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Providing accurate animals' phylogenies rely on increasing knowledge of neglected phyla. Tardigrada diversity evaluated in broad phylogenies (among phyla) is biased towards eutardigrades. A comprehensive phylogeny is demanded to establish the representative diversity and propose a more natural classification of the phylum. So, we have performed multilocus (18S rRNA and 28S rRNA) phylogenies with Bayesian inference and maximum likelihood. We propose the creation of a new class within Tardigrada, erecting the order Apochela (Eutardigrada) as a new Tardigrada class, named Apotardigrada comb. n. Two groups of evidence support its creation: (a) morphological, presence of cephalic appendages, unique morphology for claws (separated branches) and wide‐elongated buccopharyngeal apparatus without placoids, and (b) phylogenetic support based on molecular data. Consequently, order Parachela is suppressed and its superfamilies erected as orders within Eutardigrada, maintaining their current names. We propose a new classification within the family Echiniscidae (Echiniscoidea, Heterotardigrada) with morphological and phylogenetic support: (a) subfamily Echiniscinae subfam. n., with two tribes Echiniscini tribe n. and Bryodelphaxini tribe n.; (b) subfamily Pseudechiniscinae subfam. n., with three tribes Cornechiniscini tribe n., Pseudechiniscini tribe n. and Anthechiniscini tribe n.; and (c) subfamily Parechiniscinae subfam. n., with two tribes Parechiniscini tribe n. and Novechiniscini tribe n. Reliable biodiversity selection for tardigrades in broad phylogenies is proposed due to biased analyses performed up to now. We use our comprehensive molecular phylogeny to evaluate the evolution of claws in the clawless genus Apodibius and claw reduction across the Tardigrada tree of life. Evolutionary consequences are discussed. [ABSTRACT FROM AUTHOR]

The ecological implications of body size extend from the biology of individual organisms to ecosystem‐level processes. Measuring body mass for high numbers of invertebrates can be logistically challenging, making length–mass regressions useful for predicting body mass with minimal effort. However, standardized sets of scaling relationships covering a large range in body length, taxonomic groups, and multiple geographical regions are scarce. We collected 6,212 arthropods from 19 higher‐level taxa in both temperate and tropical locations to compile a comprehensive set of linear models relating live body mass to a range of predictor variables. We measured live weight (hereafter, body mass), body length and width of each individual and conducted linear regressions to predict body mass using body length, body width, taxonomic group, and geographic region. Additionally, we quantified prediction discrepancy when using parameters from arthropods of a different geographic region. Incorporating body width into taxon‐ and region‐specific length–mass regressions yielded the highest prediction accuracy for body mass. Using regression parameters from a different geographic region increased prediction discrepancy, causing over‐ or underestimation of body mass depending on geographical origin and whether body width was included. We present a comprehensive range of parameters for predicting arthropod body mass and provide guidance for selecting optimal scaling relationships. Given the importance of body mass for functional invertebrate ecology and the paucity of adequate regressions to predict arthropod body mass from different geographical regions, our study provides a long‐needed resource for quantifying live body mass in invertebrate ecology research. The ecological implications of body size extend from the biology of individual organisms to ecosystem‐level processes. Length–mass regressions are a powerful tool to predict body mass based on morphological traits of organisms. We present a comprehensive range of parameters for predicting arthropod body mass based on body length, width, taxonomy, and geographic origin. [ABSTRACT FROM AUTHOR]

Nowadays things are going smoother with secure lab funding and several students in the lab. GRAPH Felipe Aguilera was a BECAS CHILE-CONICYT recipient in 2010 to conduct his PhD studies in Australia. I started my lab in March 2018, and at that time I spent a considerable piece of time writing grants to secure lab funding. [Extracted from the article]

