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  • 151.
    Bosi, Ferdinando
    Swedish Museum of Natural History, Department of Geology.
    Bond valence at mixed occupancy sites. I. Regularpolyhedra2014In: ACTA CRYSTALLOGRAPHICA. SECTION B, STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS, ISSN 2052-5206, Vol. 70, p. 864-870Article in journal (Refereed)
  • 152.
    Bosi, Ferdinando
    Swedish Museum of Natural History, Department of Geology.
    Mean bond length variation in crystal structures: a bond valence approach2014In: ACTA CRYSTALLOGRAPHICA. SECTION B, STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS, ISSN 2052-5206, Vol. 70, p. 697-704Article in journal (Refereed)
  • 153.
    Bosi, Ferdinando
    et al.
    Sapienza Università di Roma.
    Andreozzi, Giovanni B.
    Sapienza Università di Roma.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Zn-O tetrahedral bond length variations in normal spinel oxides2011In: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 96, p. 594-598Article in journal (Refereed)
  • 154.
    Bosi, Ferdinando
    et al.
    Università di Roma, Italien.
    Andreozzi, Giovanni
    Università di Roma, Italien.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Experimental evidence for partial Fe2+ disorder at the Y and Z sites of tourmaline: a combined EMP, SREF, MS, IR and OAS study of schorl2015In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 79, no 3, p. 515-528Article in journal (Refereed)
  • 155.
    Bosi, Ferdinando
    et al.
    Sapienza Università di Roma, Italy.
    Christy, Andrew
    Australian National University, Canberra, Australia.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Crystal-chemical aspects of the roméite group, A2Sb2O6Y, of the pyrochlore supergroup2017In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 81, no 6, p. 1287-1302Article in journal (Refereed)
    Abstract [en]

    Four specimens of the roméite-group minerals oxyplumboroméite and fluorcalcioroméite from the Långban Mn-Fe deposit in Central Sweden were structurally and chemically characterized by single-crystal X-ray diffraction, electron microprobe analysis and infrared spectroscopy. The data obtained and those on additional roméite samples from literature show that the main structural variations within the roméite group are related to variations in the content of Pb2+, which is incorporated into the roméite structure via the substitution Pb2+ → A2+ where A2+ = Ca, Mn and Sr. Additionally, the cation occupancy at the six-fold coordinated B site, which is associated with the heterovalent substitution BFe3+ + Y□ → BSb5+ + YO2–, can strongly affect structural parameters.

    Chemical formulae of the roméite minerals group are discussed. According to crystal-chemical information, the species associated with the name ‘kenoplumboroméite’, hydroxycalcioroméite and fluorcalcioroméite most closely approximate end-member compositions Pb2(SbFe3+)O6□, Ca2(Sb5+Ti)O6(OH) and (CaNa)Sb2O6F, respectively. However, in accord with pyrochlore nomenclature rules, their names correspond to multiple end-members and are best described by the general formulae: (Pb,#)2(Sb,#)2O6□, (Ca,#)2(Sb,#)2O6(OH) and (Ca,#)Sb2(O,#)6F, where ‘#’ indicates an unspecified charge-balancing chemical substituent, including vacancies.

  • 156.
    Bosi, Ferdinando
    et al.
    Sapienza Università di Roma, Italy.
    Cámara, Fernando
    Università di Torino, Italy.
    Ciriotti, Marco
    Associazione Micromineralogica Italiana, Torino, Italy.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Reznitskii, Leonid
    Russian Academy of Science, Irkutsk, Russia.
    Stagno, Vincenzo
    Sapienza Università di Roma, Italy.
    Crystal-chemical relations and classification problems in tourmalines belonging to the oxy-schorl—oxy-dravite—bosiite—povondraite series2017In: European journal of mineralogy, ISSN 0935-1221, E-ISSN 1617-4011, Vol. 29, no 3, p. 445-455Article in journal (Refereed)
  • 157.
    Bosi, Ferdinando
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Henrik, Skogby
    Swedish Museum of Natural History, Department of Geology.
    Oxy-dravite, Na(Al2Mg)(Al5Mg)(Si6O18)(BO3)3(OH)3O, a new mineral species of the tourmaline supergroup2013In: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 98, p. 1442-1448Article in journal (Refereed)
  • 158.
    Bosi, Ferdinando
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Andreozzi, Giovanni B.
    Sapienza Università di Roma.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Lucchesi, Sergio
    Sapienza Università di Roma.
    Structural refinement of Mn-doped spinel: a case for tetrahedrally coordinated Mn3+ in an oxygen-based structure2007In: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 92, p. 27-33Article in journal (Refereed)
  • 159.
    Bosi, Ferdinando
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    D'Ippolito, Veronica
    Sapienza Università di Roma.
    Andreozzi, Giovanni B.
    Sapienza Università di Roma.
    Blue spinel crystals in the MgAl2O4-CoAl2O4 series: II. Cation ordering over short range and long range scales2012In: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 97, p. 1834-1840Article in journal (Refereed)
  • 160.
    Bosi, Ferdinando
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Crystal chemistry of the magnetite-ulvöspinel series2009In: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 94, p. 181-189Article in journal (Refereed)
  • 161.
    Bosi, Ferdinando
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Crystal chemistry of the MgAl2O4-MgMn2O4-MnMn2O4 system: Analysis of structural distortion in spinel and hausmannite-type structures2010In: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 95, p. 602-607Article in journal (Refereed)
  • 162.
    Bosi, Ferdinando
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Crystal chemistry of the ulvöspinel-qandilite series2014In: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 99, p. 847-851Article in journal (Refereed)
  • 163.
    Bosi, Ferdinando
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Stoichiometry of synthetic ulvöspinel single crystals2008In: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 93, p. 1312-1316Article in journal (Refereed)
  • 164.
    Bosi, Ferdinando
    et al.
    Sapienza Università di Roma, Italy.
    Naitza, Stefano
    Università degli Studi di Cagliari, Italy.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Secchi, Francesco
    Università degli Studi di Sassari, Italy.
    Conte, Aida M.
    CNR-Istituto di Georiscienze e Georisose, Rome, Italy.
    Cuccuru, Stafano
    Università degli Studi di Sassari.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    De La Rosa, Nathaly
    Division of Nuclear Physics, Lund University.
    Kristiansson, Per
    Division of Nuclear Physics, Lund University.
    Nilsson, E.J. Charlotta
    Division of Nuclear Physics, Lund University.
    Ros, Linus
    Division of Nuclear Physics, Lund University.
    Andreozzi, Giovanni B.
    Sapienza Università di Roma, Italy.
    Late magmatic controls on the origin of schorlitic and foititic tourmalines from late-Variscan peraluminous granites of the Arbus pluton (SW Sardinia, Italy): Crystal-chemical study and petrological constraints2018In: Lithos, ISSN 0024-4937, E-ISSN 1872-6143, Vol. 308-309, p. 395-411Article in journal (Refereed)
    Abstract [en]

