Simple Morphology Research Articles

Cryptic diversity of small‐sized species of Phalacroma (Dinophysales, Dinophyceae) from Denmark Strait (Eastern Arctic Greenland)

SUMMARY Phalacroma currently comprises 69 species of mostly marine heterotrophic dinophysoids. With a round cell body and short sulcal and cingular lists, Phalacroma spp. have a simple morphology compared to other dinophysoid genera. Therefore, species identification is not always a trivial matter. A few Arctic species have been described and, with the exception of Ph. rotundatum, they are not only infrequently recorded but also occur in low cell abundances. Here, we studied a Lugol fixed sample from Denmark Strait. From this sample 13 cells with a Phalacroma‐like morphology were isolated under a stereo microscope, photo documented, and used for single‐cell PCR determination of nuclear‐encoded LSU rDNA sequences. The sequences fell in three groups defined by their ribotype. A single ribotype sequence representing each group was added to an alignment containing a diverse assemblage of dinophysoids and analyzed using Bayesian analysis and maximum likelihood. Based on comparative light microscopy one of the ribotypes (ribotype 1) was similar but not identical to Ph. ruudi and ribotype 2 could not be matched to a known species of Phalacroma. In the phylogeny both clustered with other species of Phalacroma including the type species. The morphology of ribotype 3 was similar but not identical to Ph. braarudii. In the phylogeny ribotype 3 clustered outside the core group of Phalacroma species. Hence, ribotype 3 was designated ‘Phalacroma’ sp. 3 and has to be described as a new genus pending additional data. This study has revealed the existence of cryptic species diversity within the Phalacroma morphotype boundary. Two additional Phalacroma species (Ph. apicatum and Ph. cf. argus) also clustered outside Phalacroma sensu stricto further emphasizing the presence of cryptic species within the genus. Future studies with a polyphasic approach are needed to better address the taxonomy of Phalacroma and Phalacroma‐like dinophysoids.

Electrode Materials with Highest Surface Area and Specific Capacitance Cannot Be the Only Deciding Factor for Applicability in Energy Storage Devices: Inference of Combined Life Cycle Assessment and Electrochemical Studies

Hierachical nanosheets of Co3O4 can deliver specific capacitance of ∼402 F g–1, which is 50% higher than that obtained using simpler disc shaped (∼230 F g–1) or conventional solid structures (∼150 F g–1). A simple question is then asked: should the particles showing other morphologies be discarded? As the electrode material is to be used in green or renewable energy technologies, the carbon footprint of each particle morphology was determined using the life cycle assessment (LCA) studies. The results led to inferences, which were strikingly different from those generally expected. It was seen that simpler morphologies, prepared using easier synthesis protocols, had five-times lower CO2 footprints than hierarchical morphology (nanosheets). The results become extremely critical for proposing their large scale industrial use. They clearly indicate that the choice of nanostructured metal oxides in energy storage devices will have to be relooked from the aspect of their own environmental impacts. Particles wit...

The Impact of Left Atrium Appendage Morphology on Stroke Risk Assessment in Atrial Fibrillation: A Computational Fluid Dynamics Study.

Atrial fibrillation (AF) carries out a 5-fold increase in stroke risk, related to embolization of thrombi clotting in left atrium (LA). Left atrial appendage (LAA) is the site with the highest blood stasis which causes thrombus formation. About 90 % of the intracardiac thrombi in patients with cardioembolic events originally develop in the LAA. Recent studies have been focused on the association between LAA anatomical features and stroke risk and provided conflicting results. Haemodynamic and fluid dynamic information on the LA and mostly on the LAA may improve stroke risk stratification. Therefore, the aim of this study was the design and development of a workflow to quantitatively define the influence of the LAA morphology on LA hemodynamics. Five 3D LA anatomical models, obtained from real clinical data, which were clearly different as regard to LAA morphology were used. For each LAA we identified and computed several parameters describing its geometry. Then, one LA chamber model was chosen and a framework was developed to connect the different LAAs belonging to the other four patients to this model. These new anatomical models represented the computational domain for the computational fluid dynamics (CFD) study; simulations of the hemodynamics within the LA and LAA were performed in order to evaluate the interplay of the LAA shape on the blood flow characteristics in AF condition. CFD simulations were carried out for five cardiac cycles. Blood velocity, vorticity, LAA orifice velocity, residence time computed in the five models were compared and correlated with LAA morphologies. Results showed that not only complex morphologies were characterized by low velocities, low vorticity and consequently could carry a higher thrombogenic risk; even qualitatively simple morphologies showed a thrombogenic risk equal, or even higher, than more complex auricles. CFD results supported the hypothesis that LAA geometric characteristics plays a key-role in defining thromboembolic risk. LAA geometric parameters could be considered, coupled with the morphological characteristics, for a comprehensive evaluation of the regional blood stasis. The proposed procedure might address the development of a tool for patient-specific stroke risk assessment and preventive treatment in AF patients, relying on morpho-functional defintion of each LAA type.

