Revised classification of the New World Cylapini (Heteroptera: Miridae: Cylapinae): taxonomic review of the genera Cylapinus, Cylapoides and Peltidocylapus and a morphology-based phylogenetic analysis of tribe Cylapini

Cylapini, as currently circumscribed, is a relatively small group of plant bugs currently comprising 17 genera and 65 species. Most representatives of the tribe are distributed in the New World (10 genera and 47 species) with other members occurring in the Afrotropical, Oriental, and Australian regions. They have primarily tropical and subtropical distributions with only a few members inhabiting temperate regions. This paper provides a taxonomic review of three of the New World Cylapini genera: Cylapinus Carvalho, 1986, Cylapoides Carvalho, 1952, and Peltidocylapus Poppius, 1909. Most species are diagnosed and redescribed. Eight new species are described as new: Cylapinus yasunagai sp. nov., Peltidocylapus calyciformis sp. nov., P. caudatus sp. nov., P. ecuadorensis sp. nov., P. pallidus sp. nov., P. parallelus sp. nov., P. simplex sp. nov., and P. spinosus sp. nov. Cylapus festinabundus Bergroth, 1922 is transferred to Peltidocylapus (comb. nov.). Illustrations of male genitalia, scanning electron micrographs of selected structures of certain species, and an identification key of the genera Cylapinus, Cylapoides and Peltidocylapus are provided. Female genitalia are described and illustrated for the first time for most genera of Cylapini. A cladistic analysis of the tribe based on 81 morphological characters is presented as a contribution to the understanding of the ingroup relationships of Cylapini and its relationships with other groups of Cylapinae. The analysis comprises 30 ingroup species and 15 outgroup species. Both equal- and implied weighting parsimony analyses were used in the phylogenetic reconstruction. This analysis was based solely on morphological characters because an insufficient number of specimens suitable for molecular studies were available for most taxa. The study confirmed a close affinity of the taxa currently included in Cylapini, but the tribe was rendered paraphyletic by inclusion of the tribe Vanniini. The grouping comprising both Cylapini + Vanniini and most of its subordinated clades received low nodal support. Both analyses recovered a decisively supported clade comprising the New World genera Amapacylapus, Cylapus, Peltidocylapus, and Valdasus which accommodate most of the Cylapini species, justifying the recognition of the Cylapus complex suggested by previous authors. The results presented here are discussed and compared with previous phylogenetic hypotheses based on different datasets.

Improved resolution of recalcitrant nodes in the animal phylogeny through the analysis of genome gene content and morphology

An accurate phylogeny of animals is needed to clarify their evolution, ecology, and impact on shaping the biosphere. Although multi-gene alignments of up to several hundred thousand amino acids are nowadays routinely used to test hypotheses of animal relationships, some nodes towards the root of the animal phylogeny are proving hard to resolve. While the relationships of the non-bilaterian lineages, primarily sponges (Porifera) and comb jellies (Ctenophora), have received much attention since more than a decade, controversies about the phylogenetic position of the worm-like bilaterian lineage Xenacoelomorpha and the monophyly of the "Superphylum" Deuterostomia have more recently emerged. Here we independently analyse novel genome gene content and morphological datasets to assess patterns of phylogenetic congruence with previous amino-acid derived phylogenetic hypotheses. Using statistical hypothesis testing, we show that both our datasets very strongly support sponges as the sister group of all the other animals, Xenoacoelomorpha as the sister group of the other Bilateria, and largely support monophyletic Deuterostomia. Based on these results, we conclude that the last common animal ancestor may have been a simple, filter-feeding organism without a nervous system and muscles, while the last common ancestor of Bilateria might have been a small, acoelomate-like worm without a through gut.