    Tourmalines from the late-Variscan Arbus pluton (SWSardinia) and its metamorphic aureole were structurally and chemically characterized by single-crystal X-ray diffraction, electron and nuclear microprobe analysis, Mössbauer, infrared and optical absorption spectroscopy, to elucidate their origin and relationships with the magmatic evolution during the pluton cooling stages. The Arbus pluton represents a peculiar shallow magmatic system, characterized by sekaninaite (Fe-cordierite)-bearing peraluminous granitoids, linked via AFC processes to gabbroic mantle-derived magmas. The Fe2+-Al-dominant tourmalines occur in: a) pegmatitic layers and pods, as prismatic crystals; b) greisenized rocks and spotted granophyric dikes, as clots or nests of fine-grained crystals in small miaroles locally forming orbicules; c) pegmatitic veins and pods close to the contacts within the metamorphic aureole. Structural formulae indicate that tourmaline in pegmatitic layers is schorl, whereas in greisenized rocks it ranges fromschorl to fluor-schorl. Tourmalines in thermometamorphosed contact aureole are schorl, foitite and Mg-rich oxy-schorl. The main substitution is Na+Fe2+↔▢+Al, which relates schorl to foitite. The homovalent substitution (OH)F at the O1 crystallographic site relates schorl to fluor-schorl, while the heterovalent substitution Fe2++(OH, F)Al+O relates schorl/fluor-schorl to oxy-schorl. Tourmaline crystallization in the Arbus pluton was promoted by volatile (B, F and H2O) enrichment, low oxygen fugacity and Fe2+ activity. The mineralogical evolutive trend is driven by decreasing temperature, as follows: sekaninaite+quartz →schorl+quartz→fluor-schorl+quartz → foitite+quartz. The schorl→foitite evolution represents a distinct trend towards (Al+!) increase and unit-cell volumedecrease. These trends are typical of granitic magmas and consistent with Li-poor granitic melts, as supported by the absence of elbaite and other Li-minerals in the Arbus pluton. Tourmaline-bearing rocks reflect the petrogenetic signi!cance of contribution from a metapelitic crustal component during the evolution of magmas in the middle-upper crust.

  • 165.
    Bosi, Ferdinando
    et al.
    Sapienza Università di Roma, Italy.
    Reznitskii, Leonid
    Russian Academy of Science, Irkutsk, Russia.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Crystal chemistry of Al-V-Cr oxy-tourmalines from Sludyanka complex, Lake Baikal, Russia2017In: European journal of mineralogy, ISSN 0935-1221, E-ISSN 1617-4011, Vol. 29, no 3, p. 457-472Article in journal (Refereed)
  • 166.
    Bosi, Ferdinando
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Reznitskii, Leonid
    Russian Academy of Science.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Vanadio-oxy-chromium-dravite, NaV3(Cr4Mg2)(Si6O18)(BO3)3(OH)3O, a new mineral species of the tourmaline supergroup 2014In: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 99, p. 1155-1162Article in journal (Refereed)
  • 167.
    Bosi, Ferdinando
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Reznitskii, Leonid
    Russian Academy of Science, Irkutsk.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Vanadio-oxy-dravite, NaV3(Al4Mg2)(Si6O18)(BO3)3(OH)3O, a new mineral species of the tourmaline supergroup2014In: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 99, p. 218-224Article in journal (Refereed)
  • 168.
    Bosi, Ferdinando
    et al.
    Sapienza Università di Roma, Italy.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Fregola, Rosa Anna
    Università di Bari Aldo Moro, Italy.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Crystal chemistry of spinels in the system MgAl2O4-MgV2O4-Mg2VO42016In: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 101, p. 580-586Article in journal (Refereed)
    Abstract [en]

    Eight spinel single-crystal samples belonging to the spinel sensu stricto-magnesiocoulsonite series (MgAl2O4-MgV2O4) were synthesized and crystal-chemically characterized by X‑ray diffraction, electron microprobe and optical absorption spectroscopy. Site populations show that the tetrahedrally coordinated site (T) is populated by Mg and minor Al for the spinel sensu stricto compositions, and only by Mg for the magnesiocoulsonite compositions, while the octahedrally coordinated site (M) is populated by Al, V3+, minor Mg, and very minor amounts of V4+. The latter occurs in appreciable amounts in the Al-free magnesium vanadate spinel, T(Mg)M(Mg0.26V3+1.48V4+0.26)O4, showing the presence of the inverse spinel VMg2O4. The studied samples are characterized by substitution of Al3+ for V3+ and (Mg2++V4+) for 2V3+ described in the system MgAl2O4-MgV2O4-VMg2O4.