Zonation of Ca2+ transport and enzyme activity in the caeca of rainbow trout - a simple structure with complex functions.

Trout caeca are vermiform structures projecting from the anterior intestine of the gastrointestinal tract. Despite their simple gross morphology, these appendages are physically distinct along the anterior-posterior axis, and ultrastructural evidence suggests zonation of function within the structures. Individual caeca from three sections (anterior, middle and posterior) were removed from the intestine of freshwater rainbow trout and investigated for ion transport and enzyme activity. Ca2+ absorption appeared as a combination of active and passive movement, with Michaelis-Menten kinetics observable under symmetrical conditions, and was inhibited by several pharmacological agents (ouabain, La3+ and a calmodulin antagonist). There was a decrease in ion transport function from adjacent to the intestine (proximal) to the distal tip of each caecum, along with decreasing transport from anterior to posterior for the proximal portion alone. Feeding increased the JMax and KM for Ca2+ absorption within all sections, whereas ion-poor water (IPW) exposure further increased the JMax and KM for Ca2+ transport in the anterior and middle sections. Increased Na+/K+-ATPase (NKA) and citrate synthase (CS) activity rates paralleled trends seen in Ca2+ transport. Feeding in freshwater and IPW exposure increased the glycolytic capacity of the caeca via increased pyruvate kinase (PK) and decreased lactate dehydrogenase (LDH) activity, while amino acid metabolism increased with IPW exposure through increased glutamate dehydrogenase (GDH) activity. Overall, feeding and IPW exposure each altered ionoregulation within the caeca of freshwater rainbow trout in a zone-specific pattern, with the anterior and proximal portions of the caeca being most affected. Increased carbohydrate and protein metabolism fueled the increased ATP demand of NKA through CS.

Oikopleura dioica: An Emergent Chordate Model to Study the Impact of Gene Loss on the Evolution of the Mechanisms of Development.

The urochordate Oikopleura dioica is emerging as a nonclassical animal model in the field of evolutionary developmental biology (a.k.a. evo-devo) especially attractive for investigating the impact of gene loss on the evolution of mechanisms of development. This is because this organism fulfills the requirements of an animal model (i.e., has a simple and accessible morphology, a short generation time and life span, and affordable culture in the laboratory and amenable experimental manipulation), but also because O. dioica occupies a key phylogenetic position to understand the diversification and origin of our own phylum, the chordates. During its evolution, O. dioica genome has suffered a drastic process of compaction, becoming the smallest known chordate genome, a process that has been accompanied by exacerbating amount of gene losses. Interestingly, however, despite the extensive gene losses, including entire regulatory pathways essential for the embryonic development of other chordates, O. dioica retains the typical chordate body plan. This unexpected situation led to the formulation of the so-called inverse paradox of evo-devo, that is, when a genetic diversity is able to maintain a phenotypic unity. This chapter reviews the biological features of O. dioica as a model animal, along with the current data on the evolution of its genes and genome. We pay special attention to the numerous examples of gene losses that have taken place during the evolution of this unique animal model, which is helping us to understand to which the limits of evo-devo can be pushed off.

