Database Of Occurrences Research Articles

GlobalFungi, a global database of fungal occurrences from high-throughput-sequencing metabarcoding studies

Fungi are key players in vital ecosystem services, spanning carbon cycling, decomposition, symbiotic associations with cultivated and wild plants and pathogenicity. The high importance of fungi in ecosystem processes contrasts with the incompleteness of our understanding of the patterns of fungal biogeography and the environmental factors that drive those patterns. To reduce this gap of knowledge, we collected and validated data published on the composition of soil fungal communities in terrestrial environments including soil and plant-associated habitats and made them publicly accessible through a user interface at https://globalfungi.com. The GlobalFungi database contains over 600 million observations of fungal sequences across > 17 000 samples with geographical locations and additional metadata contained in 178 original studies with millions of unique nucleotide sequences (sequence variants) of the fungal internal transcribed spacers (ITS) 1 and 2 representing fungal species and genera. The study represents the most comprehensive atlas of global fungal distribution, and it is framed in such a way that third-party data addition is possible.

Changes to the Monitoring Trends in Burn Severity program mapping production procedures and data products

BackgroundThe Monitoring Trends in Burn Severity (MTBS) program has been providing the fire science community with large fire perimeter and burn severity data for the past 14 years. As of October 2019, 22 969 fires have been mapped by the MTBS program and are available on the MTBS website (https://www.mtbs.gov). These data have been widely used by researchers to examine a variety of fire and climate science topics. However, MTBS has undergone significant changes to its fire mapping methodology, the remotely sensed imagery used to map fires, and the subsequent fire occurrence, burned boundary, and severity databases. To gather a better understanding of these changes and the potential impacts that they may have on the user community, we examined the changes to the MTBS burn mapping protocols and whether remapped burned area boundary and severity products differ significantly from the original MTBS products.ResultsAs MTBS data have been used over the course of many years and for many disparate applications, users should be aware that the MTBS burned area and severity products have been actively reviewed and revised to benefit from more robust satellite image availability and to address any observed quality issues. In a sample of 123 remapped fires, we found no significant change in the burned area boundary products when compared to the original mapped fires; however, significant changes did exist in the distribution of unburned, low, and moderate burn severity pixels within the thematic product.ConclusionsAnalysis of these remapped fires provides a look into how the MTBS fire mapping methods have evolved over time. In the future, additional changes to the MTBS data record may impact data users’ downstream applications. The MTBS program has an established continuous improvement approach to the MTBS methodology and products, and subsequently encourages users to confirm that they are using the most recent data.

The latitudinal diversity gradient of tetrapods across the Permo-Triassic mass extinction and recovery interval.

The decline in species richness from the equator to the poles is referred to as the latitudinal diversity gradient (LDG). Higher equatorial diversity has been recognized for over 200 years, but the consistency of this pattern in deep time remains uncertain. Examination of spatial biodiversity patterns in the past across different global climate regimes and continental configurations can reveal how LDGs have varied over Earth history and potentially differentiate between suggested causal mechanisms. The Late Permian-Middle Triassic represents an ideal time interval for study, because it is characterized by large-scale volcanic episodes, extreme greenhouse temperatures and the most severe mass extinction event in Earth history. We examined terrestrial and marine tetrapod spatial biodiversity patterns using a database of global tetrapod occurrences. Terrestrial tetrapods exhibit a bimodal richness distribution throughout the Late Permian-Middle Triassic, with peaks in the northern low latitudes and southern mid-latitudes around 20-40° N and 60° S, respectively. Marine reptile fossils are known almost exclusively from the Northern Hemisphere in the Early and Middle Triassic, with highest diversity around 20° N. Reconstructed terrestrial LDGs contrast strongly with the generally unimodal gradients of today, potentially reflecting high global temperatures and prevailing Pangaean super-monsoonal climate system during the Permo-Triassic.

