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  • 251. Chi Fru, Ernest
    et al.
    Ivarsson, Magnus
    Swedish Museum of Natural History, Department of Paleobiology.
    Kilias, Stephanos P
    Bengtson, Stefan
    Swedish Museum of Natural History, Department of Paleobiology.
    Belivanova, Veneta
    Swedish Museum of Natural History, Department of Paleobiology.
    Marone, Federica
    Paul Scherrer Institute.
    Fortin, Danielle
    Broman, Curt
    Stampanoni, Marco
    ETH Zürich.
    Fossilized iron bacteria reveal pathway to biological origin of banded iron formation.2013In: Nature Communications, ISSN 2041-1723, Vol. 4, no 2050, p. 1-7Article in journal (Refereed)
    Abstract [en]

    Debates on the formation of banded iron formations in ancient ferruginous oceans are dominated by a dichotomy between abiotic and biotic iron cycling. This is fuelled by difficulties in unravelling the exact processes involved in their formation. Here we provide fossil environmental evidence for anoxygenic photoferrotrophic deposition of analogue banded iron rocks in shallow marine waters associated with an Early Quaternary hydrothermal vent field on Milos Island, Greece. Trace metal, major and rare earth elemental compositions suggest that the deposited rocks closely resemble banded iron formations of Precambrian origin. Well-preserved microbial fossils in combination with chemical data imply that band formation was linked to periodic massive encrustation of anoxygenic phototrophic biofilms by iron oxyhydroxide alternating with abiotic silica precipitation. The data implicate cyclic anoxygenic photoferrotrophy and their fossilization mechanisms in the construction of microskeletal fabrics that result in the formation of characteristic banded iron formation bands of varying silica and iron oxide ratios.

  • 252. Chi Fru, Ernest
    et al.
    Kilias, Stephanos
    Ivarsson, Magnus
    Swedish Museum of Natural History, Department of Paleobiology.
    Rattray, Jane
    Gkika, Katerina
    McDonald, Iain
    He, Qian
    Broman, Curt
    Sedimentary mechanisms of a modern banded ironformation on Milos Island, GreeceIn: Solid earthArticle in journal (Refereed)
  • 253.
    Chi Fru, Ernest
    et al.
    Department of Geological Sciences, 10691, Stockholm University, Stockholm, Sweden; School of Earth and Ocean Sciences, Cardiff University, Park Place, CF10 3AT Cardiff, UK.
    Kilias, Stephanos
    Department of Economic Geology and Geochemistry, Faculty of Geology and Geoenvironment, National and Kapodistrian University of Athens, Panepistimiopolis, Zographou, 15784, Athens, Greece.
    Ivarsson, Magnus
    Swedish Museum of Natural History, Department of Paleobiology.
    Rattray, Jayne E.
    Department of Geological Sciences, 10691, Stockholm University, Stockholm, Sweden.
    Gkika, Katerina
    Department of Economic Geology and Geochemistry, Faculty of Geology and Geoenvironment, National and Kapodistrian University of Athens, Panepistimiopolis, Zographou, 15784, Athens, Greece.
    McDonald, Iain
    School of Earth and Ocean Sciences, Cardiff University, Park Place, CF10 3AT Cardiff, UK.
    He, Qian
    School of Chemistry, Cardiff University, Park Place, CF10 3AT Cardiff, UK.
    Broman, Curt
    Department of Geological Sciences, 10691, Stockholm University, Stockholm, Sweden.
    Sedimentary mechanisms of a modern banded iron formation on MIlos Island, Greece2018In: Solid Earth, ISSN 1869-9510, E-ISSN 1869-9529, Vol. 9, p. 573-598Article in journal (Refereed)
    Abstract [en]

    An early Quaternary shallow submarine hydrothermal iron formation (IF) in the Cape Vani sedimentary basin (CVSB) on Milos Island, Greece, displays banded rhythmicity similar to Precambrian banded iron formation (BIF). Field-wide stratigraphic and biogeochemical reconstructions show two temporal and spatially isolated iron deposits in the CVSB with distinct sedimentological character. Petrographic screening suggests the presence of a photoferrotrophic-like microfossil-rich IF (MFIF), accumulated on a basement consisting of andesites in a ∼ 150m wide basin in the SW margin of the basin. A banded nonfossiliferous IF (NFIF) sits on top of the Mn-rich sandstones at the transition to the renowned Mn-rich formation, capping the NFIF unit. Geochemical data relate the origin of the NFIF to periodic submarine volcanism and water column oxidation of released Fe(II) in conditions predominated by anoxia, similar to the MFIF. Raman spectroscopy pairs hematite-rich grains in the NFIF with relics of a carbonaceous material carrying an average δ13Corg signature of ∼ −25‰. A similar δ13Corg signature in the MFIF could not be directly coupled to hematite by mineralogy. The NFIF, which postdates large-scale Mn deposition in the CVSB, is composed primarily of amorphous Si (opal-SiO2 ⋅ nH2O) while crystalline quartz (SiO2) predominates the MFIF. An intricate interaction between tectonic processes, changing redox, biological activity, and abiotic Si precipitation are proposed to have collectively formed the unmetamorphosed BIF-type deposits in a shallow submarine volcanic center. Despite the differences in Precambrian ocean–atmosphere chemistry and the present geologic time, these formation mechanisms coincide with those believed to have formed Algoma-type BIFs proximal to active seafloor volcanic centers.

  • 254.
    Chi Fru, Ernest
    et al.
    Stockholm University, Department of Geological Sciences.
    Rodríguez, Nathalie
    Stockholm University Department of Geological Sciences.
    Partin, Camille
    University of Saskatchewan, Canada.
    Lalonde, Stefan
    Université de Bretagne Occidentale, France.
    Andersson, Per
    Swedish Museum of Natural History, Department of Geology.
    Weiss, Dominik
    Imperial College, London, UK.
    El Albani, Abderrazak
    Université de Poitiers, France.
    Rodushkin, Ilia
    ALS Scandinavia, Sweden.
    Konhauser, Kurt
    University of Alberta, Canada.
    Cu isotopes in marine black shales record the Great Oxidation Event2016In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 113, no 18, p. 4941-4946Article in journal (Refereed)
    Abstract [en]

    The oxygenation of the atmosphere ∼2.45–2.32 billion years ago (Ga) is one of the most significant geological events to have affected Earth’s redox history. Our understanding of the timing and processes surrounding this key transition is largely dependent on the development of redox-sensitive proxies, many of which remain unexplored. Here we report a shift from negative to positive copper isotopic compositions (δ65CuERM-AE633) in organic carbon-rich shales spanning the period 2.66–2.08 Ga. We suggest that, before 2.3 Ga, a muted oxidative supply of weathering-derived copper enriched in 65Cu, along with the preferential removal of 65Cu by iron oxides, left seawater and marine biomass depleted in 65Cu but enriched in 63Cu. As banded iron formation deposition waned and continentally sourced Cu became more important, biomass sampled a dissolved Cu reservoir that was progressively less fractionated relative to the continental pool. This evolution toward heavy δ65Cu values coincides with a shift to negative sedimentary δ56Fe values and increased marine sulfate after the Great Oxidation Event (GOE), and is traceable through Phanerozoic shales to modern marine settings, where marine dissolved and sedimentary δ65Cu values are universally positive. Our finding of an important shift in sedimentary Cu isotope compositions across the GOE provides new insights into the Precambrian marine cycling of this critical micronutrient, and demonstrates the proxy potential for sedimentary Cu isotope compositions in the study of biogeochemical cycles and oceanic redox balance in the past.