Summary: Non‐invasive imaging techniques like X‐ray computed tomography have become very popular in zoology, as they allow for simultaneous imaging of the internal and external morphology of organisms. Nevertheless, the effect of different staining approaches required for this method on samples lacking mineralized tissues, such as soft‐bodied invertebrates, remains understudied. Herein, we used synchrotron radiation‐based X‐ray micro‐computed tomography to compare the effects of commonly used contrasting approaches on onychophorans – soft‐bodied invertebrates important for studying animal evolution. Representatives of Euperipatoides rowelli were stained with osmium tetroxide (vapour or solution), ruthenium red, phosphotungstic acid, or iodine. Unstained specimens were imaged using both standard attenuation‐based and differential phase‐contrast setups to simulate analyses with museum material. Our comparative qualitative analyses of several tissue types demonstrate that osmium tetroxide provides the best overall tissue contrast in onychophorans, whereas the remaining staining agents rather favour the visualisation of specific tissues and/or structures. Quantitative analyses using signal‐to‐noise ratio measurements show that the level of image noise may vary according to the staining agent and scanning medium selected. Furthermore, box‐and‐whisker plots revealed substantial overlap in grey values among structures in all datasets, suggesting that a combination of semiautomatic and manual segmentation of structures is required for comprehensive 3D reconstructions of Onychophora, irrespective of the approach selected. Our results show that X‐ray micro‐computed tomography is a promising technique for studying onychophorans and, despite the benefits and disadvantages of different staining agents for specific tissues/structures, this method retrieves informative data that may eventually help address evolutionary questions long associated with Onychophora. [ABSTRACT FROM AUTHOR]

DNA metabarcoding holds great promise for the assessment of macroinvertebrates in stream ecosystems. However, few large-scale studies have compared the performance of DNA metabarcoding with that of routine morphological identification., We performed metabarcoding using four primer sets on macroinvertebrate samples from 18 stream sites across Finland. The samples were collected in 2013 and identified based on morphology as part of a Finnish stream monitoring program. Specimens were morphologically classified, following standardised protocols, to the lowest taxonomic level for which identification was feasible in the routine national monitoring., DNA metabarcoding identified more than twice the number of taxa than the morphology-based protocol, and also yielded a higher taxonomic resolution. For each sample, we detected more taxa by metabarcoding than by the morphological method, and all four primer sets exhibited comparably good performance. Sequence read abundance and the number of specimens per taxon (a proxy for biomass) were significantly correlated in each sample, although the adjusted R2 values were low. With a few exceptions, the ecological status assessment metrics calculated from morphological and DNA metabarcoding datasets were similar. Given the recent reduction in sequencing costs, metabarcoding is currently approximately as expensive as morphology-based identification., Using samples obtained in the field, we demonstrated that DNA metabarcoding can achieve comparable assessment results to current protocols relying on morphological identification. Thus, metabarcoding represents a feasible and reliable method to identify macroinvertebrates in stream bioassessment, and offers powerful advantage over morphological identification in providing identification for taxonomic groups that are unfeasible to identify in routine protocols. To unlock the full potential of DNA metabarcoding for ecosystem assessment, however, it will be necessary to address key problems with current laboratory protocols and reference databases. [ABSTRACT FROM AUTHOR]

GRAPH Andreas Wanninger was the coordinator of the EU Research Training Network MOLMORPH that united 5 European universities with research groups using EvoDevo, paleontology, morphology, and phylogeny to tackle various questions revolving around animal evolution. All this will most likely require change of labs and thus personal flexibility and willingness to move, especially as early career researcher, but it enhances your chances on the job market - in- and outside of academia. B I What was the biggest challenge in getting to your position?. [Extracted from the article]

The ichnogenus Tremichnus Brett was established for small round pits in echinoderm endoskeletons, principally crinoids. It is morphologically identical to Oichnus Bromley. It is significant that infestation of the echinoderm test is an integral part of any diagnosis of Tremichnus. This is an unacceptable ichnotaxobase; the diagnosis should only define morphology and, with reservation, substrate, such as unlithified (= soft), lithic or wood. From a recent revival of Tremichnus, Tremichnus paraboloides Brett is a junior homonym of Oichnus paraboloides Bromley; both share a similar morphology. Tremichnus puteolus Brett is more correctly referred to Lacrimichnus Santos et al. Tremichnus excavatus (Donovan and Jagt) could only be force-fitted into Tremichnus following a drastic revision of the original diagnosis and is here reassigned to Oichnus, as originally described. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Trait-based approaches are increasingly being used to test mechanisms underlying species assemblages and biotic interactions across a wide range of organisms including terrestrial arthropods and to investigate consequences for ecosystem processes. Such an approach relies on the standardized measurement of functional traits that can be applied across taxa and regions. Currently, however, unified methods of trait measurements are lacking for terrestrial arthropods and related macroinvertebrates (terrestrial invertebrates hereafter)., Here, we present a comprehensive review and detailed protocol for a set of 29 traits known to be sensitive to global stressors and to affect ecosystem processes and services. We give recommendations how to measure these traits under standardized conditions across various terrestrial invertebrate taxonomic groups., We provide considerations and approaches that apply to almost all traits described, such as the selection of species and individuals needed for the measurements, the importance of intraspecific trait variability, how many populations or communities to sample and over which spatial scales., The approaches outlined here provide a means to improve the reliability and predictive power of functional traits to explain community assembly, species diversity patterns and ecosystem processes and services within and across taxa and trophic levels, allowing comparison of studies and running meta-analyses across regions and ecosystems., This handbook is a crucial first step towards standardizing trait methodology across the most studied terrestrial invertebrate groups, and the protocols are aimed to balance general applicability and requirements for special cases or particular taxa. Therefore, we envision this handbook as a common platform to which researchers can further provide methodological input for additional special cases., A is available for this article. [ABSTRACT FROM AUTHOR]