Fish Occurrence Database of the Family Aphaniidae

Fish Occurrence Database of the Family Aphaniidae

Formation binning: a new method for increased temporal resolution in regional studies, applied to the Late Cretaceous dinosaur fossil record of North America

AbstractThe advent of palaeontological occurrence databases has allowed for detailed reconstruction and analyses of species richness through deep time. While a substantial literature has evolved ensuring that taxa are fairly counted within and between different time periods, how time itself is divided has received less attention. Stage‐level or equal‐interval age bins have frequently been used for regional and global studies in vertebrate palaeontology. However, when assessing diversity at a regional scale, these resolutions can prove inappropriate with the available data. Herein, we propose a new method of binning geological time for regional studies that intrinsically incorporates the chronostratigraphic heterogeneity of different rock formations to generate unique stratigraphic bins. We use this method to investigate the diversity dynamics of dinosaurs from the Late Cretaceous of the Western Interior of North America prior to the Cretaceous–Palaeogene mass extinction. Increased resolution through formation binning pinpoints the Maastrichtian diversity decline to between 68 and 66 Ma, coinciding with the retreat of the Western Interior Seaway. Diversity curves are shown to exhibit volatile patterns using different binning methods, supporting claims that heterogeneous biases in this time‐frame affect the pre‐extinction palaeobiological record. We also show that the apparent high endemicity of dinosaurs in the Campanian is a result of non‐contemporaneous geological units within large time bins. This study helps to illustrate the utility of high‐resolution, regional studies to supplement our understanding of factors governing global diversity in deep time and ultimately how geology is inherently tied to our understanding of past changes in species richness.

Use of openly available occurrence data to generate biodiversity maps within the South African EEZ

Biodiversity maps are an important component of ecosystem-based management and conservation. In the past, biodiversity maps were largely generated using patchy occurrence data from a range of data sources. Currently, substantial species occurrence data are readily available for large parts of the world and are accessible programmatically. Considering both the observed and expected changes in species distributions, and hence biodiversity, in response to present and future climate change, it is important to utilise readily available species occurrence databases to generate temporal and spatial biodiversity maps. In this study biodiversity maps were generated for three generic functional groups within the exclusive economic zone of South Africa: zooplankton, fishes and benthos. This was achieved by stacking individual species-distribution maps. Freely available occurrence data from the Ocean Biogeographic Information System (OBIS) were accessed for this purpose. Ensemble species-distribution modelling, employing five widely used statistical methods, was used to generate species-distribution maps for each functional group. The resulting spatial patterns of biodiversity for the three functional groups were largely in agreement with known patterns. The results of this study highlight the value of open-source occurrence and environmental data to generate biodiversity maps that can potentially be used in future spatial prioritisation or planning for management of marine areas and in environmental-change studies.

Using distribution models to estimate blooms of phytosanitary cyanobacteria in Brazil

Abstract: The multiple uses of aquatic ecosystems by humankind and the continuous interference of their activities have contributed to the emergence of potentially toxic cyanobacteria blooms. Here, we firstly created a database of occurrences of cyanobacteria blooms in Brazil through a systematic review of the scientific literature available in online platforms (e.g. Web of Science, Capes Thesis Catalogue). Secondly, we carried out ecological niche models with occurrence data obtained from these studies to predict climatically suitable areas for blooms. We select 21 bioclimatic variables input environmental data. We used five modeling methods for the current climate scenario: (1) Maxent; (2) Support Vector Machines; (3) Random Forest; (4) Maximum Likelihood e (5) Gaussian. We found that the number of publications about bloom events was higher in 2009 with a decline in the years 2012, 2013 and 2017. Furthermore, the years with the higher records of blooms in freshwater environments were 2005, 2011 e 2014. These events occurring mainly in public supply reservoirs and are mostly of the genera Microcystis Lemmermann, 1907, Dolichospermum (Ralfs ex Bornet & Flahault) P.Wacklin, L.Hoffmann & J.Komárek, 2009 and Raphidiopsis F.E.Fritsch & F.Rich, 1929. Modeling the potential distribution of blooms, we found sampling gaps that should be targeting for future researches, especially in the Amazon biome. Overall, the models did not predict highly suitable areas in the /north of Brazil, while other regions were relatively well distributed with a higher number of occurrence records in the Southeast region.