  • 255. Chiappe, Luis M
    et al.
    Lamb, James P
    Ericson, Per G P
    Swedish Museum of Natural History, Research Division.
    New enantiornithine bird from the marine Upper Cretaceous of Alabama2002In: Journal of Vertebrate Paleontology, ISSN 0272-4634, E-ISSN 1937-2809, Vol. 22, no 1, p. 170-174Article in journal (Refereed)
  • 256. Chiarle, Alberto
    et al.
    Kronestedt, Torbjörn
    Swedish Museum of Natural History, Department of Zoology.
    Isaia, Marco
    Courtship behavior in European species of the genus Pardosa (Araneae, Lycosidae)2013In: Journal of Arachnology, ISSN 0161-8202, Vol. 41, no 2, p. 108-125Article in journal (Refereed)
  • 257.
    Choo, Thereis
    et al.
    School of Integrative Plant Science, Cornell University, Ithaca,.
    Escapa, Ignacio
    CONICET, Museo Paleontológico Egidio Feruglio, Trelew U9100GYO, Chubut, Argentina.
    Benjamin, Bomfleur
    Swedish Museum of Natural History, Department of Paleobiology.
    Monotypic colonies of Clathropteris meniscioides (Dipteridaceae) from the Early Jurassic of central Patagonia, Argentina: implications for taxonomy and palaeoecology2016In: Palaeontographica. Abteilung B, Palaophytologie, ISSN 0375-0299, Vol. 294, p. 85-109Article in journal (Refereed)
    Abstract [en]

    A collection of over 130 specimens of the fossil dipterid fern Clathropteris meniscioides (Brongn. 1825) Brongn. 1828 from in-situ colonies in the Lower Jurassic of Chubut, Argentina, provides evidence for population-level morphological variation within the species and palaeoecology of the site. Characters such as angle of insertion of secondary veins, tertiary vein arrangement and tooth depth were observed to vary between specimens, and the total range of variation captured by this population was found to overlap and intergrade with the descriptions of several previously identified Clathropteris species. This suggests that species delimitations based on minor differences in such characters should be regarded with skepticism, and that the current number of species ascribed to this genus may be artificially inflated. Abundant C. meniscioides fossils at different development stages buried together in a single, thick bed of sheet-flood deposits provide evidence for the species having formed large, pure colonies in open, disturbed floodplain areas. The characteristic and extremely high leaf-vein densities would have allowed for greater carbon assimilation and rapid growth rates. Altogether, this suggests that the species was a fast-growing pioneer species of floodplains, a prominent part of the Early Jurassic vegetation in Gondwana, and a likely food source for large herbivorous dinosaurs common at that time.

  • 258.
    Chris, Mays
    et al.
    Swedish Museum of Natural History, Department of Paleobiology. Monash University.
    Bevitt, Joseph
    Australian Nuclear Science and Technology Organisation, Research Office, Lucas Heights, Australia.
    Stilwell, Jeffrey
    School of Earth, Atmosphere and Environment, Monash University, Clayton, Victoria, Australia.
    Pushing the limits of neutron tomography in palaeontology: Three-dimensional modelling of in situ resin within fossil plants2017In: Palaeontologia Electronica, ISSN 1935-3952, E-ISSN 1094-8074, Vol. 20, no 3, p. 1-12, article id 20.3.57AArticle in journal (Refereed)
    Abstract [en]

    Computed tomography is an increasingly popular technique for the non-destructivestudy of fossils. Whilst the science of X-ray computed tomography (CT) has greatlymatured since its first fossil applications in the early 1980s, the applications and limitationsof neutron tomography (NT) remain relatively unexplored in palaeontology. Thesehighest resolution neutron tomographic scans in palaeontology to date were conductedon a specimen of Austrosequoia novae-zeelandiae (Ettingshausen) Mays and Cantrillrecovered from mid-Cretaceous (Cenomanian; ~100–94 Ma) strata of the ChathamIslands, eastern Zealandia. Previously, the species has been identified with in situ fossilresin (amber); the new neutron tomographic analyses demonstrated an anomalouslyhigh neutron attenuation signal for fossil resin. The resulting data provided astrong contrast between, and distinct three-dimensional representations of the: 1) fossilresin; 2) coalified plant matter; and 3) sedimentary matrix. These data facilitated ananatomical model of endogenous resin bodies within the cone axis and bract-scalecomplexes. The types and distributions of resin bodies support a close alliance withSequoia Endlicher (Cupressaceae), a group of conifers whose extant members areonly found in the Northern Hemisphere. This study demonstrates the feasibility of NTas a means to differentiate chemically distinct organic compounds within fossils.Herein, we make specific recommendations regarding: 1) the suitability of fossil preservationstyles for NT; 2) the conservation of organic specimens with hydrogenous consolidantsand adhesives; and 3) the application of emerging methods (e.g., neutronphase contrast) for further improvements when imaging fine-detailed anatomical structures.These findings demonstrate that we are still far from reaching the conceptuallimits of NT as a means of virtually extracting fossils, or imaging their internal anatomyeven when embedded within a rock matrix.

  • 259. Cibois, Alice
    et al.
    Gelang, Magnus
    Alström, Per
    Pasquet, Eric
    Fjeldså, Jon
    Ericson, Per G P
    Swedish Museum of Natural History, Department of Bioinformatics and Genetics.
    Olsson, Urban
    Comprehensive phylogeny of the laughingthrushes and allies (Aves, Leiothrichidae), and a proposal for a revised taxonomy2018In: Zoologica Scripta, ISSN 0300-3256, E-ISSN 1463-6409, Vol. 47, p. 428-440Article in journal (Refereed)
  • 260.
    Claeson,, Dick
    Sveriges geologiska undersökning.
    Persson, Per-Olof
    Swedish Museum of Natural History, Department of Geology.
    Morris, George
    Sveriges geologiska undersökning.
    U-Pb zircon age of host quartz trachyte at the Kallak iron ore deposit east of Björkholmen, map sheet 27I Tjåmotis SO, Norrbotten County2018Report (Other academic)
  • 261.
    Claeson, Dick
    Sveriges geologiska undersökning.
    Persson, Per-Olof
    Swedish Museum of Natural History, Department of Geology.
    U-Pb zircon age of metagranite with relict phenocryst texture at Linavare, map sheet 27K Nattavaara, Norbotten county2018Report (Other academic)
    Abstract [en]

    Norrbotten, Sweden is a key area of Europe for future exploration and mining. To establish age relations for magmatic activity and metamorphic overprinting in this area, the sampled rock was selected (Fig. 1, 2, 21). This rock occurs at Linavare as mega-xenoliths of strongly deformed, foliated, recrystallised and low-radiation metagranite in massive subvolcanic granite to rhyolite porphyry that was age determined to 1870 ± 6 Ma, giving a lower age of the high-grade metamorphic event (this issue). The age of the regional metamorphic event may be deduced from the age of these two rocks, occurring between their igneous crystallisation ages. Determine the magmatic age of the metagranite is the main aim and if the zircon display metamorphic rims or overgrowths, these should be studied too.

