Recent Submissions

  • Novel molecular approach to define pest species status and tritrophic interactions from historical Bemisia specimens

    Tay, WT; Elfekih, S; Polaszek, Andrew; Court, LN; Evans, GA; Gordon, KHJ; De Barro, PJ (Nature Research, 2017-03-27)
    Museum specimens represent valuable genomic resources for understanding host-endosymbiont/parasitoid evolutionary relationships, resolving species complexes and nomenclatural problems. However, museum collections suffer DNA degradation, making them challenging for molecular-based studies. Here, the mitogenomes of a single 1912 Sri Lankan Bemisia emiliae cotype puparium, and of a 1942 Japanese Bemisia puparium are characterised using a Next-Generation Sequencing approach. Whiteflies are small sap-sucking insects including B. tabaci pest species complex. Bemisia emiliae’s draft mitogenome showed a high degree of homology with published B. tabaci mitogenomes, and exhibited 98–100% partial mitochondrial DNA Cytochrome Oxidase I (mtCOI) gene identity with the B. tabaci species known as Asia II-7. The partial mtCOI gene of the Japanese specimen shared 99% sequence identity with the Bemisia ‘JpL’ genetic group. Metagenomic analysis identified bacterial sequences in both Bemisia specimens, while hymenopteran sequences were also identified in the Japanese Bemisia puparium, including complete mtCOI and rRNA genes, and various partial mtDNA genes. At 88–90% mtCOI sequence identity to Aphelinidae wasps, we concluded that the 1942 Bemisia nymph was parasitized by an Eretmocerus parasitoid wasp. Our approach enables the characterisation of genomes and associated metagenomic communities of museum specimens using 1.5 ng gDNA, and to infer historical tritrophic relationships in Bemisia whiteflies.
  • Professional fossil preparators at the British Museum (Natural History), 1843-1990*

    Graham, M; Reichenbach, H (Edinburgh University Press, 2019-10-01)
    Since the inception of the British Museum (Natural History) in 1881 (now the Natural History Museum, London), the collection, development and mounting of fossils for scientific study and public exhibition have been undertaken by fossil preparators. Originally known as masons, because of their rock-working skills, their roles expanded in the late nineteenth and early twentieth centuries, when, at the forefront of the developing science of palaeontology, the Museum was actively obtaining fossil material from the UK and abroad to build the collections. As greater numbers of more impressive specimens were put on public display, these preparators developed new and better methods to recover and transport fossils from the field, and technical improvements, in the form of powered tools, enabled more detailed mechanical preparation to be undertaken. A recurring theme in the history of palaeontological preparation has been that sons often followed in their fathers’ footsteps in earth sciences. William and Thomas Davies, Caleb and Frank Barlow, and Louis and Robert Parsons were all father-and-son geologists and preparators.
  • A Diverse Array of Fluvial Depositional Systems in Arabia Terra: Evidence for mid-Noachian to Early Hesperian Rivers on Mars

    Davis, Joel; Gupta, S; Balme, M; M. Grindrod, P; Fawdon, P; Dickeson, ZI; Williams, RME (Wiley, 2019-07-22)
    Branching to sinuous ridges systems, hundreds of kilometers in length and comprising layered strata, are present across much of Arabia Terra, Mars. These ridges are interpreted as depositional fluvial channels, now preserved as inverted topography. Here we use high‐resolution image and topographic data sets to investigate the morphology of these depositional systems and show key examples of their relationships to associated fluvial landforms. The inverted channel systems likely comprise indurated conglomerate, sandstone, and mudstone bodies, which form a multistory channel stratigraphy. The channel systems intersect local basins and indurated sedimentary mounds, which we interpret as paleolake deposits. Some inverted channels are located within erosional valley networks, which have regional and local catchments. Inverted channels are typically found in downslope sections of valley networks, sometimes at the margins of basins, and numerous different transition morphologies are observed. These relationships indicate a complex history of erosion and deposition, possibly controlled by changes in water or sediment flux, or base‐level variation. Other inverted channel systems have no clear preserved catchment, likely lost due to regional resurfacing of upland areas. Sediment may have been transported through Arabia Terra toward the dichotomy and stored in local and regional‐scale basins. Regional stratigraphic relations suggest these systems were active between the mid‐Noachian and early Hesperian. The morphology of these systems is supportive of an early Mars climate, which was characterized by prolonged precipitation and runoff.
  • Reduction of eyes in last-instar beetle larvae: a special observation in Trictenotomidae, based on Trictenotoma formosana Kriesche, 1919