A new mammal from the Upper Cretaceous (Turonian–Campanian) Galula Formation, southwestern Tanzania

We here establish a new mammaliaform genus and species, Galulatherium jenkinsi (Mammalia), from the Upper Cretaceous Galula Formation in the Rukwa Rift Basin of southwestern Tanzania. This represents the first named taxon of a mammaliaform from the entire Late Cretaceous of continental Afro-Arabia, an interval of 34 million years. Preliminary study of the holotypic and only known specimen (a partial dentary) resulted in tentative assignation to the Gondwanatheria, a poorly known, enigmatic clade of Late Cretaceous-Paleogene Gondwanan mammals (Krause et al. 2003). The application of advanced imaging (mu CT) and visualization techniques permits a more detailed understanding of key anatomical features of the new taxon. It reveals that the lower dentition consisted of a large, procumbent lower incisor and four cheek teeth, all of which were evergrowing (hypselodont). Importantly, all of the teeth appear devoid of enamel. Comparisons conducted with a range of Mesozoic and selected Cenozoic mammaliaform groups document a number of features (e.g., columnar, enamel-less and evergrowing teeth, with relatively simple occlusal morphology) expressed in Galulatherium that are reminiscent of several distantly related groups, making taxonomic assignment difficult at this time. Herein we retain the provisional referral of Galulatherium (RRBP 02067) to Gondwanatheria; it is most similar to sudamericids such as Lavanify and Bharratherium from the Late Cretaceous of Madagascar and India, respectively, in exhibiting relatively simple, high-crowned, columnar cheek teeth. Other features (e.g., enamel-less dentition) are shared with disparate forms such as the Late Jurassic Fruitafossor and toothed xenarthrans (e.g., sloths), here attributed to convergence. Revised analyses of the depositional context for the holotype place it as having lived sometime between the late Turonian and latest Campanian (roughly 91-72 million years ago). This enhanced geochronological context helps to refine the palaeobiogeographical significance of Galulatherium among Cretaceous mammals in general and those from Gondwanan landmasses specifically.

Reactive nanotemplates for synthesis of highly efficient electrocatalysts: beyond simple morphology transfer.

Efficient electrocatalysts for energy conversion in general, and fuel cell operation and water electrolysis in particular, are pivotal for carbon-free hydrogen production. While the requirements of successful electrocatalysts include a high number density of catalytically active sites, high surface-to-volume ratio, inherently high catalytic activity, and robustness of the catalyst surface structure under harsh operating conditions, it is extremely difficult to synthesize nanocatalysts that could possess all these structural characteristics. Nanotemplate-mediated synthesis, namely, the coating or filling of a template with a desired material phase followed by the removal of the template, has captured the interest of researchers because of the ease of creating hollow-structured nanocatalysts with a high surface to volume ratio. Recent studies, however, have revealed that nanotemplates could be more than just passive supports because they greatly affect catalytic performance by creating an unusual synergy between the substrate and catalyst and by providing dopants to the actual catalyst phase owing to their reactive nature. In this review, we discuss the most notable recent advances in the nanotemplate-based synthesis of electrocatalysts as well as the unusual effects of nanotemplates on the performance of nanocatalysts. We also provide an outlook for this fledgling field so that future research efforts could be focused on the development of practically useful electrocatalysts that could shape the future of energy technologies.

Throwing light on an uncommon preservation of Blattodea from the Crato Formation (Araripe Basin, Cretaceous), Brazil

Fossilization results from several physical-chemical-geological processes. Original labile and non-bioclastic structures rarely survive throughout this process. In particular, the Crato Formation (Araripe Basin) is one of the most significant Cretaceous Konservat- Lagerstatten due to its well-preserved invertebrates, mainly three-dimensional insects. In general, Crato insects exhibit brown-orange color, constituted by goethite or hematite replacements. In this context, we used the scanning electron microscopy coupled to energy dispersive spectrometer and Raman spectroscopy to analyze Araripeblatta dornellesae, a 115 million-years-old fossil from Crato Formation, Araripe Basin. Our results show that a dark-color material rather than the brown-orange pattern preserve this specimen. The carbon is restricted to the fossil imprint, indicating some retention of the original organic remains. In addition, the presence of original organic components allowed to approach the biochemical aspects further than simple morphology, as well as to elucidate the taphonomical complexity involved in this preservation style.