    The present data in conjunction with data from the literature provide a basis for quantitative analyses of two solid-solution series MgAl2O4-MgV23+O4 and MgV23+O4-V4+Mg2O4. Unit-cell parameter increases with increasing V3+ along the series MgAl2O4-MgV2O4 (8.085–8.432 Å), but only slightly increases with increasing V3+ along the series VMg2O4-MgV2O4 (8.386–8.432 Å). Although a solid solution could be expected between the MgAl2O4 and VMg2O4 end-members, no evidence was found. Amounts of V4+ are nearly insignificant in all synthetic Al-bearing vanadate spinels, but are appreciable in Al-free vanadate spinel.

    An interesting observation of the present study is that despite the observed complete solid-solution along the MgAl2O4-MgV2O4 and MgV2O4-VMg2O4 series, the spinel structure seems to be unable to stabilize V4+ in any intermediate members on the MgAl2O4-Mg2VO4 join even at high oxygen fugacities. This behavior indicates that the accommodation of specific V-valences can be strongly influenced by crystal-structural constraints, and any evaluation of oxygen fugacities during mineral formation based exclusively on V cation valence distributions in spinel should be treated with caution. The present study underlines that the V valency distribution in spinels is not exclusively reflecting oxygen fugacities, but also depends on activities and solubilities of all chemical components in the crystallization environment.

  • 169.
    Bosi, Ferdinando
    et al.
    Sapienza Università di Roma, Italy.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Oxy-foitite, □(Fe2+Al2)Al6(Si6O18)(BO3)3(OH)3O, a new mineral species of the tourmaline supergroup2017In: European journal of mineralogy, ISSN 0935-1221, E-ISSN 1617-4011, Vol. 29, no 5, p. 889-896Article in journal (Refereed)
    Abstract [en]

    Oxy-foitite, □(Fe2+Al2)Al6(Si6O18)(BO3)3(OH)3O, is a new mineral of the tourmaline supergroup. It occurs in high-grade migmatitic gneisses of pelitic composition at the Cooma metamorphic Complex (New South Wales, Australia), in association with muscovite, K-feldspar and quartz. Crystals are black with a vitreous luster, sub-conchoidal fracture and gray streak. Oxy-foitite has a Mohs hardness of ∼7, and has a calculated density of 3.143 g/cm3. In plane-polarized light, oxy-foitite is pleochroic (O= dark brown and E = pale brown), uniaxial negative. Oxy-foitite belongs to the trigonal crystal system, space group R3ma = 15.9387(3) Å, c = 7.1507(1)Å and V = 1573.20(6)Å3,Z = 3. The crystal structure of oxy-foitite was refined to R1 = 1.48% using 3247 unique reflections from single-crystal X-ray diffraction using MoKα radiation. Crystal-chemical analysis resulted in the empirical structural formula: X(□0.53Na0.45Ca0.01K0.01)Σ1.00Y(Al1.53Fe2+1.16Mg0.22Mn2+0.05Zn0.01Ti4+0.03)Σ3.00Z(Al5.47Fe3+0.14Mg0.39)Σ6.00[(Si5.89Al0.11)Σ6.00O18](BO3)3V(OH)3W[O0.57F0.04(OH)0.39]Σ1.00. Oxy-foitite belongs to the X-site vacant group of the tourmaline-supergroup minerals, and shows chemical relationships with foitite through the substitution YAl3++WO2-YFe2++W(OH)1–.

  • 170.
    Bosi, Ferdinando
    et al.
    Sapienza Università di Roma, Rome, Italy.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Thermally induced cation redistribution in Fe‑bearing oxy‑dravite and potential geothermometric implications2016In: Contributions to Mineralogy and Petrology, ISSN 0010-7999, E-ISSN 1432-0967, Vol. 171, no 5, p. 1-14, article id 47Article in journal (Refereed)
    Abstract [en]

    Iron-bearing oxy-dravite was thermally treated in air and hydrogen atmosphere at 800 °C to study potential changes in Fe, Mg and Al ordering over the octahedrally coordinated Y and Z sites and to explore possible applications to intersite geothermometry based on tourmaline. Overall, the experimental data (structural refinement, Mössbauer, infrared and optical absorption spectroscopy) show that heating Fe-bearing tourmalines results in disordering of Fe over Y and Z balanced by ordering of Mg at Y, whereas Al does not change appreciably. The Fe disorder depends on temperature, but less on redox conditions. The degree of Fe3+–Fe2+ reduction is limited despite strongly reducing conditions, indicating that the fO2 conditions do not exclusively control the Fe oxidation state at the present experimental conditions. Untreated and treated samples have similar short- and long-range crystal structures, which are explained by stable Al-extended clusters around the O1 and O3 sites. In contrast to the stable Al clusters that preclude any temperature-dependent Mg–Al order– disorder, there occurs Mg diffusion linked to temperaturedependent exchange with Fe. Ferric iron mainly resides around O2− at O1 rather than (OH), but its intersite disorder induced by thermal treatment indicates that Fe redistribution is the driving force for Mg–Fe exchange and that its diffusion rates are significant at these temperatures. With increasing temperature, Fe progressively disorders over Y and Z, whereas Mg orders at Y according to the order–disorder reaction: YFe + ZMg → ZFe + YMg. The presented findings are important for interpretation of the post-crystallization history of both tourmaline and tourmaline host rocks and imply that successful tourmaline geothermometers may be developed by thermal calibration of the Mg– Fe order–disorder reaction, whereas any thermometers based on Mg–Al disorder will be insensitive and involve large uncertainties.