  • 262.
    Claeson,, Dick
    Sveriges geologiska undersökning.
    Persson, Per-Olof
    Swedish Museum of Natural History, Department of Geology.
    Morris, George
    Sveriges geologiska undersökning.
    U-Pb zircon age of the host granite of the REE and Mo (U, Th, Nb, Ta) mineralisation at Tåresåive, map sheet 27J Porjus SV, Norrbotten County2018Report (Other academic)
  • 263.
    Claesson, Stefan
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Bibikova, Elena
    Vernadsky Institute of Geochemistry and Analytical Chemistry RAS, Kosygin St 19, 119991 Moscow, Russia.
    Shumlyanskyy, Leonid
    M. P. Semenenko Institute of Geochemistry, Mineralogy and Ore Formation, Palladina Ave. 34, 03142 Kyiv, Ukraine.
    Dhuime, Bruno
    Department of Earth and Environmental Sciences, University of St Andrews, North Streeet, St Andrews KYI6 9AL, UK.
    Hawkesworth, C. H.
    Department of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS8, 1RJ, UK.
    The oldest crust in the Ukrainian Shield - Eoarchaean U-Pb ages and Hf-Nd constraints from enderbites and metasediments2014In: Continent Formation Through Time / [ed] Roberts, N. M. W., van Kranendonk, M., Parman, S., Shirey, S. and Clift, P. D., London: The Geological Society Publishing House, 2014, Vol. 389Chapter in book (Refereed)
    Abstract [en]

    The oldest crust in the Ukrainian Shield occurs in the Podolian and Azov domains which both include Eoarchaeanarchaean components. U-Pb age data for Dniestr-Bug enderbites, Podolian Domain, indicate these are ca. 3.75 Ga old, and Lu-Hf isotope date indicate extraction from chondritic to mildly isotopically depleted sources with εHf up to ca. +2. Nd model ages support their Eoarchaeanarchaean age, while model ages for Dniestr-Bug metasedimentary gneisses indicate that these also include younger crustal material. Most of the Hf-age data for metasedimentary zircon from the Soroki greenstone belt, Azov Domain, reflects Eoarchaeanarchaean primary crustal sources with chondritic to mildly depleted Hf isotope signatures at 3.75 Ga. A minor portion is derived from Mesoarchaeanarchaean crust with a depleted εHf signature of ca. +4 at 3.1 Ga. U-Pb zircon ages from Fedorivka greenstone belt metasediments are consistent with the Soroki age data, but also include a 2.7‒2.9 Ga component. Nd whole rock model ages provide support for a younger crustal component in the latter. Both domains have been subject to Neoarchaeanarchaean, ca. 2.8 Ga, and Palaeoproterozoic, ca. 2.0 Ga metamorphism. The spatial distribution indicates that the Podolian and Azov domains have evolved independently of each other before the amalgamation of the Ukrainian Shield.

  • 264.
    Claesson, Stefan
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Bibikova, Elena V.
    Vernadsky Institute of Geochemistry and Analytical Chemistry, R.A.S., Moscow, Russia.
    Shumlyanskyy, Leonid
    M.P Semenenko Institute of Geochemistry, Mineralogy and Ore Formation, Palladina Ave. 34, 03680 Kyiv, Ukraine.
    Whitehouse, Martin J.
    Swedish Museum of Natural History, Department of Geology.
    Billström, Kjell
    Swedish Museum of Natural History, Department of Geology.
    Can oxygen isotopes in magmatic zircon be modified by metamorphism? A case study from the Eoarchean Dniester-Bug Series, Ukrainian Shield2016In: Precambrian Research, ISSN 0301-9268, E-ISSN 1872-7433, Vol. 273, p. 1-11Article in journal (Refereed)
  • 265. Clymans, W.
    et al.
    Conley, D. J.
    Battles, J. J.
    Frings, Patrick J
    Swedish Museum of Natural History, Department of Geology.
    Koppers, M. M.
    Likens, G. E.
    Johnson, C. E.
    Silica uptake and release in live and decaying biomass in a northern hardwood forest2016In: Ecology, ISSN 0012-9658, E-ISSN 1939-9170, Vol. 97, no 11, p. 3044-3057Article in journal (Refereed)
    Abstract [en]

    In terrestrial ecosystems, a large portion (20-80%) of the dissolved Si (DSi) in soil solution has passed through vegetation. While the importance of this terrestrial Si filter is generally accepted, few data exist on the pools and fluxes of Si in forest vegetation and the rate of release of Si from decomposing plant tissues. We quantified the pools and fluxes of Si through vegetation and coarse woody debris (CWD) in a northern hardwood forest ecosystem (Watershed 6, W6) at the Hubbard Brook Experimental Forest (HBEF) in New Hampshire, USA. Previous work suggested that the decomposition of CWD may have significantly contributed to an excess of DSi reported in stream-waters following experimental deforestation of Watershed 2 (W2) at the HBEF. We found that woody biomass (wood+bark) and foliage account for approximately 65% and 31%, respectively, of the total Si in biomass at the HBEF. During the decay of American beech (Fagus grandifolia) boles, Si loss tracked the whole-bole mass loss, while yellow birch (Betula alleghaniensis) and sugar maple (Acer saccharum) decomposition resulted in a preferential Si retention of up to 30% after 16yr. A power-law model for the changes in wood and bark Si concentrations during decomposition, in combination with an exponential model for whole-bole mass loss, successfully reproduced Si dynamics in decaying boles. Our data suggest that a minimum of 50% of the DSi annually produced in the soil of a biogeochemical reference watershed (W6) derives from biogenic Si (BSi) dissolution. The major source is fresh litter, whereas only similar to 2% comes from the decay of CWD. Decay of tree boles could only account for 9% of the excess DSi release observed following the experimental deforestation of W2. Therefore, elevated DSi concentrations after forest disturbance are largely derived from other sources (e.g., dissolution of BSi from forest floor soils and/or mineral weathering).

  • 266. Cole, Theresa
    et al.
    Rawlence, Nic
    Dussex, Nicolas
    Swedish Museum of Natural History, Department of Bioinformatics and Genetics.
    Elleberg, Ursulla
    Houston, Dave
    Mattern, Thomas
    Miskelly, Colin
    Morrisson, Kyle
    Scofield, Paul
    Tennyson, Alan
    Tompson, David
    Wood, Jamie
    Waters, Jonathan
    Ancient DNA of crested penguins: Testing for temporal genetic shifts in the world's most diverse penguin clade2018In: Molecular Phylogenetics and Evolution, ISSN 1055-7903, E-ISSN 1095-9513, Vol. 131, p. 72-79Article in journal (Refereed)
    Abstract [en]

    Human impacts have substantially reduced avian biodiversity in many parts of the world, particularly on isolated islands of the Pacific Ocean. The New Zealand archipelago, including its five subantarctic island groups, holds breeding grounds for a third of the world's penguin species, including several representatives of the diverse crested penguin genus Eudyptes. While this species-rich genus has been little studied genetically, recent population estimates indicate that several Eudyptes taxa are experiencing demographic declines. Although crested penguins are currently limited to southern regions of the New Zealand archipelago, prehistoric fossil and archaeological deposits suggest a wider distribution during prehistoric times, with breeding ranges perhaps extending to the North Island. Here, we analyse ancient, historic and modern DNA sequences to explore two hypotheses regarding the recent history of Eudyptes in New Zealand, testing for (1) human-driven extinction of Eudyptes lineages; and (2) reduced genetic diversity in surviving lineages. From 83 prehistoric bone samples, each tentatively identified as ‘Eudyptes spp.’, we genetically identified six prehistoric penguin taxa from mainland New Zealand, including one previously undescribed genetic lineage. Moreover, our Bayesian coalescent analyses indicated that, while the range of Fiordland crested penguin (E. pachyrhynchus) may have contracted markedly over the last millennium, genetic DNA diversity within this lineage has remained relatively constant. This result contrasts with human-driven biodiversity reductions previously detected in several New Zealand coastal vertebrate taxa.