Species delimitation methods reveal cryptic diversity in the Hypnea cornuta complex (Cystocloniaceae, Rhodophyta)

ABSTRACTThe simple and convergent morphologies of many red algae make these species difficult to identify using traditional morphological characters. Many cryptic species have been described in recent years based on molecular datasets, and this has led to the application of an integrative taxonomy approach in species delimitation. Here, we performed several species delimitation methods (mBGD, ABGD, SPN, PTP, GMYCs and GMYCm) based on two different loci (COI-5P and rbcL) in species of the Hypnea cornuta complex. These methods were combined with morphological and phylogenetic data, extensive sampling, analysis of topotype material, and historically relevant herbarium samples. Our findings demonstrate that the groups morphologically assigned to H. cornuta and H. stellulifera consist of five different cryptic species. H. cornuta is a polyphyletic taxon composed of three well-separated lineages, thus requiring sequencing of type or topotype specimens to determine which one is Hypnea cornuta sensu stricto. We have revealed that the distribution of H. stellulifera is limited to Asia, while the Brazilian specimens initially assigned to this species were clarified as a new endemic species: Hypnea cryptica sp. nov. Our results indicated that only an integrative approach combining several lines of evidence, including morphology, nomenclature history, molecular data, biogeography and ecology can correctly solve the taxonomic status of widely distributed cryptic species.

Analysis of immune response in the sea urchin larva.

Sea urchin larvae deploy a complex immune system in the context of relatively simple morphology. Several types of phagocytic or granular immune cells respond rapidly to microbes and microbial components within the body cavity. Many of these cells also respond to microbial disturbances in the gut lumen. In the course of immune response, hundreds of genes are up- and downregulated, many of which have homologs involved in immunity in other species. Thus, the larval sea urchin provides an experimentally advantageous model for investigating the response to immune challenge at the level of cell behavior and gene regulatory networks. Importantly, the morphological simplicity and optical clarity of these larvae allow studies to be carried out within the intact animal. Here, we outline techniques to probe and visualize the immune system of the feeding sea urchin larva, particularly for quantifying gene expression and cell migration as the animal responds to both pathogens and symbionts. Techniques addressed in this chapter include (1) exposure of larvae to microbes and microbial products in sea water and by blastocoelar microinjection, (2) time-lapse imaging of immune response, (3) isolation of culturable bacteria associated with feeding larvae, (4) quantification of larval associations with isolated bacterial strains and (5) preparation of secreted products from isolated bacteria for testing in larval culture.

Phylogenetic position of the parasitic nematode Trophomera (Nematoda, Benthimermithidae): A molecular analysis

Benthimermithid nematodes are parasites of invertebrates currently classified within their own order. Relationships between the Benthimermithida and other nematode orders, however, remain unclear due to their relatively simple morphology, their rarity, and paucity of molecular sequence data. Here, we combine molecular sequences obtained from Trophomera cf. marionensis in the Kermadec Trench with existing Trophomera sequences to determine the phylogenetic position of benthimermithids. Our SSU analyses showed Trophomera to be most closely-related to the order Plectida, subclass Chromadorea. Trophomera sequences formed a well-supported monophyletic clade placed within the Plectida, however relationships with other taxa within the order could not be resolved. Based on the result of these analyses, we propose that the family Benthimermithidae be moved to the order Plectida, however, future research on the classification of the family should focus on the benthimermithid genera Bathynema and Adenodelphis, for which no molecular sequences are yet available. We could not confirm a relationship between Trophomera and the family Camacolaimidae, which are both characterised by the presence of a stylet or stylet-like structure in the buccal cavity. Stylets are a common feature of parasitic nematodes, and its presence in a free-living benthimermithid ancestor perhaps similar to present-day camacolaimids could have facilitated a transition to a parasitic lifestyle. Our SSU phylogenetic analyses show that some features of benthimermithids, including the trophosome and a parasitic life cycle where the adults mate outside the host, have evolved independently in different groups of parasitic nematodes.