  • 171.
    Bosi, Ferdinando
    et al.
    Sapienza Università di Roma, Italy.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Ciriotti, Marco
    Associazione Micromineralogica Italiana,Torino, Italy.
    Experimental cation redistribution in the tourmaline lucchesiite, CaFe2+3Al6(Si6O18)(BO3)3(OH)3O2018In: Physics and chemistry of minerals, ISSN 0342-1791, E-ISSN 1432-2021, Vol. 45, no 7, p. 621-632Article in journal (Refereed)
    Abstract [en]

    Natural Mg-rich lucchesiite was thermally treated in air and hydrogen atmosphere up to 800 °C to study potential changes in Fe-, Mg- and Al ordering over the octahedrally coordinated Y-  and Z -sites, and to explore possible applications to intracrystalline geothermometry based on tourmaline. Overall, the experimental data (structural refinement, Mössbauer, infrared and optical absorption spectroscopy) show that thermal treatment of lucchesiite results in an increase of Fetot contents at Z balanced by an increase of Mg and Al at Y . This process is accompanied by a significant deprotonation of the O3 anion site. The Fe order–disorder reaction depends more on temperature, than on redox conditions. During heat treatment in H2 ,reduction of Fe3+ to Fe2+ was not observed despite strongly reducing conditions, indicating that the fO2  conditions do not exclusively control the Fe oxidation state at the present experimental conditions. On the basis of this and previous studies, the intersite order–disorder process induced by thermal treatment indicates that Fe redistribution is an important factor for Fe–Mg–Al-exchange and is significant at temperatures around 800 °C. As a result, Fe–Mg–Al intersite order–disorder is sensitive to temperature variations, whereas geothermometers based solely on Mg–Al order–disorder appear insensitive and involve large uncertainties. The presented findings are important for interpretation of the post-crystallization history of both tourmaline and tourmaline host rocks, and indicate that successful tourmaline geothermometers may be developed by thermal calibration of the Fe-Mg–Al order–disorder reaction.

  • 172.
    Bosi, Ferdinando
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Reznitskii, Leonid
    Russian Academy of Science, Irkutsk.
    Crystallographic and spectroscopic characterization of Fe-bearing chromo-alumino-povondraite and its relationships with oxy-chromium-dravite and oxy-dravite2013In: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 98, p. 1557-1564Article in journal (Refereed)
  • 173.
    Bosi, Ferdinando
    et al.
    Sapienza Universita di Roma.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Lazor, Peter
    Uppsala Universitet.
    Reznitskii, Leonid
    Russian Academy of Sciences.
    Atomic arrangements around the O3 site in Al- and Cr-rich oxytourmalines: a combined EMP, SREF, FTIR and Raman study2015In: Physics and chemistry of minerals, ISSN 0342-1791, E-ISSN 1432-2021, Vol. 42, p. 441-453Article in journal (Refereed)
  • 174.
    Boström, Sven
    Swedish Museum of Natural History, Department of Zoology.
    Ny biografi om Axel Ohlin2017In: Fauna och flora : populär tidskrift för biologi, ISSN 0014-8903, Vol. 112, no 3, p. 39-40Article, book review (Other (popular science, discussion, etc.))
  • 175.
    Boström, Sven
    et al.
    Swedish Museum of Natural History, Department of Zoology.
    Holovachov, Oleksandr
    Swedish Museum of Natural History, Department of Zoology.
    Description  of  a  new  species  of  Paracrobeles  Heyns,  1968  (Nematoda,   Rhabditida, Cephalobidae)  from  Kelso  Dunes,  Mojave  National   Preserve,  California,  USA2015In: European Journal of Taxonomy, ISSN 2118-­9773, Vol. 117, p. 1-11Article in journal (Refereed)
    Abstract [en]

    A new species of Paracrobeles, P. kelsodunensis sp. nov. is described from the Kelso Dunes area, Mojave National Preserve, southern California. Paracrobeles kelsodunensis sp. nov. is particularly characterised by a body length of 469–626 μm in females and 463–569 μm in males; lateral field with four incisures, extending almost to tail terminus; three pairs of asymmetrical lips, separated by U-shaped primary axils with two long guarding processes, each lip usually with four tines along its margin; three long labial probolae, deeply bifurcated, with slender prongs without tines; metastegostom with a strong anteriorly directed dorsal tooth; pharyngeal corpus anteriorly spindle-shaped, posteriorly elongate bulbous with dilated lumen; spermatheca 24–87 μm long; postvulval uterine sac 60–133 μm long; vulva in a sunken area; spicules 33–38 μm long; and male tail with a 5–8 μm long mucro. The generic diagnosis is emended on the basis of recently described species and a key to the species of Paracrobeles is provided.