    Telnov, D; Hu, F-S; Pollock, DA; Lin, Z-R (2019-10-03)
    Recently, Lin & Hu (2018, 2019) unraveled the biology of Trictenotoma formosana Kriesche, 1919. For the first time since Gahan (1908) there is fresh immature stages material available for Trictenotomidae.
  • Synopsis of the pelidnotine scarabs (Coleoptera, Scarabaeidae, Rutelinae, Rutelini) and annotated catalog of the species and subspecies

    Moore, MR; Jameson, ML; Garner, BH; Audibert, C; Smith, ABT; Seidel, M (Pensoft, 2017-04-06)
    The pelidnotine scarabs (Scarabaeidae: Rutelinae: Rutelini) are a speciose, paraphyletic assemblage of beetles that includes spectacular metallic species (“jewel scarabs”) as well as species that are ecologically important as herbivores, pollinators, and bioindicators. These beetles suffer from a complicated nomenclatural history, due primarily to 20th century taxonomic and nomenclatural errors. We review the taxonomic history of the pelidnotine scarabs, present a provisional key to genera with overviews of all genera, and synthesize a catalog of all taxa with synonyms, distributional data, type specimen information, and 107 images of exemplar species. As a result of our research, the pelidnotine leaf chafers (a paraphyletic group) include 27 (26 extant and 1 extinct) genera and 420 valid species and subspecies (419 extant and 1 extinct). Our research makes biodiversity research on this group tractable and accessible, thus setting the stage for future studies that address evolutionary and ecological trends. Based on our research, 1 new species is described, 1 new generic synonym and 12 new species synonyms are proposed, 11 new lectotypes and 1 new neotype are designated, many new or revised nomenclatural combinations, and many unavailable names are presented.

    Almeida, NV; Schofield, PF; Geraki, K; Russell, Sara (Lunar and Planetary Institute, 2019-08)
  • Factors affecting consistency and accuracy in identifying modern macroperforate planktonic foraminifera

    Fenton, IS; Baranowski, U; Boscolo-Galazzo, F; Cheales, H; Fox, L; King, DJ; Larkin, C; Latas, M; Liebrand, D; Miller, CG; et al. (The Micropalaeontological Society, 2018-09-25)
    Planktonic foraminifera are widely used in biostratigraphic, palaeoceanographic and evolutionary studies, but the strength of many study conclusions could be weakened if taxonomic identifications are not reproducible by different workers. In this study, to assess the relative importance of a range of possible reasons for among-worker disagreement in identification, 100 specimens of 26 species of macroperforate planktonic foraminifera were selected from a core-top site in the subtropical Pacific Ocean. Twenty-three scientists at different career stages – including some with only a few days experience of planktonic foraminifera – were asked to identify each specimen to species level, and to indicate their confidence in each identification. The participants were provided with a species list and had access to additional reference materials. We use generalised linear mixed-effects models to test the relevance of three sets of factors in identification accuracy: participant-level characteristics (including experience), species-level characteristics (including a participant's knowledge of the species) and specimen-level characteristics (size, confidence in identification). The 19 less experienced scientists achieve a median accuracy of 57 %, which rises to 75 % for specimens they are confident in. For the 4 most experienced participants, overall accuracy is 79 %, rising to 93 % when they are confident. To obtain maximum comparability and ease of analysis, everyone used a standard microscope with only 35× magnification, and each specimen was studied in isolation. Consequently, these data provide a lower limit for an estimate of consistency. Importantly, participants could largely predict whether their identifications were correct or incorrect: their own assessments of specimen-level confidence and of their previous knowledge of species concepts were the strongest predictors of accuracy.
  • Extensive sampling and thorough taxonomic assessment of Afrotropical Rhyssinae (Hymenoptera, Ichneumonidae) reveals two new species and demonstrates the limitations of previous sampling efforts