New record of organic-walled, morphologically distinct microfossils from the late Paleoproterozoic Changcheng Group in the Yanshan Range, North China

Eukaryotic life has likely existed since the late Paleoproterozoic, yet little is known about its early diversity and phylogenetic relationships. Organic-walled microfossils (OWMs) with conspicuous morphology provide a unique material to investigate the deep evolution of eukaryotic and prokaryotic microbial clades. Here we report a diverse assemblage of OWMs from the lower Changcheng Group (c. 1673–1638 Ma, Changzhougou and Chuanlinggou formations) in the Yanshan Range, North China, which consists of 15 species, including 2 that are newly described. The fossil assemblage is dominated by spheromorphs with less numerous process-bearing vesicles, as are colonial and filamentous forms. Among these, 6 morphologically complex taxa (Dictyosphaera, 2 species of Germinosphaera, Pterospermopsimorpha, Simia, and Valeria) are identified as unambiguous unicellular eukaryotes. Four species (Cucumiforma, Navifusa, Schizofusa and large Leiosphaeridia) with relatively simple morphology but having large size, thick wall, and some showing median-split excystment structures, are of probable eukaryotic affinity. However, various colonial microfossils could be either eukaryotes or prokaryotes. The new record of morphologically disparate OWMs represents one of the earliest occurrences of eukaryotes in both China and the world, and indicates that the eukaryotic life was already well established in the late Paleoproterozoic and was of moderate diversity, similar to that of the Mesoproterozoic.

2D photonic crystal nanodisk array as electron transport layer for highly efficient perovskite solar cells

Perovskite solar cells (PSCs) are currently exhibiting reproducible high efficiency; the manufacturing of low cost, scalable electron transport layers (ETLs) is becoming increasingly important. However, this remains a challenge for electron transport layers that exhibit excellent optical/electrical properties while being a thin film of simple morphology. Here we demonstrate the PSC of a 2D photonic crystal nanodisk (ND) array ETL that is compact, but greatly enhances light harvesting. The ND array is fabricated by nanosphere lithography using a monolayer of self-assembled polymer spheres as a physical mask. We fabricate ND arrays of various lattice constants simply by controlling the size of the polymer spheres. Optimal ND arrays exhibit strong forward scattering and optical confinement effects, greatly improving light harvesting in the perovskite layer. We also observe that the ND array improves charge transport by reducing contact resistance with the perovskite layer. ND array ETL PSCs reach 19% maximum power conversion efficiency, with low photocurrent-voltage hysteresis and stable photocurrent output.

The first record of Anancus (Mammalia, Proboscidea) in the late Miocene of Greece and reappraisal of the primitive anancines from Europe

ABSTRACTIn this article, we present the proboscideans from the late Miocene (Turolian) locality Chomateri, Greece, near the classical locality Pikermi. The material consists of juvenile teeth, whose morphological features, such as the dislocation of the half-loph(id)s and the resultant alternate arrangement of the successive loph(id)s (anancoidy), permit assignment to the tetralophodont gomphothere Anancus. However, the anancoidy is rather weak and the occlusal morphology simple, both regarded as primitive features within anancines. Reexamination of the late Miocene anancines from Europe reveals that they all share primitive molar features (weak anancoidy, simple morphology, thick enamel) with the material from Hohenwarth, Austria, showing further primitive skull features, such as the longer mandibular symphysis compared with other anancines. The proper name to refer to the late Miocene anancines from Europe is Anancus lehmanni (Gaziry, 1997), with type locality Dorn-Dürkheim 1 (Turolian; Germany). The presence of Anancus in Chomateri constitutes the first late Miocene record of the genus in Greece, and the first faunal element that clearly indicates that Chomateri postdates the classical Pikermi. Finally, we discuss the biostratigraphy and the biogeography of the late Miocene anancines of the Old World. Anancus originated possibly at ∼9.0–8.5 Ma in Asia and entered Europe during the second half of the Turolian, at ∼7.2 Ma (Tortonian-Messinian boundary). The arrival of Anancus in Europe coincides with a faunal turnover in both the eastern and western sectors of the European Mediterranean region, and in the southern Balkans in particular, with the decline of the ‘Pikermian’ large-mammal fauna.