  • 176.
    Boström, Sven
    et al.
    Swedish Museum of Natural History, Department of Zoology.
    Holovachov, Oleksandr
    Swedish Museum of Natural History, Department of Zoology.
    Description of Drilocephalobus moldavicus Lisetskaya,1968 (Rhabditida: Osstellidae) from Kelso Dunes, Mojave National Reserve, California,USA2018In: Zootaxa, ISSN 1175-5326, E-ISSN 1175-5334, Vol. 4514, no 3, p. 438-444Article in journal (Refereed)
  • 177.
    Boström, Sven
    et al.
    Swedish Museum of Natural History, Department of Zoology.
    Holovachov, Oleksandr
    Swedish Museum of Natural History, Department of Zoology.
    Descriptions of species of Stegelleta Thorne, 1938 (Nematoda, Rhabditida, Cephalobidae) from California, New Zealand and Senegal, and a revision of the genus2014In: European Journal of Taxonomy, ISSN 2118-9773, Vol. 87, p. 1-19Article in journal (Refereed)
    Abstract [en]

    Populations of Stegelleta are described from California, New Zealand and Senegal. An amphimictic population from California is identified as belonging to S. incisa and compared with type specimens from Utah and an amphimictic population from Italy. One population from New Zealand is close to S. incisa but considered to represent a new species, Stegelleta laterocornuta sp. nov. It is particularly characterised by a 379–512 μm long body in females and 365–476 μm in males; cuticle divided into 16 rows of blocks at midbody (excluding lateral field); lateral field with four incisures; three pairs of asymmetrical lips, U-shaped primary axils without guarding processes, each lip asymmetrically rectangular with a smooth margin, only lateral lips have slender acute tines; three labial probolae, bifurcated at half of their length; vulva without flap; spermatheca 17–31 μm long; postuterine sac 7–24 μm long; spicules 21.5–23.5 μm long. Other specimens from New Zealand are identified as belonging to S. tuarua. A parthenogenetic population from Senegal is identified as belonging to S. ophioglossa and compared with type specimens from Mongolia and records of several other populations of S. ophioglossa. The generic diagnosis is emended and a key to the species of Stegelleta is provided.

  • 178.
    Boström, Sven
    et al.
    Swedish Museum of Natural History, Department of Zoology.
    Holovachov, Oleksandr
    Swedish Museum of Natural History, Department of Zoology.
    The Swedish marine nematologist Carl Allgén (1886–1960): a bio-bibliography and his collection2017In: Zootaxa, ISSN 1175-5326, E-ISSN 1175-5334, Vol. 4232, no 4, p. 451-490Article in journal (Refereed)
  • 179.
    Bouchal, Johannes M.
    Swedish Museum of Natural History, Department of Paleobiology.
    Zetter, Reinhard (Contributor)
    Pollen and spores of the uppermost Eocene Florissant Formation, Colorado: A combined light and scanning electron microscopy study2016In: Grana, Vol. 55, no 3, p. 179-245Article in journal (Refereed)
    Abstract [en]

    The uppermost Eocene Florissant Formation, Rocky Mountains, Colorado, has yielded numerous insect, vertebrate, and plant fossils. Three previous comprehensive palynological studies investigated sections of lacustrine deposits of the Florissant Formation and documented the response of plant communities to volcanic eruptive phases but overall found little change in plant composition throughout the investigated sections. These studies reported up to 150 pollen and spore phenotypes. In the present paper we used a taxonomic approach to the investigation of dispersed pollen and spores of the Florissant Formation. Sediment samples from the shale units containing macrofossils were investigated using light microscopy (LM) and scanning electron microscopy (SEM). The general picture of the palynoflora is in agreement with previous studies. However, the combined LM and SEM investigation provides important complementary information to previous LM studies. While a fairly large amount of previous pollen determinations could be confirmed, the purported taxonomic affinities of several pollen phenotypes need to be revised. For example, pollen referred to as Podocarpus or Podocarpidites sp. belongs to the Pinaceae Cathaya, Malus/Pyrus actually belongs to Dryadoideae, pollen of the form genus Boehlensipollis referred to as Proteaceae/Sapindaceae/Elaeagnaceae or Cardiospermum belongs to Sapindaceae but not to Cardiospermum, and pollen of Persicarioipollis sp. B with previously assumed affinities to Polygonaceae actually belongs to Thymelaeaceae. Pandaniidites and one type of Malvacipollis cannot be linked with Pandanaceae and Malvaceae. A few taxa are new records for Florissant (Ebenaceae: Diospyros; Mernispermaceae; Trochodendraceae: Tetracentron). In general, SEM investigations complement the LM palynological studies and improve the identification of dispersed pollen and spores and enable integration of data from dispersed fossil pollen into a wide range of comparative morphological, taxonomic, evolutionary, biogeographic, and phylogenetic studies.