  • 267. Collinson, J M
    et al.
    McGowan, R Y
    Irestedt, Martin
    Swedish Museum of Natural History, Department of Bioinformatics and Genetics.
    First British records of ‘Eastern’ and ‘Western’ Subalpine Warblers2014In: British birds, Vol. 107, p. 282-285Article, book review (Other (popular science, discussion, etc.))
  • 268. Conand, Chantal
    et al.
    Mulochau, Thierry
    Stöhr, Sabine
    Swedish Museum of Natural History, Department of Zoology.
    Eléaume, Marc
    Chabanet, Pascale
    Inventory of echinoderms in the Iles Eparses (Europa, Glorieuses, Juan de Nova), Mozambique Channel, France2016In: Acta Oecologica, ISSN 1146-609X, E-ISSN 1873-6238, Vol. 72, p. 53-61-Article in journal (Refereed)
  • 269. Conley, Daniel
    et al.
    Frings, Patrick J
    Swedish Museum of Natural History, Department of Geology.
    Fontorbe, Guillaume
    Clymans, Wim
    Stadmark, Johanna
    Hendry, Katherine
    Marron, Alan
    De La Rocha, Christina
    Biosilicification drives a decline of dissolved Si in the oceans through geologic time2017In: Frontiers in Marine Science, E-ISSN 2296-7745Article in journal (Refereed)
    Abstract [en]

    Biosilicification has driven variation in the global Si cycle over geologic time. The evolution of different eukaryotic lineages that convert dissolved Si (DSi) into mineralized structures (higher plants, siliceous sponges, radiolarians and diatoms) has driven a secular decrease in DSi in the global ocean leading to the low DSi concentrations seen today. Recent studies, however, have questioned the timing previously proposed for the DSi decreases and the concentration changes through deep time, which would have major implications for the cycling of carbon and other key nutrients in the ocean. Here, we combine relevant genomic data with geological data and present new hypotheses regarding the impact of the evolution of biosilicifying organisms on the DSi inventory of the oceans throughout deep time. Although there is no fossil evidence for true silica biomineralization until the late Precambrian, the timing of the evolution of silica transporter genes suggests that bacterial silicon-related metabolism has been present in the oceans since the Archean with eukaryotic silicon metabolism already occurring in the Neoproterozoic. We hypothesize that biological processes have influenced oceanic DSi concentrations since the beginning of oxygenic photosynthesis.

  • 270.
    Conrad, Sarah
    et al.
    Luleå University of Technology.
    Ingri, Johan
    Luleå University of Technology.
    Gelting, Johan
    Leleå University of Technology.
    Nordblad, Fredrik
    Luleå University of Technology.
    Engström, Emma
    Luleå University of Technology.
    Rodushkin, Ilia
    ALS Laboratory Group, Luleå.
    Andersson, Per
    Swedish Museum of Natural History, Research Division.
    Porcelli, Don
    Oxford University, Oxford.
    Gustafsson, Örjan
    Stockholm University, Stockholm.
    Semiletov, Igor
    University of Alaska, USA.
    Öhlander, Björn
    Luleå University of Technology.
    Distributionof Fe isotopes in particles and colloids in the salinity gradient along theLena River plume, Laptev Sea2019In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 16, p. 1305-1319Article in journal (Refereed)
    Abstract [en]

    Riverine Fe input is the primary Fe source to the ocean. This study is focused on the distribution of Fe along the Lena River freshwater plume in the Laptev Sea using samples from a 600 km long transect in front of the Lena River mouth. Separation of the particulate (>0.22µm), colloidal (0.22µm – 1kDa), and truly dissolved (<1kDa) fractions of Fe was carried out. The total Fe concentrations ranged from 0.15 to 57 µM with Fe dominantly as particulate Fe. The loss of > 99% of particulate Fe and about 90% of the colloidal Fe was observed across the shelf, while the truly dissolved phase was almost constant across the Laptev Sea. Thus, the truly dissolved Fe could be an important source of bioavailable Fe for plankton in the central Arctic Ocean, together with the colloidal Fe. Fe-isotope analysis showed that the particulate phase and the sediment below the Lena River freshwater plume had negative δ56Fe values (relative to IRMM-14). The colloidal Fe phase showed negative δ56Fe values close to the river mouth (about -0.20‰) and positive δ56Fe values in the outermost stations (about +0.10‰).

    We suggest that the shelf zone acts as a sink for Fe particles and colloids with negative δ56Fe values, representing chemically reactive ferrihydrites. While the positive δ56Fe values of the colloidal phase within the outer Lena River freshwater plume, might represent Fe-oxyhydroxides, which remain in the water column, and will be the predominant δ56Fe composition in the Arctic Ocean.

  • 271.
    Cooper, Mark
    et al.
    University of Manitoba, Winnipeg, Canada.
    Hawthorne, Frank
    University of Manitoba, Winnipeg, Canada.
    Langhof, Jörgen
    Swedish Museum of Natural History, Department of Geology.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Holtstam, Dan
    Swedish Museum of Natural History, Department of Geology.
    Wiklundite, ideally Pb2[4](Mn2+,Zn)3(Fe3+,Mn2+)2(Mn2+,Mg)19(As3+O3)2[(Si,As5+)O4]6 (OH)18Cl6, a new mineral from Långban, Filipstad, Värmland, Sweden: Description and crystal structure2017In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 81, no 4, p. 841-855Article in journal (Refereed)
  • 272.
    Cornacchia, Irene
    et al.
    Dipartimento di Scienze della Terra, Sapienza Universita di Roma.
    Andersson, Per
    Swedish Museum of Natural History, Department of Geology.
    Agostine, Samuele
    Instituto di Geosciencze e Georisorse, CNR, Pisa.
    Brandanao, Marco
    Dipartimento di Scienze della Terra, Sapienza Universita di Roma.
    Strontium stratigraphy of the upper Miocene Lithothamnion Limestone in the Majella Mountain, central Italy, and its palaeoenvironmental implications2017In: Lethaia: an international journal of palaeontology and stratigraphy, ISSN 0024-1164, E-ISSN 1502-3931, Vol. 50, no 4, p. 561-575Article in journal (Refereed)
    Abstract [en]

    The87Sr/86Sr isotope ratio has been widely used as aphysical tool to date and correlate carbonate successions due to the long Srresidence time in comparison with the ocean mixing time. If this method workson oceanic successions, marginal basins may show different Sr isotope recordsin comparison with the coeval ocean one due to sea-level variations,continental run-off and restricted water exchanges. In this work, we present the87Sr/86Sr isotope record of the upper Miocene carbonateramp of the Lithothamnion Limestone(Majella Mountain, central Apennines), as an example of the onset of restrictedwater exchanges between a marginal basin and the ocean water masses. The overalllatemost Tortonian–earlyMessinian Sr isotope record of the Lithothamnion Limestonefits below the global reference line. This deviation has been interpreted as dueto the strong control that freshwater input and enhanced continental run-off,linked to the migration of the Apennine accretionary wedge and foredeep system,have had on the central Adriatic water chemistry. These results imply that anaccurate oceanographic and geodynamic framework along with diagenetic overprintinvestigation has to be taken into consideration prior to apply SIS oncarbonate successions on marginal basins, even when facies analyses indicatefully marine conditions. This seems to be the case for the upper MioceneCentral Mediterranean carbonate successions, but may have more general validityand be extended to other recent or past marginal basins.

  • 273. Costa Baião, Guilherme
    Revision of the West Palaearctic species of Rhoptromeris Förster, 1869 (Hymenoptera: Figitidae: Eucoilinae)2018In: Journal of Natural History, ISSN 0022-2933, E-ISSN 1464-5262, Vol. 52, p. 1201-1224Article in journal (Refereed)
    Abstract [en]

    The West Palearctic species of Rhoptromeris are revised. A total of 11 species are recognised as valid in this region, including four newly described species: Rhoptromeris dichromata sp. nov., Rhoptromeris koponeni sp. nov., Rhoptromeris leptocornis sp. nov. and Rhoptromeris macaronesiensis sp. nov. Eucoila luteicornis Ionescu, 1959 is synonymised with Rhoptromeris heptoma (Hartig, 1840) syn. nov. A checklist of the Holarctic Rhoptromeris is presented and an identification key to the West Palearctic species is provided.