Neighbor Diversity Regulates the Productivity of Coral Assemblages

Sustaining ecological functions as biodiversity changes will be a major challenge in the 21st century [1]. However, our understanding of the relationship between biodiversity and ecosystem function is still emerging on tropical coral reefs [2], where reef-building corals form highly productive assemblages [3, 4] and species respond in different ways to their neighbors [5] and their environment (e.g., water flow) [6]. Experimental coral communities were assembled to quantify the performance of coral colonies with and without neighbors and in the presence of conspecifics versus heterospecifics. Under higher flow, we identified a positive effect of coral species richness on primary productivity (gross and net photosynthesis) indicated by a 53% increase in productivity in multispecies assemblages (2-4 species) relative to monocultures. Productivity in monocultures was predicted by surface areas associated with different species morphologies. In contrast, multispecies assemblages maintained high levels of productivity even in the absence of the most productive species, reflecting non-additive effects of species richness on community functioning. Assemblage performances were regulated by positive and negative interactions between colonies, with many colonies performing better among heterospecific neighbors than in isolation (facilitation). Facilitation occurred primarily among flow-sensitive taxa with simple morphologies and did not occur under lower flow, suggesting that modifications to flow microclimates by corals generated beneficial, interspecific interactions. Our results show that competition and facilitation among neighbors may be important mechanisms regulating coral assemblage productivity in variable environments. Furthermore, shifts in the diversity and identity of neighbors can impair these interactions, with potentially widespread consequences for coral community functioning.

Reservoir Effects on Flood Peak Discharge at the Catchment Scale

AbstractThis paper proposes a method to easily quantify the attenuation due to a reservoir on downstream flood peak discharges, that is, to the downstream flood frequency curve. Using a parsimonious Instantaneous Unit Hydrograph‐based model, we show that the flood peak attenuation is mainly controlled by three system characteristics: (1) the reservoir position along the river channel, (2) the spillway dimensions, quantified by the reservoir storage coefficient; and (3) the storage capacity. These three system characteristics are quantified by three dimensionless numbers, which are derived analytically for an idealized catchment. The degree of flood peak attenuation increases for increasing storage capacity and spillway dimensions, in different ways depending on the reservoir position along the river channel. An optimal position exists, which maximizes the degree of flood peak attenuation, and is in general different from the outlet of the catchment. Interestingly, for large reservoirs with relatively small spillways, a range of quasi‐optimal positions exists. With the Instantaneous Unit Hydrograph‐based model, we also investigate how the duration of extreme rainfall relevant for determining the maximum flood peaks at the catchment outlet changes depending on the three system characteristics. Some of the assumptions of the method (i.e., catchment simple morphology and linearity of reservoir response) are relaxed in a real‐world example, which demonstrates that the synthetic results approximate well what would be obtained by a more realistic model.

Complex Left Atrial Appendage Morphology Is an Independent Risk Factor for Cryptogenic Ischemic Stroke.

Importance: Ischemic strokes pose a significant health burden. However, the etiology of between 20 and 40% of these events remains unknown. Left atrial appendage morphology may influence the occurrence of thromboembolic events.Design: A retrospective cross-sectional study was conducted to investigate the role of LAA morphology in patients with atrial fibrillation (AF) and cardioembolic-associated stroke and patients with cryptogenic stroke without atrial fibrillation. LAA morphology is classified into two groups: (1) simple (chicken-wing) vs. (2) complex (non-chicken wing) based on transesophageal echocardiography (TEE) findings. In addition to the LAA morphology, left atrial parameters, including orifice diameter, depth, emptying velocity, and filling velocity, were collected for both groups. Mathematical, computational models were constructed to investigate flow velocities in chicken-wing and non-chicken wing morphological patterns to assess LAA function further.Findings: TEE values for volume, size, emptying, and filling velocities were similar between simple and complex LAA morphology groups. Patients with cryptogenic stroke without coexisting AF were noted to have significantly higher rates of complex LAA morphology. Chicken-wing LAA morphology was associated with four-fold higher flow rate (kg/s) in computational simulations.Conclusions: Complex LAA morphology may be an independent contributing factor for cryptogenic strokes. Further studies are warranted to investigate the mechanism involved in LAA morphology and thromboembolic events.

Adult Learning and Language Simplification.