    Hopkins, T; Roininen, H; van Noort, S; Broad, G; Kaunisto, K; Sääksjärvi, IE (Pensoft Publishers, 2019-10-07)
    Tropical forest invertebrates, such as the parasitoid wasp family Ichneumonidae, are poorly known. This work reports some of the first results of an extensive survey implemented in Kibale National Park, Uganda. A total of 456 individuals was caught of the subfamily Rhyssinae Morley, 1913, which in the Afrotropical region was previously known from only 30 specimens. Here, the six species found at the site are described and the Afrotropical Rhyssinae are reviewed. Two new species, Epirhyssa johanna Hopkins, sp. nov. and E. quagga sp. nov., are described and a key, diagnostic characters, and descriptions for all 13 known Afrotropical species are provided, including the first description of the male of Epirhyssa overlaeti Seyrig, 1937. Epirhyssa gavinbroadi Rousse & van Noort, 2014, syn. nov. is proposed to be a synonym of E. uelensis Benoit, 1951. Extensive sampling with Malaise traps gave an unprecedented sample size, and the method is recommended for other poorly known tropical areas.
  • Phylogenomics resolves major relationships and reveals significant diversification rate shifts in the evolution of silk moths and relatives

    Hamilton, CA; St Laurent, RA; Dexter, K; Kitching, I; Breinholt, JW; Zwick, A; Timmermans, MJTN; Barber, JR; Kawahara, AY (BioMed Central, 2019-09-18)
    Background: Silkmoths and their relatives constitute the ecologically and taxonomically diverse superfamily Bombycoidea, which includes some of the most charismatic species of Lepidoptera. Despite displaying spectacular forms and diverse ecological traits, relatively little attention has been given to understanding their evolution and drivers of their diversity. To begin to address this problem, we created a new Bombycoidea-specific Anchored Hybrid Enrichment (AHE) probe set and sampled up to 571 loci for 117 taxa across all major lineages of the Bombycoidea, with a newly developed DNA extraction protocol that allows Lepidoptera specimens to be readily sequenced from pinned natural history collections. Results: The well-supported tree was overall consistent with prior morphological and molecular studies, although some taxa were misplaced. The bombycid Arotros Schaus was formally transferred to Apatelodidae. We identified important evolutionary patterns (e.g., morphology, biogeography, and differences in speciation and extinction), and our analysis of diversification rates highlights the stark increases that exist within the Sphingidae (hawkmoths) and Saturniidae (wild silkmoths). Conclusions: Our study establishes a backbone for future evolutionary, comparative, and taxonomic studies of Bombycoidea. We postulate that the rate shifts identified are due to the well-documented bat-moth “arms race”. Our research highlights the flexibility of AHE to generate genomic data from a wide range of museum specimens, both age and preservation method, and will allow researchers to tap into the wealth of biological data residing in natural history collections around the globe.
  • International Code of Nomenclature for algae, fungi, and plants (Shenzhen Code) adopted by the Nineteenth International Botanical Congress Shenzhen, China, July 2017.

    Turland, NJ; Wiersema, JH; Barrie, FR; Greuter, W; Hawksworth, DL; Herendeen, PS; Knapp, S; Kusber, W-H; Li, D-Z; Marhold, K; et al. (Koeltz Botanical BooksGlahutten, Germany, 2018-06-26)
    The rules that govern the scientific naming of algae, fungi, and plants are revised at the Nomenclature Section of an International Botanical Congress (IBC). This edition of the International Code of Nomenclature for algae, fungi, and plants embodies the decisions of the XIX IBC, which took place in Shenzhen, China in July, 2017. This Shenzhen Code supersedes the Melbourne Code (McNeill & al. in Regnum Veg. 154. 2012), published six years ago after the XVIII IBC in Melbourne, Australia, and like its five predecessors, it is written entirely in (British) English. The Melbourne Code was translated into Chinese, French, Italian, Japanese, Korean, Portuguese, Spanish, and Turkish; it is anticipated that the Shenzhen Code, too, will become available in several languages. In questions about the meaning of provisions in translated editions of this Code, the English edition is definitive.
  • Nomenclatural notes on Anthicidae and Pyrochroidae (Coleoptera). 6