Biotectonics of Sulawesi: Principles, methodology, and area relationships

Biotectonics is an approach to historical biogeography based on the analysis of independently derived biological and tectonic data, which we demonstrate using the island of Sulawesi as an example. We describe the tectonic development of Sulawesi and discuss the relationship between tectonic models and phylogenetic hypotheses. We outline the problem of interpreting areagrams based on single phylogenies and stress the importance of combining all available data into a general areagram. We analysed the distributions of Sulawesi area of endemism endemics (AEEs) using 30 published phylogenies, which were converted into paralogy-free taxon-area cladograms using the programme LisBeth (Zaragüeta-Bagalis et al. 2012) from which Adam’s consensus trees were constructed using PAUP (Swofford 2002). The results of our analyses show that the relationship between the areas of endemism is congruent with the terrane history of the island. A further 79 phylogenies of Sulawesi species with extralimital distributions were analysed to determine area relationships of Sulawesi within the broader Indo-Pacific region. We demonstrate the utility of data partitioning when dealing with areas that are geologically and biologically composite by showing that analysing Asian and Australasian elements of the Sulawesi biota separately produced general areagrams that avoid artifice and are interpretable in the light of current tectonic models.

A completely resolved phylogenetic tree of British spiders (Arachnida: Araneae)

The recent accumulation of increasingly densely sampled phylogenetic analyses of spiders has greatly advanced our understanding of evolutionary relationships within this group. Here, this diverse literature is reviewed and combined with earlier morphological analyses in an attempt to reconstruct the first fully resolved phylogeny for the spider fauna of the British Isles. The resulting tree highlights parts of the group where data are still too limited for a confident assessment of relationships, proposes a number of deviations from previously suggested phylogenetic hypotheses, and can serve as a framework for evolutionary and ecological interpretations of the biology of British spiders, as well as a starting point for future studies on a larger geographical scale.

Who’s who in Magelona: phylogenetic hypotheses under Magelonidae Cunningham & Ramage, 1888 (Annelida: Polychaeta)

Known as shovel head worms, members of Magelonidae comprise a group of polychaetes readily recognised by the uniquely shaped, dorso-ventrally flattened prostomium and paired ventro-laterally inserted papillated palps. The present study is the first published account of inferences of phylogenetic hypotheses within Magelonidae. Members of 72 species of Magelona and two species of Octomagelona were included, with outgroups including members of one species of Chaetopteridae and four of Spionidae. The phylogenetic inferences were performed to causally account for 176 characters distributed among 79 subjects, and produced 2,417,600 cladograms, each with 404 steps. A formal definition of Magelonidae is provided, represented by a composite phylogenetic hypothesis explaining seven synapomorphies: shovel-shaped prostomium, prostomial ridges, absence of nuchal organs, ventral insertion of palps and their papillation, presence of a burrowing organ, and unique body regionation. Octomagelona is synonymised with Magelona due to the latter being paraphyletic relative to the former. The consequence is that Magelonidae is monotypic, such that Magelona cannot be formally defined as associated with any phylogenetic hypotheses. As such, the latter name is an empirically empty placeholder, but because of the binomial name requirement mandated by the International Code of Zoological Nomenclature, the definition is identical to that of Magelonidae. Several key features for future descriptions are suggested: prostomial dimensions, presence/absence of prostomial horns, morphology of anterior lamellae, presence/absence of specialised chaetae, and lateral abdominal pouches. Additionally, great care must be taken to fully describe and illustrate all thoracic chaetigers in descriptions.

Towards a better understanding of the genus Sciurella Allman, 1883 (Cnidaria: Hydrozoa: Plumulariidae): evidence from an integrative study

The genus Sciurella Allman, 1883 is reassessed based on fertile specimens from Indonesia and Australia, using both morphological and genetic approaches. The genus is resurrected and kept distinct from Nemertesia Lamouroux, 1812 on the account of its long, tubular hydrothecae, and the gonothecae (of which only the female ones are known) provided with nematothecae. Stellate gonothecae correspond to S. indivisa Allman, 1883, while urn-shaped gonothecae are subjectively attributable to S. cylindrica (Kirchenpauer, 1876), comb. nov., a nominal species originally described based on sterile material. The taxonomy of the latter species is discussed in light of the available literature data, and Antennularia cylindrica Bale, 1884 is confidently assigned to its synonymy. Plumularia dolichotheca Allman, 1883 is provisionally transferred to Sciurella, as S. dolichotheca comb. nov., pending the discovery of fertile specimens and reliable evidence from molecular studies. The newly-generated genetic data for S. indivisa and S. cylindrica clearly confirm the distinction between Sciurella and Nemertesia, the two genera occupying divergent positions within the Plumulariidae phylogenetic hypotheses.