Influence of Railway Control and Signaling Equipment on Reduction of Occurrences in the State Railway Network of Czech Republic

The paper develops the issue of the evaluation of investment projects in the area of the national railway infrastructure solved within the research project. The research projects is focused on the evaluation of benefits connected with the increasing of the safety and the reliability of the railway infrastructure due to the realization of projects including investments into managing and security equipment. The paper is focused on the identification of the relation between the change of the level of security on the railway and the change of the number of occurrences on the railway. The methodology of the research consists in the analysis of the database of occurrences obtained from the sources of the Railway Infrastructure Administration, which includes approximately 1 000 occurrences annually per last ten years (2009 – 2018). The database includes detailed information about registered occurrences. The output of the partial part of the research is the identification of the relation between specific occurrence and its cause and the level of the security in the place of the origin of the occurrence. The results of the research will be consequently used for the evaluation of benefits connected with the increasing of the safety and the reliability of the railway.

Abundance and distribution of the white shark in the Mediterranean Sea

AbstractConservation of apex predators is a key challenge both in marine and terrestrial ecosystems. The white shark is a rare but persistent inhabitant of the Mediterranean Sea and it is currently assessed as “critically endangered” in the region. However, the population trends and dynamics of this species in the area are still unknown. Little is known about white shark distribution, habitat use and population abundance trends, aspects that are critical for conservation and management. In this study, we built the most comprehensive database of white shark occurrence records in the region. We collected 773 different records from different sources and used them to characterize the spatial and temporal patterns of abundance of Mediterranean white sharks between 1860 and 2016. We analysed these data by using generalized additive models and used spatially disaggregated information on human population abundance as a proxy of observation effort. Our results suggest a complex trajectory of population change characterized by a historical increase and a more recent reduction (61%, range 58%–72%) since the second half of the 20th century. In particular, analyses reveal a 52% (range 37%–88%) to 96% (range 92%–100%) overall decline in different Mediterranean sectors and a contraction in spatial distribution. Here, we provide the first reconstruction of abundance trends and offer new hypotheses regarding the drivers of change of white sharks in the Mediterranean. Our approach can be broadly applied to data‐poor contexts to reconstruct change and inform the conservation of endangered top predators in the Mediterranean Sea and other intensely used marine regions.

DnB, the Database of Nymphalids in Brazil, with a Checklist for Standardized Species Lists

DnB (Database of nymphalids in Brazil) centralizes the state of the art of all Nymphalidae species lists ever reported in Brazil. Butterflies are diverse, ecologically relevant, charismatic, and are effective flagships and bioindicators for conservation. With about 850 described species in Brazil, Nymphalidae is the group with the most stable taxonomy among the three richest Neotropical butterfly families and are frequently used in several biological disciplines as a model system. This study was developed from the need of an up-to-date, curated, and throughout database of species occurrences, the first of its kind in this continental, heterogeneous, and highly diverse country. The data can be used as a starting point for several purposes, such as mapping the distribution of Brazilian nymphalids, producing regional species lists with information of their richness, estimating priority regions (due to species occurrence or lack of sampling) and niche modeling – see DnB tutorials. Using both coarse-grained and exhaustive search strategies, we compiled 489 studies (peer-reviewed or not), from which 357 had species lists and were thus catalogued in a user-friendly software. We provide a separate worksheet with 34 columns of additional information, to filter DnB by e.g. biome, urban sampling, collection method; or to assess the quality of studies. Descriptive analyses revealed, as commonly reported, sampling bias towards large urban centers and proximity to research institutions (Wallacean shortfall), as well as taxonomic (Linnaean) shortfall of biodiversity. Aiming to standardize the publication and peer-review of species lists, we suggest a protocol, or checklist, of all steps required to ensure the comparability and minimum quality of such publications. DnB is available at https://doi.org/10.5281/zenodo.2561408, with a translated version in Portuguese available at http://doi.org/10.5281/zenodo.2561417 and we aim to update and re-publish it every 10 years so we encourage authors to send corrections and new species lists, published in any media, to 2018dnb@gmail.com.