We spend most of our lives inside homes, surrounded by arthropods that impact our property as pests and our health as disease vectors and producers of sensitizing allergens. Despite their relevance to human health and well-being, we know relatively little about the arthropods that exist in our homes and the factors structuring their diversity. As previous work has been limited in scale by the costs and time associated with collecting arthropods and the subsequent morphological identification, we used a DNA-based method for investigating the arthropod diversity in homes via high-throughput marker gene sequencing of home dust. Settled dust samples were collected by citizen scientists from both inside and outside more than 700 homes across the United States, yielding the first continental-scale estimates of arthropod diversity associated with our residences. We were able to document food webs and previously unknown geographic distributions of diverse arthropods - from allergen producers to invasive species and nuisance pests. Home characteristics, including the presence of basements, home occupants and surrounding land use, were more useful than climate parameters in predicting arthropod diversity in homes. These noninvasive, scalable tools and resultant findings not only provide the first continental-scale maps of household arthropod diversity, but our analyses also provide valuable baseline information on arthropod allergen exposures and the distributions of invasive pests inside homes. [ABSTRACT FROM AUTHOR]

Sensory organs in Annelida are very diverse and may be useful for assessments of morphological adaptation and character evolution. We used several methods to provide new insights into processes underlying the evolutionary radiation of anterior sensory organs in Sabellariidae. The presence and morphological diversity of the median organ ( MO) found in the group was reviewed in order to test its phylogenetic significance and possible relationships to the distribution and ecological traits of the lineages. To test the intraspecific phenotypic plasticity of the MO, molecular analyses were conducted that focused on mitochondrial and nuclear genes from populations of Idanthyrsus australiensis exhibiting variation in the morphology of the MO. We used an integrative microscopical study of the ontogeny of Sabellaria alveolata to describe the anterior sensory structures present in the larvae and the morphological changes occurring before, during, and after settlement. In larval stages, the palps and the dorsal hump ( DH) exhibit distinct innervation. The larval DH organ, which is likely to play a major role in chemoreception for settlement, is interpreted as being the incipient form of the adult MO. These results suggest that annelid sensory organs including the MO may be useful for phylogenetic and developmental investigations. [ABSTRACT FROM AUTHOR]

The genus Marphysa is widely collected for bait by recreational fishermen in Australia, and yet the number of species remains unresolved. A new species is described together with additional information on a previously described species. This study reveals that while species of Marphysa superficially resemble one another, detailed studies on the distribution of different types of chaetae along the body, together with molecular studies, uncover species which may co-occur. Correct identification is critical for management of these largely intertidal species. This study also highlights the increasing awareness of the presence of pseudo-cryptic species in polychaetes. [ABSTRACT FROM AUTHOR]