  • 274. Cote, Susanne M.
    et al.
    Werdelin, Lars
    Swedish Museum of Natural History, Department of Paleobiology.
    Seiffert, E. R.
    Barry, J. C.
    The enigmatic Early Miocene mammal Kelba and its relationship to the order Ptolemaiida2007In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 104, p. 5510-5515Article in journal (Refereed)
    Abstract [en]

    Kelba quadeemae, a fossil mammal from the Early Miocene of East Africa, was originally named on the basis of three isolated upper molars. Kelba has previously been interpreted as a creodont, a pantolestid, an insectivoran, and a hemigaline viverrid. The true affinities of this taxon have remained unclear because of the limited material and its unique morphology relative to other Miocene African mammals. New material of Kelba from several East African Miocene localities, most notably a skull from the Early Miocene locality of Songhor in Western Kenya, permits analysis of the affinities of Kelba and documents the lower dentition of this taxon. Morphological comparison of this new material clearly demonstrates that Kelba is a member of the order Ptolemaiida, a poorly understood group whose fossil record was previously restricted to the Oligocene Fayum deposits of northern Egypt. Phylogenetic analysis supports the monophyly of the Ptolemaiida, including Kelba, and recovers two monophyletic clades within the order. We provide new family names for these groups and an emended diagnosis for the order. The discovery of ptolemaiidans from the Miocene of East Africa is significant because it extends the known temporal range of the order by >10 million years and the geographic range by >3,200 km. Although the higher-level affinities of the Ptolemaiida remain obscure, their unique morphology and distribution through a larger area of Africa (and exclusively Africa) lend support to the idea that Ptolemaiida may have an ancient African origin.

  • 275. Cotton, James A.
    et al.
    Berriman, Matthew
    Dalén, Love
    Swedish Museum of Natural History, Department of Bioinformatics and Genetics.
    Barnes, Ian
    Eradication genomics-lessons for parasite control2018In: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 361, no 6398, p. 130-131Article in journal (Refereed)
  • 276. Coulianos, C. C.
    et al.
    Karlsson, Thomas
    Swedish Museum of Natural History, Department of Botany.
    Några för Sverige nya gallbildningar samt nya landskapsfynd [Some plant galls new to Sweden and new provincial records]2014In: Svensk Botanisk Tidskrift, ISSN 0039-646X, Vol. 108, p. 297-301Article in journal (Other (popular science, discussion, etc.))
  • 277. Coulson, S.J.
    et al.
    Convey, P.
    Aakra, K.
    Aarvik, L.
    Ávila-Jiménez, M.L.
    Babenko, A.
    Biersma, E.M.
    Boström, Sven
    Swedish Museum of Natural History, Department of Zoology.
    Brittain, J.E.
    Carlsson, A.M.
    Christoffersen, K.
    De Smet, W.H.
    Ekrem, T.
    Fjellberg, A.
    Füreder, L.
    Gustafsson, D.
    Gwiazdowicz, D.J.
    Hansen, L.O.
    Holmstrup, M.
    Hullé, M.
    Kaczmarek, L.
    Kolicka, M.
    Kuklin, V.
    Lakka, H.-K.
    Lebedeva, N.
    Makarova, O.
    Maraldo, K.
    Melekhina, E.
    Ödegaard, F.
    Pilskog, H.E.
    Simon, J.C.
    Sohlenius, Björn
    Swedish Museum of Natural History, Department of Zoology.
    Solhöy, T.
    Söli, G.
    Stur, E.
    Tanasevitch, A.
    Taskareva, A.
    Velle, G.
    Zawierucha, K.
    Zmudczynska-Skarbek, K.
    The terrestrial and freshwater invertebrate biodiversity of the archipelagoes of the Barents Sea; Svalbard, Franz Josef Land and Novaya Zemlya2014In: Soil Biology and Biochemistry, ISSN 0038-0717, E-ISSN 1879-3428, Vol. 68, p. 440-470Article in journal (Refereed)
  • 278. Crossley, R J
    et al.
    Evans, K A
    Jeon, Heejin
    Kilburn, M R
    Insights into sulfur cycling at subduction zones from in-situ isotopic analysis of sulfides in high-pressure serpentinites and ‘hybrid’ samples from Alpine Corsica2018In: Chemical GeologyArticle in journal (Refereed)
  • 279. Crous, P.W.
    et al.
    Quaedvlieg, W
    Hansen, Karen
    Swedish Museum of Natural History, Department of Botany.
    Hawksworth, D.L.
    Groenwald, J.Z.
    Phacidium and Ceuthospora (Phacidiaceae) are congeneric: taxonomic and nomenclatural implications2014In: IMA Fungus, ISSN 2210-6340, E-ISSN 2210-6359, Vol. 5, no 2, p. 173-193Article in journal (Refereed)
  • 280. Crémière, A.
    et al.
    Lepland, A.
    Chand, S.
    Sahy, D.
    Kirsimäe, K.
    Bau, M.
    Whitehouse, Martin J.
    Swedish Museum of Natural History, Department of Geology.
    Noble, S.R.
    Martma, T.
    Thorsnes, T.
    Brunstad, H.
    Fluid source and methane-related diagenetic processes recorded in cold seep carbonates from the Alvheim channel, central North Sea2016In: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 432, p. 16-33Article in journal (Refereed)
    Abstract [en]

    Integrated petrography, mineralogy, geochronology and geochemistry of cold seep carbonate crusts and free gas from the Alvheim channel elucidate diagenetic carbonate precipitation and related seepage histories in the central North Sea. Free gas isotope characteristics coupled with carbonate δ13C values as low as − 66‰ VPDB, indicate a predominantly microbial methane source with minor thermogenic contribution. We estimate that ~ 70% of the carbon sequestered into carbonate precipitates was derived from local oxidation of methane. The early stage of crust growth is represented by microcrystalline aragonite and Mg-calcite (10 to 40% mol MgCO3) cementing seafloor sediments consisting of clays, quartz, feldspar, and minor detrital low Mg-calcite and dolomite. Typical association of aragonite cement with coarse-grained detritus may reflect elevated fluid flow and flushing of fine particles prior to cementation close to the seafloor. Middle rare earth element enrichment in early generation microcrystalline cements containing framboidal pyrite indicates diagenetic precipitation within the zone of anaerobic methane oxidation contiguous to iron reduction. The later generation diagenetic phase corresponds to less abundant radial fibrous and botryoidal aragonite which lines cavities developed within the crusts. In contrast to early generation cements, late generation cavity infills have rare earth elements and Y patterns with small negative Ce anomalies similar to seawater, consistent with carbonate precipitation in a more open, seawater dominated system. Aragonite U–Th ages indicate carbonate precipitation between 6.09 and 3.46 kyr BP in the northern part of the channel, whereas in the southern part precipitation occurred between 1.94 and 0.81 kyr BP reflecting regional changes in fluid conduit position.

  • 281.
    Cui, Ying
    et al.
    Department of Geosciences, The Pennsylvania State University, University Park, PA, United States.
    Bercovici, Antoine
    Department of Geology, Lund University, Lund, Sweden.
    Yu, Jianxin
    State Key Laboratory of Biogeology and Environmental Geology of Ministry of Education, China University of Geosciences (Wuhan), People's Republic of China.
    Kump, Lee R.
    Department of Geosciences, The Pennsylvania State University, University Park, PA, United States.
    Freeman, Katherine
    Department of Geosciences, The Pennsylvania State University, University Park, PA, United States.
    Su, Shangguo
    School of Earth Sciences and Resources, China University of Geosciences (Beijing), People's Republic of China.
    Vajda, Vivi
    Swedish Museum of Natural History, Department of Paleobiology. Department of Geology, Lund University, Sweden.
    Carbon cycle perturbation expressed in terrestrial Permian–Triassic boundary sections in South China2017In: Global and Planetary Change, ISSN 0921-8181, E-ISSN 1872-6364, Vol. 148, p. 272-285Article in journal (Refereed)
    Abstract [en]