    Telnov, Dmitry (Baltijas Koleopterologijas Instituts/Baltic Institute of Coleopterology, 2018-12-23)
    Five new combinations, three new synonyms and two new statuses for the Anthicidae are proposed. New distributional data or corrections are provided on 65 taxa of Pyrochroidae and Anthicidae. Eighteen new species and subspecies are described: Anthelephila panayensis sp. nov., Anthicus (s. str.) chitwanus sp. nov., A. (s. str.) lepcha sp. nov., A. (s. str.) vicinor sp. nov., Aulacoderus muehlei sp. nov., Clavicomus garze sp. nov., C. kham sp. nov., Cyclodinus phragmiteticola sp. nov., Macratria dotyali sp. nov., M. kopetzi sp. nov., M. leprieuri gasconica ssp. nov., Macratriomima casuarius sp. nov., M. chandleri sp. nov., Notoxus reuteri sp. nov., Rimaderus bonadonai sp. nov., R. sahyadri sp. nov., Stenidius obliquesetosus sp. nov., and Tomoderus schmidti sp. nov. Additional description is given for Anthelephila kresli Kejval, 2007 and Yunnanomonticola Telnov, 2002.
  • Descriptions of two new Australian genera of Anthicidae (Insecta: Coleoptera)

    Telnov, Dmitry (Baltijas Koleopterologijas Instituts/Baltic Institute of Coleopterology, 2018-12-23)
    Two new Australian Anthicidae genera, Australosteropes gen. nov. (Steropinae) and Sahulanthicus gen. nov. (Anthicinae: Anthicini) are described, diagnosed, and illustrated. Some critical morphological characters of these new groups and the subfamilies to which they belong are discussed. New combinations are made for the following 18 taxa: Australosteropes davidsonae (Armstrong, 1948) comb. nov. (from Macratria Newman, 1838), Sahulanthicus abundans (Lea, 1922) comb. nov., S. apicalis (King, 1869) comb. nov., S. baudinensis (Champion, 1895) comb. nov., S. brevicollis (King, 1869) comb. nov., S. cavifrons (Champion, 1895) comb. nov., S. crassipes (LaFerté-Sénectère, 1849) comb. nov., S. crassus (King, 1869) comb. nov., S. discoideus (Champion, 1895) comb. nov., S. immaculatus (King, 1869) comb. nov., S. inglorius (Lea, 1896) comb. nov., S. laticollis (MacLeay, 1872) comb. nov., S. luridus (King, 1869) comb. nov., S. monostigma (Champion, 1895) comb. nov., S. obliquefasciatus (King, 1869) comb. nov., S. permutatus (Pic, 1897) comb. nov., S. scutellatus (Lea, 1896) comb. nov. (all from Microhoria Chevrolat, 1877), and S. dilatipennis (Pic, 1900) comb. nov. (from Anthicus Paykull, 1798). Lectotype is designated for Sahulanthicus dilatipennis (Pic, 1900).
  • New, north-easternmost locality for Bembidion monticola Sturm, 1825 (Coleoptera: Carabidae) in Europe: relict of ancient distribution or a result of range expansion?