SEM analysis of trunk ornamentation on a compressed palaeoscolecid fossil from the Shipai fauna, Cambrian Series 2 and Stage 4 at Three Gorges, South China, allows a reassignment of the material to a new taxon, Sanxiascolex papillogyrus gen. et sp. nov. The preserved body is entirely annulated. Each annulus is ornamented by four rows of irregularly alternating plates and each plate bears numerous tubercles at the marginal region and a variable number (zero to six) of nodes at its central part. These features are unique among known palaeoscolecids. Comparative analyses with other compressed palaeoscolecid macrofossils and phosphatized material on the pattern of trunk ornamentation indicates that a detailed examination of the cuticle ornament weighs heavily in analyses of their taxonomic distinctions. A similar sclerite pattern to that of S. papillogyrus has been found in some phosphatized palaeoscolecid cuticle fragments as well as in isolated sclerites. The upper series of nodes and tubercles of these sclerites suggest an accretional mode of sclerite growth. The considerable variation in node number observed across the plates of S. papillogyrus demonstrates that phosphatic palaeoscolecid taxonomy based on relatively minor variations in the number of sclerite nodes should perhaps be reconsidered. As the origins of the phosphatized specimens are quite diverse, a large variety of isolated sclerites from the Early Palaeozoic may not reflect actual biodiversity. [ABSTRACT FROM AUTHOR]

The bivalved arthropod Branchiocaris? yunnanensis Hou, 1987 is redescribed on the basis of new fossil material from the early Cambrian Chengjiang biota, South China. In total, 81 specimens have been examined. The carapace comprises two identical valves, each valve are sub-circular in outline, ranging from 24 mm to 58 mm in length, and from 15 mm to 46 mm in height. The dorsal margin is straight and bears two short cardinal spines. The valve surface is either smooth or ornamented with polygonal reticular structures, which may result from different preservation conditions. Two morphotypes have been recognized based on the presence or absence of a subdorsal swelling of the valve, which is convex dorsolaterally and extends beyond the dorsal margin when it appears. Statistic and ontogenetic analyses show both morphotypes grow isometrically and have the same growth trajectory. Therefore, the two morphotypes are interpreted as dimorphism within the same species. Our results are helpful for investigating the taxonomy and ontogeny of arthropod fossils and suggest that dimorphism might be fairly common in these early arthropods. [ABSTRACT FROM AUTHOR]

Xiphosurids are an archaic group of aquatic chelicerate arthropods, generally known by the colloquial misnomer of 'horseshoe crabs'. Known from marine environments as far back as the early Ordovician, horseshoe crabs are generally considered 'living fossils' - descendants of a bradytelic lineage exhibiting little morphological or ecological variation throughout geological time. However, xiphosurids are known from freshwater sediments in the Palaeozoic and Mesozoic; furthermore, the contention that xiphosurids show little morphological variation has never been tested empirically. Attempts to test this are hampered by the lack of a modern phylogenetic framework with which to explore different evolutionary scenarios. Here, I present a phylogenetic analysis of Xiphosurida and explore patterns of morphospace and environmental occupation of the group throughout the Phanerozoic. Xiphosurids are shown to have invaded non-marine environments independently at least five times throughout their evolutionary history, twice resulting in the radiation of major clades - bellinurines and austrolimulids - that occupied novel regions of morphospace. These clades show a convergent ecological pattern of differentiation, speciation and subsequent extinction. Horseshoe crabs are shown to have a more dynamic and complex evolutionary history than previously supposed, with the extant species representing only a fraction of the group's past ecological and morphological diversity. [ABSTRACT FROM AUTHOR]

Bougainvillia triestina was described by Hartlaub in 1911 from specimens collected in the Gulf of Trieste (North Adriatic, Italy). Two years later, after re-examination of the same specimens, Neppi & Stiasny (1913) concluded that these were in fact juvenile medusae of Bougainvillia autumnalis (now synonymized with Bougainvillia muscus). Based on unique morphological traits and genetic analyses (16S rRNA, 18S rRNA, COI) of specimens of different stages recently collected in the shallow and enclosed coastal area of Ploče Harbour and Mali Ston Bay (South Adriatic, Croatia), we can confirm, 100 years after its first description, B. triestina as a valid, distinct species, clearly distinguishable from B. muscus (Allman 1863). Based on its occurrence in the Adriatic Sea, B. triestina seems to prefer productive coastal areas with a wide range of temperatures and salinities. Therefore, we expect that this species inhabits other coastal areas of the Mediterranean Sea as well as those of other seas and oceans. Given this, it is probable that in previous investigations some records of B. triestina were incorrectly attributed to B. muscus. [ABSTRACT FROM AUTHOR]