    Stable isotopes of inorganic and organic carbon are commonly used in chemostratigraphy to correlatemarine andterrestrial sedimentary sequences based on the assumption that the carbon isotopic signature of the exogenic carbon pool dominates other sources of variability. Here, sediment samples fromfour Permian–Triassic boundary (PTB) sections ofwesternGuizhou and eastern Yunnan provinces in South China, representing a terrestrial tomarine transitional setting,were analyzed for δ13C of organic matter (δ13Corg). These valueswere subsequently compared to published δ13C values of carbonates (δ13Ccarb) from the Global Stratotype Section and Point at Meishan and many other marine and terrestrial sections. A similar isotopic trend evident through all four sections is characterized by a negative shift of 2–3‰ at the top of the Xuanwei Formation, where we tentatively place the PTB. This negative shift also corresponds to a turnover in the vegetation and the occurrence of fungal spores, which is generally interpreted as a proliferation of decomposers and collapse of complex ecosystems during the end-Permian mass extinction event. Moreover, the absolute values of δ13Corg are more extreme in the more distal (marine) deposits. The δ13Corg values for the studied sediments aremore variable compared to coeval δ13Ccarb records from marine records especially in the interval below the extinction horizon. We contend that the depositional environment influenced the δ13Corg values, but that the persisting geographic δ13Corg pattern through the extinction event across the four independent sections is an indication that the atmospheric δ13C signal left an indelible imprint on the geologic record related to the profound ecosystem change during the end-Permian extinction event.

  • 282. Cui, Ying
    et al.
    Bercovici, Antoine
    Yu, Yianxin
    Kump, Lee
    Freeman, Katherine
    Su, Shangguo
    Vajda, Vivi
    Swedish Museum of Natural History, Department of Paleobiology.
    Carbon cycle perturbation expressed in terrestrial Permian–Triassic boundary sections in South China2015In: Global and Planetary Change, ISSN 0921-8181, E-ISSN 1872-6364Article in journal (Refereed)
    Abstract [en]

    Stable isotopes of inorganic and organic carbon are commonly used in chemostratigraphy to correlate marine and terrestrial sedimentary sequences based on the assumption that the carbon isotopic signature of the exogenic carbon pool dominates other sources of variability. Here, sediment samples from four Permian–Triassic boundary (PTB) sections of western Guizhou and eastern Yunnan provinces in South China, representing a terrestrial to marine transitional setting, were analyzed for δ13C of organic matter (δ13Corg). These values were subsequently compared to published δ13C values of carbonates (δ13Ccarb) from the Global Stratotype Section and Point at Meishan and many other marine and terrestrial sections. A similar isotopic trend evident through all four sections is characterized by a negative shift of 2–3‰ at the top of the Xuanwei Formation, where we tentatively place the PTB. This negative shift also corresponds to a turnover in the vegetation and the occurrence of fungal spores, which is generally interpreted as a proliferation of decomposers and collapse of complex ecosystems during the end-Permian mass extinction event. Moreover, the absolute values of δ13Corg are more extreme in the more distal (marine) deposits. The δ13Corg values for the studied sediments are more variable compared to coeval δ13Ccarb records from marine records especially in the interval below the extinction horizon. We contend that the depositional environment influenced the δ13Corg values, but that the persisting geographic δ13Corg pattern through the extinction event across the four independent sections is an indication that the atmospheric δ13C signal left an indelible imprint on the geologic record related to the profound ecosystem change during the end-Permian extinction event.

  • 283. Cunningham, J. A.
    et al.
    Thomas, C.-W.
    Bengtson, Stefan
    Swedish Museum of Natural History, Department of Paleobiology.
    Marone, Federica
    Paul Scherrer Institute.
    Stampanoni, Marco
    ETH Zürich.
    Turner, F. R.
    Bailey, J. V.
    Raff, R. A.
    Raff, E. C.
    Donoghue, Philip C.J.
    University of Bristol.
    Experimental taphonomy of giant sulphur bacteria: implications for the interpretation of the embryo-like Ediacaran Doushantuo fossils.2012In: Proceedings of the Royal Society of London. B. Biological Sciences, ISSN 0962-8452, Vol. 279, no 1734, p. 1857-1864Article in journal (Refereed)
    Abstract [en]

    The Ediacaran Doushantuo biota has yielded fossils interpreted as eukaryotic organisms, either animal embryos or eukaryotes basal or distantly related to Metazoa. However, the fossils have been interpreted alternatively as giant sulphur bacteria similar to the extant Thiomargarita. To test this hypothesis, living and decayed Thiomargarita were compared with Doushantuo fossils and experimental taphonomic pathways were compared with modern embryos. In the fossils, as in eukaryotic cells, subcellular structures are distributed throughout cell volume; in Thiomargarita, a central vacuole encompasses approximately 98 per cent cell volume. Key features of the fossils, including putative lipid vesicles and nuclei, complex envelope ornament, and ornate outer vesicles are incompatible with living and decay morphologies observed in Thiomargarita. Microbial taphonomy of Thiomargarita also differed from that of embryos. Embryo tissues can be consumed and replaced by bacteria, forming a replica composed of a threedimensional biofilm, a stable fabric for potential fossilization. Vacuolated Thiomargarita cells collapse easily and do not provide an internal substrate for bacteria. The findings do not support the hypothesis that giant sulphur bacteria are an appropriate interpretative model for the embryo-like Doushantuo fossils. However, sulphur bacteria may have mediated fossil mineralization and may provide a potential bacterial analogue for other macroscopic Precambrian remains.

  • 284. Cunningham, J.A.
    et al.
    Thomas, C.-W.
    Bengtson, Stefan
    Swedish Museum of Natural History, Department of Paleobiology.
    Kearns, S.L.
    Xiao, S.
    Marone, Federica
    Paul Scherrer Institute.
    Stampanoni, Marco
    ETH Zürich.
    Donoghue, Philip C.J.
    University of Bristol.
    Distinguishing geology from biology in the Ediacaran Doushantuo biota relaxes constraints on the timing of the origin of bilaterians.2012In: Proceedings of the Royal Society. B. Biological Sciences, ISSN 0962-8452, Vol. 279, no 1737, p. 2369-2376Article in journal (Refereed)
    Abstract [en]

    The Ediacaran Doushantuo biota has yielded fossils that include the oldest widely accepted record of the animal evolutionary lineage, as well as specimens with alleged bilaterian affinity. However, these systematic interpretations are contingent on the presence of key biological structures that have been reinterpreted by some workers as artefacts of diagenetic mineralization. On the basis of chemistry and crystallographic fabric, we characterize and discriminate phases of mineralization that reflect: (i) replication of original biological structure, and (ii) void-filling diagenetic mineralization. The results indicate that all fossils from the Doushantuo assemblage preserve a complex me´lange of mineral phases, even where subcellular anatomy appears to be preserved. The findings allow these phases to be distinguished in more controversial fossils, facilitating a critical re-evaluation of the Doushantuo fossil assemblage and its implications as an archive of Ediacaran animal diversity. We find that putative subcellular structures exhibit fabrics consistent with preservation of original morphology. Cells in later developmental stages are not in original configuration and are therefore uninformative concerning gastrulation. Key structures used to identify Doushantuo bilaterians can be dismissed as late diagenetic artefacts. Therefore, when diagenetic mineralization is considered, there is no convincing evidence for bilaterians in the Doushantuo assemblage.