    Kovalenko, YN; Telnov, Dmitry (Entomological Society of Finland, 2018-09-17)
    A new record of a subpopulation of Bembidion monticola Sturm, 1825 from Arkhangelsk region (Northern Europe, Russia) is discussed. The locality of this record is remote, about 700 km to the east from the northernmost previously known locality of this species. Ecology and distribution of B. monticola in northern Europe are reviewed, as well as possible ways of its spread further to northeast are hypothesised.
  • The air-abrasive technique: A re-evaluation of its use in fossil preparation

    Graham, M; Allington-Jones, L (Society of Vertebrate Paleontology, 2018-08)
    This paper outlines the history of air-abrasion (also known as airbrasion) as a paleontological preparation technique and evaluates various powders and their properties. It explores the rationale behind the selection of abrasive powders and presents, for the first time, trench-scatter experiments through Scanning Electron Microscope (SEM) photography and three-dimensional (3-D) profiling. This article also offers general practical advice and details the results of an international survey of practising fossil preparators.
  • Alkali-rich replacement zones in evolved NYF pegmatites: metasomatic fluids or immiscible melts?

    Muller, A; Spratt, J; Thomas, R; Williamson, BJ; Seltmann, R (International Mineralogical Association, 2018-08-13)
    IMA2018 Abstract submission Pegmatite mineralogy, geochemistry, classification and origins IMA2018-1337 Alkali-rich replacement zones in evolved NYF pegmatites: metasomatic fluids or immiscible melts? Axel Muller* 1, John Spratt2, Rainer Thomas3, Ben J. Williamson4, Reimar Seltmann2 1Natural History Museum, University of Oslo, Oslo, Norway, 2Department of Earth Sciences, Natural History Museum, London, United Kingdom, 3Chemistry and Physics of Earth Materials, German Research Centre for Geoscience GFZ, Potsdam, Germany, 4Camborne School of Mines, University of Exeter, Penryn, United Kingdom What is your preferred presentation method?: Oral or poster presentation : Replacement zones (RZ), which are a common feature of evolved granitic pegmatites, are irregular, commonly alkali-rich zones superimposing, cross-cutting and replacing the primary zonation in almost all consolidated pegmatite bodies. RZ are widely considered to result from late-stage metasomatism even though little is known about the melts and/or fluids involved in their formation. However, the observed textures and mineral paragenesis of RZ cannot be explained by metasomatism in a strict sense. In this study, the nature of the late stage silicate melt forming “cleavelandite” RZ is assessed from textural, mineralogical, chemical and melt inclusion studies of evolved, Proterozoic Niobium-Yttrium-Fluorine (NYF) rare metal pegmatites from Evje–Iveland, southern Norway. These were studied as they are mineralogically simple, compared with RZ in evolved Lithium-Caesium-Tantalum (LCT) pegmatites. Silicate melt inclusions in RZ-forming topaz and “cleavelandite” document high H2O contents of up to18 wt.% of the F-rich silicate melt from which the RZ crystallized. In addition, from mineral compositions (“cleavelandite”, “amazonite”, white mica, garnet, columbite group minerals, topaz, fluorite, and beryl), they must have also been strongly alkaline (Na-dominated) with enrichments in F (at least 4 wt.%), Cs, Rb, Ta, Nb, Mn, Ge, Bi, As, and in some cases also Li compared with host pegmatites. These elements are concentrated in a few RZ-forming minerals resulting in very distinctive mineral-trace element signatures. “Amazonite” is strongly enriched in Cs and Rb and often white mica and beryl in Li and Cs. To acquire these mineral compositions, the overall Li-Cs-Ta-poor Evje-Iveland original pegmatite melt must have undergone extreme internal chemical differentiation resulting in melt/melt immiscibility aiding rheology contrasts and resulting in RZ formation. The resulting RZ-forming H2O-F-rich silicate melt would have shown large differences in viscosity and density, and therefore physical flow/transport properties, to the host pegmatite melt resulting in discordant contacts. The mineralogy and melt inclusion data from the Evje-Iveland pegmatites document a gradient of crystallization temperatures within the investigated pegmatite bodies with highest temperatures at the pegmatite margin (during initial emplacement, ~680°C) and lowest temperatures within the RZ (<500°C). Considering the temperature and pressure conditions of the host rocks gneisses and amphibolites (~650°C, up to 5 kbar) at the time of pegmatite emplacement and the crystallization conditions of the RZ, the Evje- Iveland pegmatites and RZ likely formed over a period of 2.2 million years, assuming an exhumation rate of 1.5 mm per million years and a geothermal gradient of 45°C km-1. Such a long crystallization time contradicts the classical view that pegmatites represent strongly undercooled melts which crystallize relatively fast.
  • A review of the Helophorus frater-praenanus group of species, with description of a new species and additional faunal records of Helophorus Fabricius from China and Bhutan (Coleoptera: Helophoridae)