Biotic and abiotic factors driving the diversification dynamics of Crocodylia

AbstractSpecies diversity patterns are governed by complex interactions among biotic and abiotic factors over time and space, but are essentially the result of the diversification dynamics (differential speciation and extinction rates) over the long‐term evolutionary history of a clade. Previous studies have suggested that temporal variation in global temperature drove long‐term diversity changes in Crocodylia, a monophyletic group of large ectothermic organisms. We use a large database of crocodylian fossil occurrences (192 spp.) and body mass estimations, under a taxic approach, to characterize the global diversification dynamics of crocodylians since the Cretaceous, and their correlation with multiple biotic and abiotic factors in a Bayesian framework. The diversification dynamic of crocodylians, which appears to have originated in the Turonian (c. 92.5 Ma), is characterized by several phases with high extinction and speciation rates within a predominantly low long‐term mean rate. Our results reveal long‐term diversification dynamics of Crocodylia to be a highly complex process driven by a combination of biotic and abiotic factors which influenced the speciation and extinction rates in dissimilar ways. Higher crocodylian extinction rates are related to low body mass disparity, indicating selective extinctions of taxa at both ends of the body mass spectrum. Speciation rate slowdowns are noted when the diversity of the clade is high and the warm temperate climatic belt is reduced. Our finding supports the idea that temporal variations of body mass disparity, self‐diversity, and the warm climate belt size provided more direct mechanistic explanations for crocodylian diversification than do proxies of global temperature.

The Influence of New Surveillance Data on Predictive Species Distribution Modeling of Aedes aegypti and Aedes albopictus in the United States.

The recent emergence or reemergence of various vector-borne diseases makes the knowledge of disease vectors’ presence and distribution of paramount concern for protecting national human and animal health. While several studies have modeled Aedes aegypti or Aedes albopictus distributions in the past five years, studies at a large scale can miss the complexities that contribute to a species’ distribution. Many localities in the United States have lacked or had sporadic surveillance conducted for these two species. To address these gaps in the current knowledge of Ae. aegypti and Ae. albopictus distributions in the United States, surveillance was focused on areas in Texas at the margins of their known ranges and in localities that had little or no surveillance conducted in the past. This information was used with a global database of occurrence records to create a predictive model of these two species’ distributions in the United States. Additionally, the surveillance data from Texas was used to determine the influence of new data from the margins of a species’ known range on predicted species’ suitability maps. This information is critical in determining where to focus resources for the future and continued surveillance for these two species of medical concern.

Comparing methods for mapping global parasite diversity

AbstractAimParasites are a major component of global ecosystems, yet spatial variation in parasite diversity is poorly known, largely because their occurrence data are limited and thus difficult to interpret. Using a recently compiled database of parasite occurrences, we compare different models which we use to infer parasite geographic ranges and parasite species richness across the globe.InnovationTo date, most studies exploring spatial patterns of parasite diversity assumed, with little validation, that the geographic range of a parasite species can be represented by the collective geographic range of its host species. Our study compares this assumption with a suite of other methods to infer parasite distribution from parasite occurrence data (e.g., based on data density, ecoregions and climatic conditions). We highlight diversity hotspots identified by the various methods and compare the effects of sampling intensities in different regions, a crucial factor determining observed parasite diversity.Main conclusionsThe type of model used to infer parasite distributions affects estimates of both total species richness and spatial patterns of hotspots of parasite richness. Overall, the models based on reported occurrences share similar areas of high parasite richness that tend to be biased towards areas of high sampling effort. In contrast, the model based on host distributions showed hotspots of parasite diversity that are biased towards areas of high host species richness. Accounting for sampling effort could only help to reconcile the outcome from the different models in some regions. Further, the non‐saturated species accumulation curves even for the best studied regions of the world such as Europe and North America serve as a call for further sampling effort and development of effective analytic tools that can provide robust accounts of global parasite diversity.