The family Anyphaenidae, also known as ghost spiders, includes a diverse array of nocturnal cursorial spiders that actively hunt on vegetation. The family is mostly distributed in the Americas and has been traditionally divided into three subfamilies. The mostly tropical and North American Anyphaeninae and the Amaurobioidinae, primarily distributed in southern South America, hold the bulk of the diversity, while the Malenellininae includes a single Chilean species. Here, we use a combined morphological and molecular approach to infer the relationships of the subfamily Amaurobioidinae and examine the delimitation of contentious genera. The morphological characters include both genitalic and somatic morphology, whereas molecular data include four markers, two mitochondrial ( COI, 16S) and two nuclear (28S, H3). All our analyses agree on the monophyly of Amaurobioidinae, Amaurobioidini, Gayennini, the genera Negayan, Amaurobioides, Josa, Araiya, Arachosia and Monapia, as well as the paraphyly of Anyphaeninae. The total evidence analysis supports the novel placement of Josa as the sister group of both tribes Amaurobioidini and Gayennini, most of the previously known intergeneric relationships within Gayennini, and a clade of Amaurobioidini with a projecting ocular area, including Aysenoides, Axyracrus, Amaurobioides and Aysenia. The sequence data solve the puzzling placement of Philisca puconensis, here transferred to Tomopisthes, and Tasata chiloensis, transferred to Oxysoma. The advantages of the total evidence phylogenetic approach and the evolution of the male copulatory organ are discussed. [ABSTRACT FROM AUTHOR]

We test the hypothesis that conochilid rotifers represent an independent family-level taxon within Superorder Gnesiotrocha, by analysing their phylogenetic position based on the 18S rDNA sequence of a large number of representatives of this taxon and its putative relatives. Both Bayesian and maximum likelihood analysis confirm a monophyletic clade of all gnesiotrochans with strong branch supports. Within Gnesiotrocha, Conochilidae form a strongly supported clade with representatives of all but some genera of Flosculariidae. These results refute Conochilidae as separate family-level taxon within Gnesiotrocha. This finding is also supported by a phylogenetic analysis using morphology, in particular new observations on trophi morphology. Conochilid rotifers are likely specialized Flosculariidae, which evolved to a planktonic lifestyle and reduction of coloniality within the group, in contrast to other Flosculariidae. Furthermore, our analysis reveals that two genera of Flosculariidae, Beachampia and Limnias, form a single, strongly supported clade in a sister-group relation to a clade consisting of representatives of Order Collothecacea. The present results, both regarding position of the conochild rotifers and of two genera of Flosculariidae, highlight the need for a more extensive analysis of relationships within Gnesiotrocha. [ABSTRACT FROM AUTHOR]

A new cryptostome bryozoan, Prophyllodictya simplex sp. nov., is described from the Nantzinkuan Formation ( Lower Ordovician, lower Tremadoc) of Liujiachang, central China. This antedates the previously oldest known bryozoan by several million years. Colony morphology and the phylogenetic position of Prophyllodictya within Cryptostomata are explored. Phylogenetic analysis suggests that Cryptostomata (except Prophyllodictya) can be divided into two major groups, and that Prophyllodictya occupies a basal position in the cryptostome tree, which accords with its simple morphology and antiquity. A close relationship is evident between bryozoans from the South China palaeoplate and those from Baltica. [ABSTRACT FROM AUTHOR]

Characterized by atypical frontalmost appendages, leanchoiliids are early arthropods whose phylogenetic placement has been much debated. Morphological interpretations have differed, some of which concern critical characters such as the number of eyes and head appendages, but methodological approaches also have diverged. Here, we describe a new leanchoiliid, Yawunik kootenayi gen. et sp. nov., based on 42 specimens from the newly discovered Marble Canyon locality of the Burgess Shale ( Kootenay National Park, British Columbia; middle Cambrian). This new morphotype demonstrates the presence of a four-segmented head in leanchoiliids, along with two small antero-median eyes in addition to lateral eyes. Yawunik is characterized by a 12-segmented trunk and a carinate, lanceolate telson adorned with minute spines. The 'great appendages' of the animal bear teeth on their two distal rami, which would have enhanced their ability to grasp prey. Attitudes of specimens, resulting from burial at multiple aspects of bedding, suggest the 'great appendages' were flexible and capable of antero-posterior rotation. We also discuss the nature of intersegmental tissues and filaments present within the 'great appendages'. Our phylogenetic analyses extend the monophyly of leanchoiliids to include Haikoucaris and Yohoia in a new clade, the Cheiromorpha nom. nov. (within Heptopodomera nom. nov.). Other nodes are poorly resolved unless implied weights are used, and in this case, the topology is critically sensitive to the coding prerogative of inapplicable states ( NAs). Both the traditional ' Arachnomorpha' hypothesis ( NAs as additional states) and the more recently favoured ' Artiopoda + Crustacea' ( NAs as uncertainties) were obtained using the same data set and outgroup. This result stresses, first, the historical importance of polarization over data content in scenarios of early arthropod evolution, and second, a pressing need to investigate the impacts of coding inapplicables, especially given the inflating effect of implied weights. [ABSTRACT FROM AUTHOR]