    ANGUS, RB; Jia, F-L; Chen, Z-N (Austrian Zoological-Botanical Society and the Vienna Coleopterists Society (Wiener Coleopterologenverein, WCV), 2014)
    The six species of the East Palaearctic Helophorus frater-praenanus group (Coleoptera: Helophoridae) are reviewed and a new species, H. aquila sp.n. is described from China (Qinghai). Habitus, head and pronotum and aedeagophores are figured for all the species and a key for their identification is given. Four further species which could be confused with the H. frater-praenanus group are discussed and illustrated. These are H. croaticus KUWERT, 1886, H. pumilio ERICHSON, 1837, H. pitcheri ANGUS, 1970 and H. shatrovskyi ANGUS, 1985. Additional faunal records of Helophorus FABRICIUS species from the Tibetan Plateau and other areas of China are given. Helophorus tuberculatus GYLLENHAL, 1808 is recorded from Bhutan for the first time
  • 'Ava’: a Beaker-associated woman from a cist at Achavanich, Highland, and the story of her (re-) discovery and subsequent study

    Hoole, M; Sheridan, JA; Boyle, A; Booth, T; Brace, S; Diekmann, Y; Olalde, I; Thomas, M; Barnes, I; Evans, J; et al. (Society of Antiquaries of Scotland, 2018-11-21)
    This contribution describes the discovery and subsequent investigation of a cist in a rock-cut pit at Achavanich, Highland. Discovered and excavated in 1987, the cist was found to contain the tightly contracted skeletal remains of a young woman, accompanied by a Beaker, three flint artefacts and a cattle scapula. Initial post excavation work established a date for the skeleton together with details of her age and sex, and preliminary pollen analysis of sediments attaching to the Beaker was undertaken. The findings were never fully published and, upon the death of the excavator, Robert Gourlay, the documentary archive was left in the Highland Council Archaeology Unit. Fresh research in 2014–17, initiated and co-ordinated by the first-named author and funded by the Society of Antiquaries of Scotland with assistance from National Museums Scotland, the Natural History Museum and Harvard Medical School, has produced a significant amount of new information on the individual and on some of the items with which she was buried. This new information includes two further radiocarbon dates, a more detailed osteological report, isotopic information pertaining to the place where she had been raised and to her diet, histological information on the decomposition of her body, and genetic information that sheds light on her ancestry, her hair, eye and skin colour and her intolerance of lactose. (This is the first time that an ancient DNA report has been published in the Proceedings.) Moreover, a facial reconstruction adds virtual flesh to her bones. The significance of this discovery within the Chalcolithic to Early Bronze Age of this part of Scotland is discussed, along with the many and innovative ways in which information on this individual, dubbed ‘Ava’, has been disseminated around the world.
  • Recommended best practices for plastic and litter ingestion studies in marine birds: Collection, processing, and reporting