  • 285.
    Cunningham, John A.
    et al.
    Swedish Museum of Natural History, Department of Paleobiology. University of Bristol.
    Liu, Alexander G.
    University of Cambridge.
    Bengtson, Stefan
    Swedish Museum of Natural History, Department of Paleobiology.
    Donoghue, Philip C.J.
    University of Bristol.
    The origin of animals: Can molecular clocks and the fossil record be reconciled?2016In: Bioessays, ISSN 0265-9247, E-ISSN 1521-1878, Vol. 38, p. 1-12Article in journal (Refereed)
    Abstract [en]

    The evolutionary emergence of animals is one of the most significant episodes in the history of life, but its timing remains poorly constrained. Molecular clocks estimate that animals originated and began diversifying over 100 million years before the first definitive metazoan fossil evidence in the Cambrian. However, closer inspection reveals that clock estimates and the fossil record are less divergent than is often claimed. Modern clock analyses do not predict the presence of the crown-representatives of most animal phyla in the Neoproterozoic. Furthermore, despite challenges provided by incomplete preservation, a paucity of phylogenetically informative characters, and uncertain expectations of the anatomy of early animals, a number of Neoproterozoic fossils can reasonably be interpreted as metazoans. A considerable discrepancy remains, but much of this can be explained by the limited preservation potential of early metazoans and the difficulties associated with their identificationin the fossil record. Critical assessment of both recordsmay permitbetter resolutionof the tempo and mode of early animal evolution.

  • 286.
    Cunningham, John A.
    et al.
    Swedish Museum of Natural History, Department of Paleobiology. University of Bristol.
    Vargas, Kelly
    School of Earth Sciences, University of Bristol, Bristol.
    Yin, Zongjun
    State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing.
    Bengtson, Stefan
    Swedish Museum of Natural History, Department of Paleobiology.
    Donoghue, Philip C.J.
    University of Bristol.
    The Weng’an Biota (Doushantuo Formation): an Ediacaran window on soft bodied and multicellular microorganisms.2017In: journal of the geological society, ISSN 2041-479X, Vol. 174, no 5, p. 793-802Article in journal (Refereed)
    Abstract [en]

    The Weng’an Biota is a fossil Konservat-Lagerstätte in South China that is approximately 570-600 million years old and provides an unparalleled snapshot of marine life during the interval in which molecular clocks estimate that animal clades were diversifying. It yields specimens that are three-dimensionally preserved in calcium phosphate with cellular and sometimes subcellular fidelity. The biota includes candidates for the oldest animals in the fossil record, including embryonic, larval and adult forms. We argue that, while the Weng’an Biota includes forms that could be animals, none can currently be assigned to this group with confidence. Nonetheless, the biota offers a rare and valuable window on the evolution of multicellular and soft-bodied organisms in the prelude to the Cambrian radiation.

  • 287.
    Cunningham, John
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Donoghue, Philip C.J.
    University of Bristol.
    Bengtson, Stefan
    Swedish Museum of Natural History, Department of Paleobiology.
    Distinguishing biology from geology in soft-tissue preservation.2014In: Reading and Writing of the Fossil Record: Preservational Pathways to Exceptional Fossilization / [ed] Marc Laflamme, James D. Schiffbauer, Simon A. F. Darroch, The Paleontological Society , 2014, p. 275-287Chapter in book (Refereed)
    Abstract [en]

    Knowledge of evolutionary history is based extensively on relatively rare fossils that preserve soft tissues. These fossils record a much greater proportion of anatomy than would be known solely from mineralized remains and provide key data for testing evolutionary hypotheses in deep time. Ironically, however, exceptionally preserved fossils are often among the most contentious because they are difficult to interpret. This is because their morphology has invariably been affected by the processes of decay and diagenesis, meaning that it is often difficult to distinguish preserved biology from artifacts introduced by these processes. Here we describe how a range of analytical techniques can be used to tease apart mineralization that preserves biological structures from unrelated geological mineralization phases. This approach involves using a series of X-ray, ion, electron and laser beam techniques to characterize the texture and chemistry of the different phases so that they can be differentiated in material that is difficult to interpret. This approach is demonstrated using a case study of its application to the study of fossils from the Ediacaran Doushantuo Biota.

  • 288.
    Cunningham, John
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Vargas, Kelly
    Liu, Pengju
    Belivanova, Veneta
    Swedish Museum of Natural History, Department of Paleobiology.
    Marone, Federica
    Martínez-Pérez, Carlos
    Guizar-Sicairos, Manuel
    Holler, Mirko
    Bengtson, Stefan
    Swedish Museum of Natural History, Department of Paleobiology.
    Donoghue, Philip C.J.
    Critical appraisal of tubular putative eumetazoans from the Ediacaran Weng’an Doushantuo biota2015In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 282, p. 1-9, article id 2151169Article in journal (Refereed)
    Abstract [en]

    Molecular clock analyses estimate that crown-group animals began diversifying hundreds of millions of years before the start of the Cambrian period. However, the fossil record has not yielded unequivocal evidence for animals during this interval. Some of the most promising candidates for Precambrian animals occur in theWeng’an biota of South China, including a suite of tubular fossils assigned to Sinocyclocyclicus, Ramitubus, Crassitubus and Quadratitubus, that have been interpreted as soft-bodied eumetazoans comparable to tabulate corals. Here, we present new insights into the anatomy, original composition and phylogenetic affinities of these taxa based on data from synchrotron radiation X-ray tomographic microscopy, ptychographic nanotomography, scanning electron microscopy and electron probe microanalysis. The patterns of deformation observed suggest that the cross walls of Sinocyclocyclicus and Quadratitubus were more rigid than those of Ramitubus and Crassitubus. Ramitubus and Crassitubus specimens preserve enigmatic cellular clusters at terminal positions in the tubes. Specimens of Sinocyclocyclicus and Ramitubus have biological features that might be cellular tissue or subcellular structures filling the spaces between the crosswalls. These observations are incompatible with a cnidarian interpretation, in which the spaces between cross walls are abandoned parts of the former living positions of the polyp. The affinity of the Weng’an tubular fossils may lie within the algae.

  • 289.
    Cuss, Chad
    et al.
    Trent University Canada.
    Guéguen, Celine
    Trent University Canada.
    Andersson, Per
    Swedish Museum of Natural History, Department of Geology.
    Porcelli, Don
    University of Oxford UK.
    Maximov, Trofim
    North-Eastern Federal University Yakutsk, Russia.
    Kutscher, Liselott
    Swedish Museum of Natural History, Department of Geology.
    Advanced residuals analysis for determining the number of PARAFAC components in dissolved organic matter2016In: Applied Spectroscopy, ISSN 0003-7028, E-ISSN 1943-3530, Vol. 70, no 2, p. 334-346Article in journal (Refereed)
  • 290. Dahlberg, Anders
    et al.
    Edman, Mattias
    Hansen, Karen
    Swedish Museum of Natural History, Department of Botany.
    Jeppson, Mikael
    Karström, Mats
    Knutsson, Tommy
    Krikorev, Michael
    Lindström, Håkan
    Nitare, Johan
    Norden, Björn
    Svensson, Sigvard
    Tedebrand, Jan-Oluf
    786 svampar på 2015 års rödlista2015In: Svensk Mykologisk Tidskrift, ISSN 1653-0357, Vol. 36, p. 91-97-Article in journal (Other (popular science, discussion, etc.))
    Abstract [en]

    A new Swedish Red List was published April 28th 2015 by the Swedish Species Information Centre in which 786 species of fungi are listed. Compared to the previous Red List published in 2010, 11 species have been down-listed, 51 species have been added and 35 species have changed names or taxonomic rank, thus the list has increased by 41. The changes are mainly due to increased knowledge of taxonomy, ecology and distribution, not to changes in the sta-tus of the species. Here, the members of the Species Specialist Group for Fungi 2011 – 2015 summarize the results of the red listing.