ABSTRACT The siphonophore Nanomia bijuga is a pelagic hydrozoan (Cnidaria) with complex morphological organization. Each siphonophore is made up of many asexually produced, genetically identical zooids that are functionally specialized and morphologically distinct. These zooids predominantly arise by budding in two growth zones, and are arranged in precise patterns. This study describes the cellular anatomy of several zooid types, the stem, and the gas-filled float, called the pneumatophore. The distribution of cellular morphologies across zooid types enhances our understanding of zooid function. The unique absorptive cells in the palpon, for example, indicate specialized intracellular digestive processing in this zooid type. Though cnidarians are usually thought of as mono-epithelial, we characterize at least two cellular populations in this species which are not connected to a basement membrane. This work provides a greater understanding of epithelial diversity within the cnidarians, and will be a foundation for future studies on N. bijuga, including functional assays and gene expression analyses. J. Exp. Zool. (Mol. Dev. Evol.) 324B:435-449, 2015. © 2015 The Authors. Journal of Experimental Zoology Part B: Molecular and Developmental Evolution Published by Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Onychophorans (velvet worms) are closely related to the arthropods, but their limb morphology represents a stage before arthropodization (i.e., the segmentation of the limbs). We investigated the expression of onychophoran homologs of genes that are involved in dorsoventral (DV) and proximo-distal (PD) limb patterning in arthropods. We find that the two onychophoran optomotorblind (omb) genes, omb-1 and omb-2, are both expressed in conserved patterns in the dorsal ectoderm of the limbs, including the onychophoran antennae (the frontal appendages). Surprisingly, the expression of decapentaplegic (dpp), which acts upstream of omb in Drosophila, is partially reversed in onychophoran limbs compared to its expression in arthropods. A conserved feature of dpp expression in arthropods and onychophorans, however, is the prominent expression of dpp in the tips of developing limbs, which, therefore, may represent the ancestral pattern. The expression patterns of wingless (wg) and H15 are very diverged in onychophorans. The wg gene is only expressed in the limb tips and the single H15 gene is expressed in a few dorsal limb cells, but not on the ventral side. The expression of wg and dpp at the limb tips is one of the three possible alternatives predicted by the topology model of arthropod limb patterning and is, thus, compatible with a conserved function of wg and dpp in the patterning of the PD axis. On the other hand, DV limb gene expression is less conserved, and the specification of ventral fate appears to involve neither wg nor H15 expression. [ABSTRACT FROM AUTHOR]

Adolf (Dolf) Seilacher, who died earlier this year at the age of 89, was a major figure in palaeontology on both sides of the Atlantic. His interests were diverse, including trace fossils, the processes involved in exceptional preservation, and the evolution of invertebrate morphology. But it is for his views on the nature of the extraordinary fossils of the Ediacaran that he is perhaps best known. His ideas-compelling and provocative-will continue to stimulate research for years to come, not least through the wide use of his terminology (e.g. Lagerstätten, morphodynamics, constructional morphology, vendobiont). [ABSTRACT FROM AUTHOR]