    Provencher, JF; Borrelle, SB; Bond, AL; Lavers, JL; van Franeker, JA; Kühn, S; Hammer, S; Avery-Gomm, S; Mallory, ML (Canadian Science Publishing, 2019-05-09)
    Marine plastic pollution is an environmental contaminant of significant concern. There is a lack of consistency in sample collection and processing that continues to impede meta-analyses and largescale comparisons across time and space. This is true for most taxa, including seabirds, which are the most studied megafauna group with regards to plastic ingestion research. Consequently, it is difficult to evaluate the impacts and extent of plastic contamination in seabirds fully and accurately, and to make inferences about species for which we have little or no data. We provide a synthesized set of recommendations specific for seabirds and plastic ingestion studies that include best practices in relation to sample collection, processing, and reporting, as well as highlighting some “cross-cutting” methods. We include guidance for how carcasses, regurgitations, and pellets should be handled and treated to prevent cross-contamination, and a discussion of what size class of microplastics can be assessed in each sample type. Although we focus on marine bird samples, we also include standardized techniques to remove sediment and biological material that are generalizable to other taxa. Lastly, metrics and data presentation of ingested plastics are briefly reviewed in the context of seabird studies.
  • Anatomy of Rhinochelys pulchriceps (Protostegidae) and marine adaptation during the early evolution of chelonioids

    Evers, SW; Benson, RBJ; Barrett, PM (PeerJ Inc., 2019-05-01)
    Knowledge of the early evolution of sea turtles (Chelonioidea) has been limited by conflicting phylogenetic hypotheses resulting from sparse taxon sampling and a superficial understanding of the morphology of key taxa. This limits our understanding of evolutionary adaptation to marine life in turtles, and in amniotes more broadly. One problematic group are the protostegids, Early–Late Cretaceous marine turtles that have been hypothesised to be either stem-cryptodires, stem-chelonioids, or crown-chelonioids. Different phylogenetic hypotheses for protostegids suggest different answers to key questions, including (1) the number of transitions to marine life in turtles, (2) the age of the chelonioid crown-group, and (3) patterns of skeletal evolution during marine adaptation. We present a detailed anatomical study of one of the earliest protostegids, Rhinochelys pulchriceps from the early Late Cretaceous of Europe, using high-resolution mCT. We synonymise all previously named European species and document the variation seen among them. A phylogeny of turtles with increased chelonioid taxon sampling and revised postcranial characters is provided, recovering protostegids as stem-chelonioids. Our results imply a mid Early Cretaceous origin of total-group chelonioids and an early Late Cretaceous age for crown-chelonioids, which may inform molecular clock analyses in future. Specialisations of the chelonioid flipper evolved in a stepwise-fashion, with innovations clustered into pulses at the origin of total-group chelonioids, and subsequently among dermochelyids, crown-cheloniids, and gigantic protostegids from the Late Cretaceous.
  • Pushing the limits of whole genome amplification: successful sequencing of RADseq library from a single microhymenopteran (Chalcidoidea, Trichogramma)

    Cruaud, A; Groussier, G; Genson, G; Saune, L; Polaszek, A; Rasplus, J-Y (PeerJ, 2018-10-16)
    A major obstacle to high-throughput genotyping of microhymenoptera is their small size. As species are difficult to discriminate, and because complexes may exist, the sequencing of a pool of specimens is hazardous. Thus, one should be able to sequence pangenomic markers (e.g., RADtags) from a single specimen. To date, whole genome amplification (WGA) prior to library construction is still a necessity as at most 10 ng of DNA can be obtained from single specimens (sometimes less). However, this amount of DNA is not compatible with manufacturer’s requirements for commercial kits. Here we test the accuracy of the GenomiPhi kit V2 on Trichogramma wasps by comparing RAD libraries obtained from the WGA of single specimens (F0 and F1 generation, about1 ng input DNA for the WGA (0.17–2.9 ng)) and a biological amplification of genomic material (the pool of the progeny of the F1 generation). Globally, we found that 99% of the examined loci (up to 48,189 for one of the crosses, 109 bp each) were compatible with the mode of reproduction of the studied model (haplodiploidy) and Mendelian inheritance of alleles. The remaining 1% (0.01% of the analysed nucleotides) could represent WGA bias or other experimental/analytical bias. This study shows that the multiple displacement amplification method on which the GenomiPhi kit relies, could also be of great help for the high-throughput genotyping of microhymenoptera used for biological control, or other organisms from which only a very small amount of DNA can be extracted, such as human disease vectors (e.g., sandflies, fleas, ticks etc.).

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