Tackling the phylogenetic conundrum of Hydroidolina (Cnidaria: Medusozoa: Hydrozoa) by assessing competing tree topologies with targeted high-throughput sequencing

Higher-level relationships of the Hydrozoan subclass Hydroidolina, which encompasses the vast majority of medusozoan cnidarian species diversity, have been elusive to confidently infer. The most widely adopted phylogenetic framework for Hydroidolina based on ribosomal RNA data received low support for several higher level relationships. To address this issue, we developed a set of RNA baits to target more than a hundred loci from the genomes of a broad taxonomic sample of Hydroidolina for high-throughput sequencing. Using these data, we inferred the relationships of Hydroidolina using maximum likelihood and Bayesian approaches. Both inference methods yielded well-supported phylogenetic hypotheses that largely agree with each other. Using maximum likelihood and Baysian hypothesis testing frameworks, we found that several alternate topological hypotheses proposed previously may be rejected in light of the genomic data generated for this study. Both the maximum likelihood and Bayesian topologies inferred herein consistently score well across testing frameworks, suggesting that their consensus represents the most likely phylogenetic hypothesis of Hydroidolina. This phylogenetic framework places Aplanulata as sister lineage to the remainder of Hydroidolina. This is a strong deviation from previous phylogenetic analyses that placed Capitata or Siphonophorae as sister group to the remainder of Hydroidolina. Considering that Aplanulata represents a lineage comprised of species that for the most part possess a life cycle involving a solitary polyp and free-swimming medusa stage, the phylogenetic hypotheses presented herein have potentially large implications for clarifying the evolution of life cycles, coloniality, and the division of labor in Hydrozoa as taxon sampling for phylogenetic analyses becomes more complete.

Touch me carefully: a step towards understanding morphological diversity in the South American spiny sunflowers (Compositae, Barnadesioideae)

The subfamily Barnadesioideae (Compositae) is endemic to South America, comprising 10 genera and 80 species of mostly spiny herbs, subshrubs, shrubs, trees, or woody vines distributed from Venezuela to Argentina. Three genera, Dasyphyllum (27 species), Chuquiraga (22 spp.) and Barnadesia (19 spp.) contain 85% of the species, while the other seven genera (Archidasyphyllum, Arnaldoa, Doniophyton, Duseniella, Fulcaldea, Huarpea, and Schlechtendalia) are represented by up to three species each. Most species are found in xeric areas in the Andean and Patagonian regions—as in the Páramos, Puna and Patagonian steppe vegetation—with a secondary center of diversity in eastern South America. Previous phylogenetic hypotheses have clarified the relationships within the subfamily, showing that there are many non-monophyletic groups in different taxonomic ranks. As a result, taxonomic changes have been proposed over recent decades in order to reflect classifications comprising only monophyletic groups. In the present study, we provide a generic synopsis of the subfamily Barnadesioideae based on the most recent generic circumscriptions, including a key, expanded morphological descriptions, information on geographical distribution and habitat, photographs and taxonomic notes for all genera.

High lineage survivorship across the end-Devonian Mass Extinction suggested by a remarkable new Late Devonian actinopterygian

Actinopterygian (ray-finned) fishes represent the principal vertebrate group in aquatic settings. This dominance is often attributed to their apparent success in the aftermath of the end-Devonian extinction. Increases in taxonomic and morphological diversity in the early Carboniferous, coupled with phylogenetic hypotheses implying the survival of few Devonian lineages, contribute to a model of explosive post-extinction radiation. However, most actinopterygian fossils from within a ca. 20 Myr window surrounding the end-Devonian extinction remain poorly known, contributing to uncertainty about these patterns. Here we present detailed anatomical data for an exceptionally preserved but diminutive ray-finned fish from within this gap, ~7 Myr prior to the Devonian-Carboniferous boundary. Representing a new genus and species, it bears a series of derived anatomical features otherwise known only from Carboniferous and younger taxa. It nests phylogenetically within a clade of post-Devonian species and, in an expanded phylogenetic analysis incorporating other previously neglected taxa, draws at least ten lineages of Carboniferous actinopterygians into the Late Devonian. This suggests phenotypically cryptic divergence among ray-finned fishes in the latest Devonian, followed by more conspicuous diversification in feeding and locomotor structures in the Carboniferous. This revised model finds parallels in patterns emerging for other clades, and provides a refined perspective on key events early in the history of a group that today contains half of all living vertebrate species.