Annelids are a phylum of segmented bilaterian animals that have become important components of ecosystems spanning terrestrial realms to the deep sea. Annelids are remarkably diverse, possessing high taxonomic diversity and exceptional morphological disparity, and have evolved numerous feeding strategies and ecologies. Their interrelationships and evolution have been the source of much controversy over the past century with the composition of the annelid crown group, the relationship of major groups and the body plan of the ancestral annelid having undergone major recent revisions. There is a convincing body of molecular evidence that polychaetes form a paraphyletic grade and that clitellates are derived polychaetes. The earliest stem group annelids from Cambrian Lagerstätten are errant, epibenthic polychaetes, confirming that biramous parapodia, head appendages and diverse, simple chaetae are primitive for annelids. Current evidence from molecular clocks and the fossil record suggest that crown group annelids are a Late Cambrian - Ordovician radiation, with clitellates radiating in the Late Palaeozoic. Their body fossil record is largely confined to deposits showing exceptional preservation and is punctuated by the acquisition of hard parts in major groups. The discovery of an Ordovician fossil with soft tissues has shown that machaeridians are in fact a clade of crown polychaetes. They were in existence for more than 200 million years and possess unique calcitic dorsal armour, allowing their mode of life and phylogeny to be interpreted in the context of the annelid body plan. We identify a novel clade of machaeridians, the Cuniculepadida, which exhibit a series of adaptations for burrowing. [ABSTRACT FROM AUTHOR]

Coral planulae are induced to settle and metamorphose by contact with either crustose coralline algae or marine bacterial biofilms. Larvae of two coral species, Pocillopora damicornis and Montipora capitata, which respond to different metamorphic cues, were utilized to investigate the sensory mechanisms used to detect metamorphic cues. Because the aboral pole of the coral planula is the point of attachment to the substratum, we predicted that it is also the point of detection for cues. To determine where sensory cells for cues are localized along the body, individual larvae were transversely cut into oral and aboral portions at various levels along the oral-aboral axis, and exposed to settlement-inducing substrata. Aboral ends of M. capitata metamorphosed, while oral ends continued to swim. However, in larvae of P. damicornis, ¾ oral ends (i.e., lacking the aboral pole) were also able to metamorphose, indicating that the cells that detect cues may be distributed along the sides of the body. These cells do not correspond to FMRFamide-immunoreactive cells that are present throughout the body. Cesium ions induced both aboral and oral ends of larvae of both species to settle, suggesting that oral ends have not lost their capacity to metamorphose, despite lacking sensory cells to detect natural cues. To determine whether sensory cells in larvae of P. damicornis are restricted to one side of the body, swimming behavior over substrata was observed in larvae labeled with diI, a red fluorescent lipophilic membrane stain. The larvae were found to rotate around the oral-aboral axis, with their surface against the substratum, not favoring a particular side for detecting cues. While clarifying the regions of the larval body important for settlement and metamorphosis in coral planulae, we conclude that significant differences between coral species may be due to differences in the distribution of sensory structures in relation to different planular sizes. [ABSTRACT FROM AUTHOR]

Despite likely being the most diverse group within the Tricladida, the systematics of land planarians ( Geoplanidae) has received minor attention. The most species-rich ingroup, the subfamily Geoplaninae, is restricted to the Neotropics. The systematics of Geoplaninae remains uncertain. Unique features supporting the genera are scanty; moreover, parts of the known species have been poorly described, making comparative studies difficult. Likewise the evolutionary relationships among land planarians remain insufficiently understood. In the present study, a phylogenetic hypothesis for selected taxa of Geoplaninae based on the molecular data is presented and discussed in the light of morphological features. Our phylogenetic inference is based on the fragments of three nuclear regions (18 S, 28 S rDNA and EF-1α) and a mitochondrial marker (cytochrome oxidase I) for which we considered three optimality criteria (parsimony, maximum likelihood and Bayesian inference). Although our data provide little support for most basal nodes, our phylogenetic trees show a number of well-supported clades, unveiling morphologically homogeneous groups. According to these results, we propose to separate Geoplana into Barreirana (formerly considered a subgenus), Cratera gen. n., Imbira gen. n., Matuxia gen. n., Obama gen. n. and Paraba gen. n., emend the diagnoses of Barreirana, Geoplana, Notogynaphallia, Pasipha and Xerapoa and review the classification of the species within these genera. For Geoplana goetschi sensu Marcus, (1951), a new name is proposed. [ABSTRACT FROM AUTHOR]