  • 291. Dahlberg, Anna-Karin
    et al.
    Bignert, Anders
    Legradi, Jessica
    Legler, Juliette
    Asplund, Lillemor
    Anthropogenic and naturally produced brominated substances in Baltic herring (Clupea harengus membras) from two sites in the Baltic Sea.2016In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 144Article in journal (Refereed)
    Abstract [en]

    In the eutrophicated Baltic Sea, several naturally produced hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have been found in marine biota. OH-PBDEs are toxic to adult and developing zebrafish and shown to be potent disruptors of oxidative phosphorylation (OXPHOS). Disturbed OXPHOS can result in altered energy metabolism and weight loss. In herring, the concentration of OH-PBDEs (i.e. 2'-OH-BDE68 and 6-OH-BDE47) has increased during the period 1980-2010 in the Baltic Proper. Over the same time period, the condition and fat content in Baltic herring have decreased. Given the toxicity and increasing trends of OH-PBDEs in Baltic herring it is important to further assess the exposure to OH-PBDEs in Baltic herring. In this study, the concentrations of OH-PBDEs and related brominated substances i.e. polybrominated phenols (PBPs), polybrominated anisoles (PBAs), methoxylated polybrominated diphenyl ethers (MeO-PBDEs) and polybrominated diphenyl ethers (PBDEs) were measured in herring sampled in the northern Baltic Proper (Askö, n = 12) and the southern Bothnian Sea (Ängskärsklubb, n = 12). The geometric mean (GM) concentrations (ng/g l.w.) at Askö and Ängskärsklubb were; Σ2PBPs: 4.3 and 9.6, Σ(2)PBAs: 34 and 20, Σ(6)OH-PBDEs: 9.4 and 10, Σ(7)MeO-PBDEs: 42 and 150, Σ(6)PBDEs: 54 and 27, respectively. 6-OH-BDE47 dominated the OH-PBDE profile and comprised 87% (Askö) and 91% (Ängskärsklubb) of the ΣOH-PBDEs. At Ängskärsklubb the mean concentration of ΣMeO-PBDEs (150 ng/g l.w.) was 15 times higher than ΣOH-PBDEs. As other fish species are known to metabolically transform MeO-PBDEs to OH-PBDEs, high levels of MeO-PBDEs can be of concern as a precursor for more toxic OH-PBDEs in herring and their roe.

  • 292.
    Dahlgren, Henrik
    et al.
    Swedish Museum of Natural History, Department of.
    Bignert, Anders
    Swedish Museum of Natural History, Department of.
    Danielsson, Sara
    Swedish Museum of Natural History, Department of.
    Faxneld, Suzanne
    Swedish Museum of Natural History, Department of.
    Kylberg, Eva
    Swedish Museum of Natural History, Department of.
    Nyberg, Elisabeth
    Swedish Museum of Natural History, Department of.
    Vasileiou, Maria
    Swedish Museum of Natural History, Department of.
    Staveley Öhlund, Jill
    Swedish Museum of Natural History, Department of.
    Berger, Urs
    Stockholm University.
    Borg, Hans
    Stockholm University.
    Eriksson, Ulla
    Stockholm University.
    Holm, Karin
    Stockholm University.
    Egebäck, Anna-Lena
    Stockholm University.
    Haglund, Peter
    Umeå University.
    Övervakning av metaller och organiska miljögifter i marin biota, 20142014Report (Other academic)
  • 293.
    Dahlin, Peter
    et al.
    Uppsala Universitet.
    Johansson, Åke
    Swedish Museum of Natural History, Department of Geology.
    Andersson, Ulf Bertil
    LKAB.
    Source character, mixing, fractionation and alkali metasomatism in Palaeoproterozoic greenstone dykes, Dannemora area, NE Bergslagen region, Sweden2014In: Geological Magazine, ISSN 0016-7568, E-ISSN 1469-5081, Vol. 151, no 4, p. 573-590Article in journal (Refereed)
    Abstract [en]

    The geochemical and isotopic characteristics of metamorphosed Svecofennian mafic dykes from the Dannemora area in the NE part of the Bergslagen region in central Sweden were investigated and compared to mafic intrusive rocks in their vicinity. The dykes, with an inferred age of c. 1860–1870 Ma, are calc-alkaline, sub-alkaline and basaltic in composition and have a mixed subduction and within-plate geochemical affinity. They are the result of mixing of at least three mantle source components with similar basaltic major element composition, but different concentrations of incompatible trace elements. Magma M1 is strongly enriched both in Rare Earth Elements (REE) and High-Field-Strength Elements (HFSE); magma M2 is highly enriched in Large-Ion Lithophile Elements (LILE, except Sr) with only moderate enrichment in HFSE and REE (particularly low in Heavy Rare Earth Elements); and magma M3 is enriched in Sr and has a flat REE profile. Magma M3 also has a somewhat more positive (depleted) initial εNd value of +1.8, compared to +0.4 to +0.5 for magmas M1 and M2. The magma evolution was controlled by a mixture of fractionation (mainly affecting the compatible elements) and mixing, best seen in the incompatible element concentrations and the Nd isotope data. The basaltic overall composition indicates little or no wholesale contamination by upper continental crust, but the dykes have undergone later metasomatic changes mainly affecting the alkali elements.

  • 294. Dalen, L
    et al.
    Elmhagen, B
    Angerbjorn, A
    DNA analysis on fox faeces and competition induced niche shifts2004In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 13, no 8, p. 2389-2392Article in journal (Refereed)
  • 295. Dalen, L
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    Fuglei, E
    Hersteinsson, P
    Kapel, C M O
    Roth, J D
    Samelius, G
    Tannerfeldt, M
    Angerbjorn, A
    Population history and genetic structure of a circumpolar species: the arctic fox2005In: Biological Journal of the Linnean Society, ISSN 0024-4066, E-ISSN 1095-8312, Vol. 84, no 1, p. 79-89Article in journal (Refereed)
  • 296. Dalen, L
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    Gotherstrom, A
    Angerbjorn, A
    Identifying species from pieces of faeces2004In: Conservation Genetics, ISSN 1566-0621, E-ISSN 1572-9737, Vol. 5, no 1, p. 109-111Article in journal (Refereed)
  • 297. Dalen, L
    et al.
    Gotherstrom, A
    Tannerfeldt, M
    Angerbjorn, A
    Is the endangered Fennoscandian arctic fox (Alopex lagopus) population genetically isolated?2002In: Biological Conservation, ISSN 0006-3207, E-ISSN 1873-2917, Vol. 105, no 2, p. 171-178, article id PII S0006-3207(01)00180-XArticle in journal (Refereed)
  • 298. Dalen, L.
    et al.
    Kvaloy, K.
    Linnell, J. D. C.
    Elmhagen, B.
    Strand, O.
    Tannerfeldt, M.
    Henttonen, H.
    Fuglei, E.
    Landa, A.
    Angerbjorn, A.
    Population structure in a critically endangered arctic fox population: does genetics matter?2006In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 15, no 10, p. 2809-2819Article in journal (Refereed)
  • 299. Dalen, Love
    et al.
    Gotherstrom, Anders
    Meijer, Tomas
    Shapiro, Beth
    Recovery of DNA from Footprints in the Snow2007In: Canadian field-naturalist, ISSN 0008-3550, Vol. 121, no 3, p. 321-324Article in journal (Refereed)
  • 300.
    Dalen, Love
    et al.
    Swedish Museum of Natural History, Department of Bioinformatics and Genetics.
    Lagerholm, Vendela K.
    Swedish Museum of Natural History, Department of Bioinformatics and Genetics.
    Nylander, Johan A. A.
    Swedish Museum of Natural History, Department of Bioinformatics and Genetics.
    Barton, Nick
    Bochenski, Zbigniew M.
    Tomek, Teresa
    Rudling, David
    Ericson, Per G. P.
    Swedish Museum of Natural History, Department of Bioinformatics and Genetics. Swedish Museum of Natural History, Research Division.
    Irestedt, Martin
    Swedish Museum of Natural History, Department of Bioinformatics and Genetics.
    Stewart, John R.
    Identifying Bird Remains Using Ancient DNA Barcoding2017In: Genes, ISSN 2073-4425, E-ISSN 2073-4425, Vol. 8, no 6, article id 169Article in journal (Refereed)
3456789 251 - 300 of 2121
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