  • 180.
    Bouchal, Johannes M.
    Swedish Museum of Natural History, Department of Paleobiology.
    The middle Miocene palynofloras of the Salihpaşalar lignite mine (Yatağan Basin, southwest Anatolia): environmental characterisationand comparison with palynofloras from adjacent basins2019In: Palaeobiodiversity and Palaeoenvironments, ISSN 1867-1594, E-ISSN 1867-1608Article in journal (Refereed)
    Abstract [en]

    As the third part of an ongoing investigation of middle Miocene palynofloras in the Yatağan Basin (YB), southwestern Anatolia, thepalynofloras of the Salihpaşalar lignite mine in the main YB were studied. Seven types of algal spores, aplanospores/zygospores orcysts, six types of lycophyte and fern spores, 12 types of gymnosperm pollen and 90 types of angiosperm pollen were identified. Of atotal of ca. 140 plant taxa described from the YB, over 10% are confined to the Salihpaşalar assemblage. Differences between coevalpalynofloras of the Sekköy Member might reflect changing or prograding depositional environments. A number of rare accessorialtaxa reflect these local differences: Pilularia, Valeriana, Drosera and Persicaria aff. amphibia only occur at Salihpaşalar and aretypical of shallow water or temporary ponds associated with a lake shore. Apart from this, all the palynofloras, originating from thelignite seams and overlying limnic limestones (uppermost Turgut and Sekköy Member), of the YB are strongly indicative of extensivewoody vegetation with a dominance of diverse Fagaceae and Pinaceae. In addition, a list comparing the well-documented YBpalynomorphs to morphologically similar palynomorphs of published late early to middle Miocene plant assemblages of westernAnatolian was compiled. Such a comparison reveals that in many instances different taxon names have been used to denote the sametaxa. Hence, resolving these synonymies is a prerequisite of any meaningful comparison of palynofloras in the region.

  • 181.
    Bouchal, Johannes M.
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Denk, Thomas
    An overview of the palynoflora of the Miocene Yatağan basin, Turkey2014Conference paper (Other academic)
    Abstract [en]

    The palynoflora of the lignite strip mines of the Yatağan basin, located in the Muğla province of western Turkey, is the focus of this study. Samples were taken from the Eskihisar, Salihpasalar and Tinaz mines. In the Yatağan basin two Miocene formations, formed from river and lake deposits, Eskihisar Formation (middle Miocene) and Yatağan Formation (late Miocene) have been designated. Both show a general lithology consisting of conglomerate, sandstone, claystone, limestone and tuffite, the mined/excavated lignite bearing strata are restricted to the Eskihisar Formation.

    Until now, pollen from the Yatağan basin has mostly been described according to conventional morphological nomenclature, using light microscopy (LM) only. In this study, the same individual pollen grains are investigated by using both, LM and scanning electron microscopy (SEM). The  high resolution pictographs allow a higher taxonomic resolution.

    The rich palynoflora (Table 1) is comprised of diverse spores (at least nine morphotypes), gymnosperm pollen from Cupressaceae, Gnetales, Pinaceae, and angiosperm pollen from Poaceae, Typhaceae, Altingiaceae,  Amaranthaceae (Chenopodieae), Anacardiaceae, Apiaceae, Betulaceae, Buxaceae, Caprifoliaceae (Dipsacoideae, Lonicera) Caryophyllaceae, Compositae (Asteroideae, Cichoriodeae), Cornaceae, Eucommiaceae, Fabaceae, Fagaceae (Fagus, Quercus, Trigonobalanopsis) Geraniaceae, Juglandaceae, Malvaceae, Myricaceae, Nymphaeaceae, Oleaceae, Palmae, Plumbaginaceae (Armeria, Plumbago), Polygonaceae (Rumex), Salicaceae, Sapindaceae (Acer), Smilacaceae, and Ulmaceae (Cedrelospermum, Ulmus, Zelkova).

  • 182.
    Bouchal, Johannes M.
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Denk, Thomas
    Swedish Museum of Natural History, Department of Paleobiology.
    Grímsson, F.
    Palynostratigraphical correlation of the excavated Miocene lignite seams of the Yatağan basin (Muğla Province, south-western Turkey)2016Conference paper (Other academic)
    Abstract [en]

    The excavated main lignite seams and overlying lacustrine sediments of the opencast mines Eskihisar, Salihpaşalar, and Tınaz, Muğla Province, south-western Turkey were investigated using a high taxonomic resolution palynological approach.

    The Eskihisar section comprises 47m and 56 samples of which 30 were usable for palynological analysis. The Tınaz section comprises 75 m and 29 samples of which 15 were usable for palynological analysis. Finally, the Salihpaşalar section comprises 25 m and 26 samples of which 16 were usable for palynological analysis. The age of the palynological sections is middle to late Miocene based on radiometric dating and vertebrate fossils.

     

    In order to investigate dispersed pollen and spores and their botanical affinities a combined light microscopy and scanning electron microscopy approach was used. The rich palynoflora comprises seven types of algal cysts (Botryococcus, Zygnemataceae), seventeen spore types (Lycopsida, Marsileaceae, Osmundaceae, Pteridaceae, Polypodiaceae), 14 types of gymnosperm pollen (Ephedraceae, Cupressaceae, Pinaceae), five types of monocotyledone pollen (Poaceae, Typhaceae) and ca 90 dicotyledone pollen types (Altingiaceae, Amaranthaceae, Anacardiaceae, Apiaceae, Aquifoliaceae, Asteraceae, Betulaceae, Campanulaceae, Cannabaceae, Caprifoliaceae, Caryophyllaceae, Ericaceae, Eucommiaceae, Euphorbiaceae, Fabaceae, Fagaceae, Geraniaceae, Juglandaceae, Lamiaceae, Linaceae, Lythraceae, Malvaceae, Myricaceae, Oleaceae, Onagraceae, Plumbaginaceae, Polygonaceae, Ranunculaceae, Rosaceae, Salicaceae, Sapindaceae, Sapotaceae, Ulmaceae).