The morphological variation of stromatoporoids, which are solitary organisms, is partitioned into its presumably genetic and environmental components. Potentially heritable, environmentally mediated and residual components of morphological variability were estimated in a test set containing Devonian stromatoporoids of the genus Gerronostromaria from southern Poland using analysis of variance. The taxonomic importance of traditional morphometric features is limited, because they are dominated by the intra-skeletal component of variance. Conventional metrics were therefore replaced by stereological and textural quantities. Both stereological and textural features are dominated by the inter-skeletal and inter-locality components of variation and thus may be valuable in taxonomic and environmental studies of stromatoporoids. Statistical analyses of these characters (principal component analysis and cluster analysis) were performed. Of 13 characters considered most useful in taxonomic studies, only five have been used previously in conventional species definitions. [ABSTRACT FROM AUTHOR]

Two character sets composed of continuous measurements and shape descriptors for mite harvestmen (Arachnida, Opiliones, Cyphophthalmi) were used to reconstruct the morphology of the cyphophthalmid ancestor and explore different methods for ancestral reconstruction as well as the influence of terminal sets and phylogenetic topologies. Characters common to both data sets were used to evaluate linear parsimony, averaging, maximum likelihood and Bayesian methods on seven different phylogenies found in earlier studies. Two methods-linear parsimony implemented in TNT and nested averaging-generated reconstructions that were (i) not predisposed to comprising simple averages of characters and (ii) in broad agreement with alternative methods commonly used. Of these two methods, linear parsimony yielded significantly similar reconstructions from two independent Cyphophthalmi data sets, and exhibited comparatively low ambiguity in the values of ancestral characters. Therefore complete sets of continuous characters were optimized using linear parsimony on trees found from 'total evidence' data sets. The resulting images of the ancestral Cyphophthalmi suggest it was a small animal with robust appendages and a lens-less eye, much like many of today's species, but not what might be expected from hypothetical reconstructions of Paleozoic vegetation debris, where Cyphophthalmi likely originated. © The Willi Hennig Society 2012 [ABSTRACT FROM AUTHOR]

Speciation by host shift is one of the explicit models of ecological speciation. A prerequisite of this model is the formation of host races (sympatric populations that show host-specific genetic structuring and phenotypes). Many members of the diverse marine bivalve superfamily Galeommatoidea have obligate commensal relationships with invertebrate hosts. Some species have the ability to occupy multiple host species, thereby providing potential opportunities to test for the formation of host races. The Northeast Pacific galeommatoidean Neaeromya rugifera attaches to two strikingly different hosts: the blue mud shrimp Upogebia pugettensis and the polychaete sea mouse Aphrodita spp. We tested if this host difference has resulted in the formation of host races using shell morphologies and genetic markers. We found that populations from different hosts differ significantly in shell morphology. However, based on mitochondrial makers, N. rugifera showed no distinct host-specific genetic structuring, indicating the existence of a panmictic population. We conclude that the host-specific morphologies these clams exhibit may reflect ecophenotypic plasticity rather than the existence of host races, but this needs to be corroborated with additional genetic data and larger sample sizes. The pronounced conchological variation within N. rugifera calls for further investigation of its taxonomic relationship with its poorly studied, but morphologically similar, sympatric congener Neaeromya compressa. [ABSTRACT FROM AUTHOR]

Ongoing discoveries of new rangeomorph fossils from the Ediacaran of Avalonia allow us to put forward a unified and approachable scheme for the description and phylogenetic analysis of frondose genera and their species. This scheme focuses upon the branching morphology of rangeomorph units. Our system has the advantage of being applicable at all visible scales of subdivision and is suitable for the study of isolated fragmentary specimens. The system is also free from hypothesis about biological affinity and avoids tectonically influenced features such as shape metrics. Using a set of twelve character states within this unified scheme, we here present emended diagnoses for Beothukis, Avalofractus, Bradgatia, Hapsidophyllas, Fractofusus, Trepassia and Charnia, together with a more extensive taxonomic treatment of the latter genus. For those forms that fall within the morphological spectrum between Trepassia and Beothukis, we introduce Vinlandia gen. nov. It is hoped that this scheme will provide a robust framework for future studies of rangeomorph ontogeny and evolution. [ABSTRACT FROM AUTHOR]

The article offers information on the 3rd International Congress of Invertebrate Morphology (ICIM3) held at the Humboldt University in Berlin, Germany from August 3-7, 2014. It mentions that conference focuses on research methods for invertebrate including light microscopy, confocal microscopy, and x-ray tomography.