Spatio-Temporal Distribution of Monarch Butterflies Along Their Migratory Route

Efforts to conserve the migratory phenomenon of monarch butterflies in eastern North America have increased since a 2013-2014 monitoring report documenting a historical population low at the Monarch Butterfly Biosphere Reserve in Mexico. Surprisingly, there have been few systematic attempts to develop predictive models of monarch butterfly distributions along their migratory route between Mexico and the United States and Canada. Here we produced monthly habitat suitability models for monarch butterflies along their migratory route to identify potential areas for resting, feeding, and reproduction of the population. We compiled a point occurrence database of monarch butterflies for Mexico, USA, and Canada, including georeferenced records from GBIF, the Naturalista platform in Mexico, Correo Real initiative, and the Mexican governmental monitoring network for the monarch butterfly. We produced monthly habitat suitability models (HSM), using the R language and environment for statistical computing, abiotic (WorldClim), edaphic, and topographic variables. A total of 95 HSM were produced for each month. June to September, corresponding to the reproduction months in North America showed the highest geographic extent with suitable habitats; April, corresponding to the reproduction of the first post-migration generation, showed the smallest area. September, October and November, correspond to the movement of the monarch butterflies southwards, showed typical recognized distribution of the phenomenon and the overwintering months. December to February showed the smallest geographic extent in habitat suitability. Edaphic variables ranked high in importance in HSM for 11 of 12 months, indicating the relevance of vegetation and floral resources in the monarch butterfly migration route. Identifying such regions contribute to establish concrete conservation programs accordingly, as reduction of the use of pesticides and herbicides, decrease in the speed of cars in roads, and planting species with high nectary value, among others.. Our study provides a first predictive spatio-temporal approximation of the monarch butterfly migratory route annual cycle..

Survey completeness of a global citizen‐science database of bird occurrence

Measuring the completeness of survey inventories created by citizen‐science initiatives can identify the strengths and shortfalls in our knowledge of where species occur geographically. Here, we use occurrence information from eBird to measure the survey completeness of the world's birds in this database at three temporal resolutions and four spatial resolutions across the annual cycle during the period 2002 to 2018. Approximately 84% of the earth's terrestrial surface contained bird occurrence information with the greatest concentrations occurring in North America, Europe, India, Australia and New Zealand. The largest regions with low levels of survey completeness were located in central South America, northern and central Africa, and northern Asia. Across spatial and temporal resolutions, survey completeness in regions with occurrence information was 55–74% on average, with the highest values occurring at coarser temporal and coarser spatial resolutions and during spring migration within temperate and boreal regions. Across spatial and temporal resolutions, survey completeness exceeded 90% within ca 4–14% of the earth's terrestrial surface. Survey completeness increased globally from 2002 to 2018 across all months of the year at a rate of ca 3% yr–1. The slowest gains occurred in Africa and in montane regions, and the most rapid gains occurred in India and in tropical forests after 2012. Thus, occurrence information from a global citizen‐science program for a charismatic and well‐studied taxon was geographically broad but contained heterogeneous patterns of survey completeness that were strongly influenced by temporal and especially spatial resolution. Our results identify regions where the application of additional effort would address current knowledge shortfalls, and regions where the maintenance of existing effort would benefit long‐term monitoring efforts. Our findings highlight the potential of citizen science initiatives to further our knowledge of where species occur across space and time, information whose applications under global change will likely increase.