     

    The objectives of this investigation were (1) to evaluate whether the three palynological sections were deposited at the same time, and (2) to show regional vegetation differences within a single sedimentary basin.

     

    We found three general pollen zones corresponding to different sedimentary settings and palaeoenvironments. The first pollen zone was linked to lignite formation (swamp forest, fern spores, Alnus, Decodon). The second pollen zone reflects lacustrine conditions (Typhaceae) and surrounding hinterland vegetation dominated by Fagaceae. The third pollen zone is dominated by herbaceous taxa, whereas woody taxa are less diverse and less abundant.

     

    In general, the three palynological sections are congruent in reflecting distinct pollen zones. However main vegetation types may be represented by different dominating taxa (e. g. Alnus dominace in Eskihisar and Tınaz localities while absent in Salihpaşalar) and rare taxa may differ between localities.

     

    Our results demonstrate that in order to achieve a comprehensive understanding of environmental and vegetation conditions in a sedimentary basin, a single palynological section (locality) may not capture the entirety of environmental conditions and changes.

  • 183.
    Bouchal, Johannes M.
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Denk, Thomas
    Swedish Museum of Natural History, Department of Paleobiology.
    Grímsson, F.
    Zetter, Reinhard
    The middle Miocene palynoflora and palaeoenvironments of Eskihisar (Yatağan Basin, southwestern Anatolia):: a combined LM and SEM investigation2016In: Botanical journal of the Linnean Society, ISSN 0024-4074, E-ISSN 1095-8339, Vol. 182, no 1, p. 14-79Article in journal (Refereed)
    Abstract [en]

    Anatolia was a crossroads for mammal migration during the Miocene due to intermittent land connections between Africa and Anatolia and persisting warm conditions. Here, we investigated a palynological section from middle Miocene sediments of Eskihisar (southwestern Anatolia) in order to establish biogeographic links of the palynoflora and to infer the palaeoenvironment. Four algal palynomorphs, nine spore taxa, eight gymnosperms, three monocots, and 67 dicot pollen types were encountered and investigated using the “single grain method” that combines light microscopy and scanning electron microscopy. Two pollen zones reflect different phases of basin development. Zonal vegetation remained fairly stable across the section and reflects heterogeneous environments including broad-leaved deciduous forest, subtropical forest, and sclerophyllous and semi-evergreen oak forest. Conifers were accessory elements in the broad-leaved deciduous forest communities and replaced these at higher elevations. Some herbaceous taxa (Plumbaginaceae) indicate scattered occurrences of sandy and/or rocky soils. Biogeographic affinities are general Northern Hemispheric, North American, and East Asian as also suggested by the macro fossil record. Only two taxa provide potential biogeographic links with the African flora. This suggests that biome shifts of plant taxa between African subtropical /tropical biomes and Anatolian (western Eurasian) temperate forests and shrublands may have been rare in the middle Miocene.

  • 184.
    Bouchal, Johannes M.
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Grímsson, F.
    Zetter, Reinhard
    Denk, Thomas
    Swedish Museum of Natural History, Department of Paleobiology.
    Some new pollen taxa from the middle Miocene of south western Anatolia2016Conference paper (Other academic)
    Abstract [en]

    In an ongoing study, focussing on the plant fossils and palynofloras of the lignite strip mines of the Yatağan basin(Muğla province), a number of pollen taxa, previously not reported from middle Miocene terrestrial sediments of Anatolia were encountered.

  • 185.
    Bouchal, Johannes M.
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Güner, Tuncay H.
    Swedish Museum of Natural History, Department of Paleobiology. Faculty of Forestry, Department of Forest Botany, Istanbul University Cerrahpa¸sa, 34473 Bahçeköy, Istanbul, Turkey.
    Denk, Thomas
    Swedish Museum of Natural History, Department of Paleobiology.
    Middle Miocene climate of southwestern Anatolia from multiple botanical proxies2018In: Climate of the Past Discussions, ISSN 1814-9340, E-ISSN 1814-9359, Vol. 14, p. 1427-1440Article in journal (Other academic)
    Abstract [en]

    The middle Miocene climate transition (MMCT) was a phase of global cooling possibly linked to decreasing levels of atmospheric CO2. The MMCT coincided with the European  Mammal Faunal Zone MN6. From this time, important biogeographic links between Anatolia  and eastern Africa include the hominid Kenyapithecus. Vertebrate fossils suggested mixed  open and forested landscapes under (sub)tropical seasonal climates for Anatolia. Here, we  infer the palaeoclimate during the MMCT and the succeeding cooling phase for a middle Miocene (14.8–13.2 Ma) of an intramontane basin in southwestern Anatolia using three2palaeobotanical proxies: (i) Köppen signatures based on the nearest-living-relative principle. (ii) Leaf physiognomy analysed with the Climate Leaf Analysis Multivariate Program (CLAMP). (iii) Genus-level biogeographic affinities of fossil floras with modern regions. The three proxies reject tropical climates for the MMCT of southwestern Anatolia and instead infer warm temperate C climates. Köppen signatures reject summer-dry Cs climates but cannot discriminate between fully humid Cf and winter-dry Cw; CLAMP reconstructs Cf climate based on the low X3.wet/X3.dry ratio. Additionally, we assess whether the palaeobotanical record does resolve transitions from the warm Miocene Climatic Optimum (MCO, 16.8–14.7 Ma) into the MMCT (14.7–13.9 Ma), and a more pronounced cooling at 13.9–13.8 Ma, as reconstructed from benthic stable isotope data. For southwestern Anatolia, we find that arboreal taxa predominate in MCO floras (MN5), whereas in MMCT floras (MN6) abundances of arboreal and non-arboreal elements strongly fluctuate indicating higher structural complexity of the vegetation. Our data show a distinct pollen zone between MN6 and MN7+8 dominated by herbaceous taxa. The boundary MN6 and MN7+8, roughly corresponding to a first abrupt cooling at 13.9–13.8 Ma, possibly might be associated with this herb-rich pollen zone.

