades with origins in the late Miocene cannot be adequately explained by the Mojave Assembly Model. We propose the novel hypothesis that Miocene extensional tectonics caused populations to diverge in allopatry by producing low-elevation habitat barriers. Geological models, such as kinematic reconstructions, provide an ideal but underutilized framework for testing biogeographical hypotheses in these deserts and the wider Basin and Range Province.

We present the first genome-wide molecular phylogeny of jumping spiders (Araneae: Salticidae), inferred from Anchored Hybrid Enrichment (AHE) sequence data. From 12 outgroups plus 34 salticid taxa representing all but one subfamily and most major groups recognized in previous work, we obtained 447 loci totalling 96,946 aligned nucleotide sites. Our analyses using concatenated likelihood, parsimony, and coalescent methods (ASTRAL and SVDQuartets) strongly confirm most previous results, resolving as monophyletic the Spartaeinae, Salticinae (with the hisponines sister), Salticoida, Amycoida, Saltafresia, and Simonida. The agoriines, previously difficult to place beyond subfamily, are finally placed confidently within the saltafresians as relatives of the chrysillines and hasariines. Relationships among the baviines, astioids, marpissoids, and saltafresians remain uncertain, though our analyses tentatively conclude the first three form a clade together. Deep relationships, among the seven subfamilies, appear to be largely resolved, with spartaeines, lyssomanines, and asemoneines forming a clade. In most analyses, Onomastus (representing the onomastines) is strongly supported as sister to the hisponines plus salticines. Overall, the much-improved resolution of many deep relationships despite a relatively sparse taxon sample suggests AHE is a promising technique for salticid phylogenetics.

Florida scrub is a xeric ecosystem associated with the peninsula's sand ridges, whose intermittent Pliocene-Pleistocene isolation is considered key to scrub endemism. One scrub origin hypothesis posits endemics were sourced by the Pliocene dispersal of arid-adapted taxa from southwestern North America; a second invokes Pleistocene migration within eastern North America. Only one study to date has explicitly tested these competing hypotheses, supporting an eastern origin for certain scrub angiosperms. For further perspective, we conducted a genetic analysis of an endemic arthropod, the Florida sand cockroach (

Onymacris brainei Penrith, 1984 – the most recent species of Onymacris to be described – is known only from its type locality in the Namib Desert, adjacent to the Cunene River in northern Namibia. No additional specimens are known to have been collected beyond the type series. Herein, we report on eight specimens discovered at a second site near the original locality. DNA from four beetles was used to determine the phylogenetic placement of O. brainei among congeners, based on sequence data from one nuclear (histone III) and two mitochondrial (cox1, cox2) genes. Maximum likelihood analysis identifies O. brainei as a member of the ‘white’ Onymacris clade, in which it forms a strongly supported subclade with O. bicolor and O. marginipennis. More broadly, its phylogenetic placement augments previous molecular results that revealed a sister taxon relationship between the ‘white’ Onymacris and a second genus, Physadesmia. The paraphyly of Onymacris with respect to Physadesmia highlights a need for nomenclatural change, but revision should await acquisition of genetic data for the few species outstanding in both genera.

Onymacris brainei Penrith, 1984 – the most recent species of Onymacris to be described – is known only from its type locality in the Namib Desert, adjacent to the Cunene River in northern Namibia. No additional specimens are known to have been collected beyond the type series. Herein, we report on eight specimens discovered at a second site near the original locality. DNA from four beetles was used to determine the phylogenetic placement of O. brainei among congeners, based on sequence data from one nuclear (histone III) and two mitochondrial (cox1, cox2) genes. Maximum likelihood analysis identifies O. brainei as a member of the 'white' Onymacris clade, in which it forms a strongly supported subclade with O. bicolor and O. marginipennis. More broadly, its phylogenetic placement augments previous molecular results that revealed a sister taxon relationship between the 'white' Onymacris and a second genus, Physadesmia. The paraphyly of Onymacris with respect to Physadesmia highlights a need for nomenclatural change, but revision should await acquisition of genetic data for the few species outstanding in both genera.

Summary Spiders represent an ancient predatory lineage known for their extraordinary biomaterials, including venoms and silks. These adaptations make spiders key arthropod predators in most terrestrial ecosystems. Despite ecological, biomedical, and biomaterial importance, relationships among major spider lineages remain unresolved or poorly supported [1]. Current working hypotheses for a spider ‘‘backbone’’ phylogeny are largely based on morphological evidence, as most molecular markers currently employed are generally inadequate for resolving deeper-level relationships. We present here a phylogenomic analysis of spiders including taxa representing all major spider lineages. Our robust phylogenetic hypothesis recovers some fundamental and uncontroversial spider clades, but rejects the prevailing paradigm of a monophyletic Orbiculariae, the most diverse lineage, containing orb-weaving spiders. Based on our results, the orb web either evolved much earlier than previously hypothesized and is ancestral for a majority of spiders or else it has multiple independent origins, as hypothesized by precladistic authors. Cribellate deinopoid orb weavers that use mechanically adhesive silk are more closely related to a diverse clade of mostly webless spiders than to the araneoid orb-weaving spiders that use adhesive droplet silks. The fundamental shift in our understanding of spider phylogeny proposed here has broad implications for interpreting the evolution of spiders, their remarkable biomaterials, and a key extended phenotype—the spider web.