A simple method for assessing the completeness of a geographic range size estimate

Measuring geographic range size is a fundamental part of ecology and conservation. Geographic range size is used as a criterion by the IUCN Red List of Threatened Species in estimating species extinction risk. Yet the geographic distributions of many threatened species are poorly documented, and it is often unclear whether a geographic range size estimate is complete. Here we use a large and near-exhaustive database of species occurrences to (i) estimate extent of occurrence (a measure of geographic range size routinely used in Red List assessments), and (ii) develop a method to assess whether our estimate for each species is complete. We use an extensive database of point locality records for 24 Himalayan Galliformes, a group of highly threatened bird species. We examine the chronological pattern of increase of geographic range size estimates and compare this accumulation curve with a null model generated by performing 1000 iterations for each species using the point locality information in random order. Using Generalised Estimation Equations (GEE) and Generalised Least Square (GLS), we show that estimates of geographic range size for most species has now asymptoted, and that the range size estimates have improved more rapidly over time than expected by chance, suggesting relatively efficient sampling over time. The approach used in this study can be used as a simple method for assessing the completeness of a geographic range size estimates for any taxon.

A latitudinal diversity gradient of shallow-water gorgonians (Cnidaria: Octocorallia: Alcyonacea) along the Tropical Eastern Pacific Ocean: testing for underlying mechanisms

One of the most pervasive patterns leading the distribution of life on Earth is the latitudinal diversity gradient (LDG). Considering its generality, understanding its main causes is critical to predicting climatically driven biodiversity loss. Here, we analyzed the LDG pattern in gorgonians (Octocorallia: Alcyonacea) in the Tropical Eastern Pacific Ocean (TEP), where they form a widespread, species-rich, and ecologically important group of marine benthic organisms. We compiled a database of the geographic occurrence of shallow-water ( 60 spp., declining toward the north and south. The gorgonians exhibit an increase of their distribution ranges at higher latitudes, supporting predictions of Rapoport’s effect, an effect rarely found in TEP marine faunas. This pattern is likely the result of a decrease of gorgonian temperature tolerances at lower latitudes. We highlight the existence of at least four gorgonian assemblages within the TEP exhibiting distinctive temperature adaptations, and a strong change in species composition with latitude. Our results indicate that sea temperature is an important factor shaping the distribution of gorgonians in the TEP, as in several other marine taxa.

Global biogeographical regions of freshwater fish species

AbstractAimTo define the major biogeographical regions and transition zones for freshwater fish species.TaxonStrictly freshwater species of actinopterygian fish (i.e. excluding marine and amphidromous fish families).MethodsWe based our bioregionalization on a global database of freshwater fish species occurrences in drainage basins, which, after filtering, includes 11,295 species in 2,581 basins. On the basis of this dataset, we generated a bipartite (basin‐species) network upon which we applied a hierarchical clustering algorithm (the Map Equation) to detect regions. We tested the robustness of regions with a sensitivity analysis. We identified transition zones between major regions with the participation coefficient, indicating the degree to which a basin has species from multiple regions.ResultsOur bioregionalization scheme showed two major supercontinental regions (Old World and New World, 50% species of the world and 99.96% endemics each). Nested within these two supercontinental regions lie six major regions (Nearctic, Neotropical, Palearctic, Ethiopian, Sino‐Oriental and Australian) with extremely high degrees of endemism (above 96% except for the Palearctic). Transition zones between regions were of limited extent compared to other groups of organisms. We identified numerous subregions with high diversity and endemism in tropical areas (e.g. Neotropical), and a few large subregions with low diversity and endemism at high latitudes (e.g. Palearctic).Main conclusionsOur results suggest that regions of freshwater fish species were shaped by events of vicariance and geodispersal which were similar to other groups, but with freshwater‐specific processes of isolation that led to extremely high degrees of endemism (far exceeding endemism rates of other continental vertebrates), specific boundary locations and limited extents of transition zones. The identified bioregions and transition zones of freshwater fish species reflect the strong isolation of freshwater fish faunas for the past 10–20 million years. The extremely high endemism and diversity of freshwater fish fauna raises many questions about the biogeographical consequences of current introductions and extinctions.