Languages spoken in larger populations are relatively simple. A possible explanation for this is that languages with a greater number of speakers tend to also be those with higher proportions of non‐native speakers, who may simplify language during learning. We assess this explanation for the negative correlation between population size and linguistic complexity in three experiments, using artificial language learning techniques to investigate both the simplifications made by individual adult learners and the potential for such simplifications to influence group‐level language characteristics. In Experiment 1, we show that individual adult learners trained on a morphologically complex miniature language simplify its morphology. In Experiment 2, we explore how these simplifications may then propagate through subsequent learning. We use the languages produced by the participants of Experiment 1 as the input for a second set of learners, manipulating (a) the proportion of their input which is simplified and (b) the number of speakers they receive their input from. We find, contrary to expectations, that mixing the input from multiple speakers nullifies the simplifications introduced by individuals in Experiment 1; simplifications at the individual level do not result in simplification of the population's language. In Experiment 3, we focus on language use as a mechanism for simplification, exploring the consequences of the interaction between individuals differing in their linguistic competence (as native and non‐native speakers might). We find that speakers who acquire a more complex language than their partner simplify their language during interaction. We ultimately conclude that adult learning can result in languages spoken by more people having simpler morphology, but that idiosyncratic simplifications by non‐natives do not offer a complete explanation in themselves; accommodation—by comparatively competent non‐natives to less competent speakers, or by native speakers to non‐natives—may be a key linking mechanism.

New data on the Miocene dormouse Simplomys García-Paredes, 2009 from the peri-alpin basins of Switzerland and Germany: palaeodiversity of a rare genus in Central Europe

Simplomys, a dormouse with a simple dental morphology compared to other glirids, shows a continuous evolution in Spain during the end of the Ramblian and up to the middle Aragonian, the stratigraphic frame considered in this work. In contrast, the record of the genus in Central Europe is reduced to a few localities spanning from the early to the middle Miocene. We review the record from the Burdigalian to Langhian equivalent to the deposition of the uppermost Upper Marine Molasse (OMM) to the lower part of the Upper Freshwater Molasse (OSM) and conclude the occurrence of three distinct species. The youngest species, Simplomys simplicidens, is recognised in Schonenberg (Germany, MN5) and Courrendlin-Sole (Switzerland; MN4). Material from a fissure filling near Glovelier (Switzerland, MN4) supplied the new species, Simplomys hugi, whereas the localities Petersbuch 2 and Erkersthofen 2 (both fissure fillings from Germany, MN4) contain species closely related to it. Finally, and pending further advances in the taxonomy of the Iberian Simplomys, the oldest population from the fissure filling of Schnaitheim (Germany; MN3) remains in open nomenclature (Simplomys sp.). The genus Simplomys has not been recorded eastwards from the Swabian and Franconian Jura Plateaus from Germany and its youngest occurrence in Schonenberg is correlated to the South German local scale OSM C+D, at around 15.5 Ma.

Shellfish import and hull fouling as vectors for new red algal introductions in the Venice Lagoon

Touristic and commercial shipping traffic, the import of fish products and aquaculture activities are the most important vectors for the introduction of non-indigenous species (NIS) in the Mediterranean Sea. In this context, the Venice Lagoon (North Adriatic Sea) is considered a hotspot of NIS introductions. Among macroalgae, identification of these alien taxa on the basis of morphological characters is difficult due to their simple morphology, phenotypic plasticity and the occurrence of morphologically overlapping species. Here we report three new introduced species for the Mediterranean Sea: Aglaothamnion halliae, Melanothamnus japonicus and Polysiphonia schneideri. The samples belong to different genera of the order Ceramiales (Rhodophyta) and were collected in six stations of the Venice Lagoon. Aglaothamnion halliae and Melanothamnus japonicus were probably introduced via shellfish products, in particular, with the American clam, Mercenaria mercenaria, and with the Japanese oyster, Magallana gigas, respectively. Polysiphonia schneideri, instead, appears to have been introduced from Spain via the Strait of Gibraltar as a fouling organism on ship hulls. The presence of closely related cryptic species in the Venice Lagoon, such as Aglaothamnion tenuissimum, Melanothamnus harveyi and Polysiphonia denudata, and the lack of diagnostic characters can lead to the underestimation of the biodiversity of these genera. For these reasons, we used DNA barcoding to discover and correctly identify these new introduced specimens.