Hydrate occurrence in Europe: A review of available evidence

Abstract Large national programs in the United States and several Asian countries have defined and characterised their marine methane hydrate occurrences in some detail, but European hydrate occurrence has received less attention. The European Union-funded project “Marine gas hydrate – an indigenous resource of natural gas for Europe” (MIGRATE) aimed to determine the European potential inventory of exploitable gas hydrate, to assess current technologies for their production, and to evaluate the associated risks. We present a synthesis of results from a MIGRATE working group that focused on the definition and assessment of hydrate in Europe. Our review includes the western and eastern margins of Greenland, the Barents Sea and onshore and offshore Svalbard, the Atlantic margin of Europe, extending south to the northwestern margin of Morocco, the Mediterranean Sea, the Sea of Marmara, and the western and southern margins of the Black Sea. We have not attempted to cover the high Arctic, the Russian, Ukrainian and Georgian sectors of the Black Sea, or overseas territories of European nations. Following a formalised process, we defined a range of indicators of hydrate presence based on geophysical, geochemical and geological data. Our study was framed by the constraint of the hydrate stability field in European seas. Direct hydrate indicators included sampling of hydrate; the presence of bottom simulating reflectors in seismic reflection profiles; gas seepage into the ocean; and chlorinity anomalies in sediment cores. Indirect indicators included geophysical survey evidence for seismic velocity and/or resistivity anomalies, seismic reflectivity anomalies or subsurface gas escape structures; various seabed features associated with gas escape, and the presence of an underlying conventional petroleum system. We used these indicators to develop a database of hydrate occurrence across Europe. We identified a series of regions where there is substantial evidence for hydrate occurrence (some areas offshore Greenland, offshore west Svalbard, the Barents Sea, the mid-Norwegian margin, the Gulf of Cadiz, parts of the eastern Mediterranean, the Sea of Marmara and the Black Sea) and regions where the evidence is more tenuous (other areas offshore Greenland and of the eastern Mediterranean, onshore Svalbard, offshore Ireland and offshore northwest Iberia). We provide an overview of the evidence for hydrate occurrence in each of these regions. We conclude that around Europe, areas with strong evidence for the presence of hydrate commonly coincide with conventional thermogenic hydrocarbon provinces.

Towards a barnacle tree of life: integrating diverse phylogenetic efforts into a comprehensive hypothesis of thecostracan evolution.

Barnacles and their allies (Thecostraca) are a biologically diverse, monophyletic crustacean group, which includes both intensely studied taxa, such as the acorn and stalked barnacles, as well as cryptic taxa, for example, Facetotecta. Recent efforts have clarified phylogenetic relationships in many different parts of the barnacle tree, but the outcomes of these phylogenetic studies have not yet been combined into a single hypothesis for all barnacles. In the present study, we applied a new “synthesis” tree approach to estimate the first working Barnacle Tree of Life. Using this approach, we integrated phylogenetic hypotheses from 27 studies, which did not necessarily include the same taxa or used the same characters, with hierarchical taxonomic information for all recognized species. This first synthesis tree contains 2,070 barnacle species and subspecies, including 239 barnacle species with phylogenetic information and 198 undescribed or unidentified species. The tree had 442 bifurcating nodes, indicating that 79.3% of all nodes are still unresolved. We found that the acorn and stalked barnacles, the Thoracica, and the parasitic Rhizocephala have the largest amount of published phylogenetic information. About half of the thecostracan families for which phylogenetic information was available were polyphyletic. We queried publicly available geographic occurrence databases for the group, gaining a sense of geographic gaps and hotspots in our phylogenetic knowledge. Phylogenetic information is especially lacking for deep sea and Arctic taxa, but even coastal species are not fully incorporated into phylogenetic studies.