  • 186.
    Bouchal, Johannes M.
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Güner, Tuncay H.
    Denk, Thomas
    Swedish Museum of Natural History, Department of Paleobiology.
    Palynological and palaeobotanical investigations in the Miocene Yatağan basin, Turkey: High-resoluton taxonomy and biostratigraphy2015Conference paper (Other academic)
    Abstract [en]

    The subject of this study is the palynology (biostratigraphic and taxonomic) and the plant remains of the lignite strip mines of Eskihisar, Salihpasalar, and Tinaz (Muğla province, western Turkey). In the Yatağan basin two Miocene to Pliocene formations are present, the Eskihisar Formation (early to middle Miocene) and the Yatağan Formation (late Miocene to early Pliocene). Both formations represent river and lake deposits consisting mainly of conglomerate, sandstone, claystone, limestone, tuffite, and intercalated lignite; the thickest, actively mined lignite seams occur in the Sekköy member of the Eskihisar Formation.

    Previous palynological studies of the palynoflora of the Yatağan basin mainly focussed on its biostratigraphic and palaeoclimatic significance, using conventional morphological nomenclature and light microscopy (LM).

    In this study the „single grain method“ is applied. Using this method, the same individual pollen grains are investigated by using both LM and scanning electron microscopy (SEM). The resulting high-resolution pictographs enable a much higher taxonomic resolution.

     

    The studied palynoflora is very rich and taxonomically diverse. Cryptogams are represented by more than ten spore morphotypes of at least three families (Osmundaceae, Pteridaceae, Polypodiaceae). Gymnosperm pollen is dominated by Cupressaceae, Gnetales (Ephedra), and Pinaceae (Cathaya, Keteleeria, Pinus). Angiosperm pollen can be assigned to 57 different genera belonging to Poaceae, Typhaceae, Altingiaceae, Amaranthaceae (Chenopodieae), Anacardiaceae, Apiaceae (three types), Asteraceae (Asteroideae, Cichoriodeae), Betulaceae (Alnus, Betula, Carpinus, Ostrya) Buxaceae, Campanulaceae, Caprifoliaceae (Lonicera), Caryophyllaceae, Dipsacaceae, Eucommiaceae, Euphorbiaceae, Fabaceae, Fagaceae (Fagus, Quercus, Trigonobalanopsis) Geraniaceae, Juglandaceae, Linnaceae (Linnum), Malvaceae, Myricaceae, Nymphaeaceae, Oleaceae (four different types), Plumbaginaceae (Armeria,), Polygonaceae (Rumex), Rosaceae, Sapindaceae (Acer), Ulmaceae (Cedrelospermum, Ulmus, Zelkova), and Zingiberales (Spirematospermum).

     

    In addition, more than two thousand plant macrofossils were collected in the course of repeated field trips, including remains of Pinaceae, Berberidiaceae (Mahonia), Betulaceae (Alnus, Carpinus), Buxaceae (Buxus), Fagaceae (Fagus, Quercus), Lauraceae, Malvaceae (Tilia), Myricaceae (Myrica), Rosaceae, Salicaceae (Populus, Salix), Sapindaceae (Acer), Smilacaceae (Smilax), Typhaceae (Typha), Ulmaceae (Zelkova).

     

    A combined analysis integrating these rich and diverse plant macro- and microfossil records will lead to a better understanding and refined reconstruction of the vegetation in the Yatağan basin during the middle to late Miocene.

  • 187.
    Bouchal, Johannes M.
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Mayda, Serdar
    Natural History Museum, Ege University, 35100 Izmir, Turkey.
    Zetter, Reinhard
    University of Vienna, Department of Palaeontology, Vienna, Austria.
    Grímsson, Fridgeir
    University of Vienna, Department of Palaeontology, Vienna, Austria.
    Akgün, Funda
    Dokuz Eylül University, Department of General Geology, 35210 Izmir, Turkey.
    Denk, Thomas
    Swedish Museum of Natural History, Department of Paleobiology.
    Miocene palynofloras of the Tınaz lignite mine, Muğla, southwest Anatolia: taxonomy, palaeoecology and local vegetation change2017In: Review of Palaeobotany and Palynology, ISSN 0034-6667, E-ISSN 1879-0615, Vol. 243, p. 1-36Article in journal (Refereed)
    Abstract [en]

    Middle Miocene deposits exposed at the Tınaz lignite mine, Yatağan Basin, Muğla, southwestern Turkey, were palynologically investigated. The Tınaz lignite mine section belongs to the Eskihisar Formation. The lignite seam at the base of the section represents the uppermost part of the Turgut Member. Above, c. 65 m of clayey siltstone, limestone, and marls represent the Sekköy Member. Nine spores, zygospores and cysts of fungi and algae, seven moss and fern spores, 12 gymnosperm pollen types, and more than 80 angiosperm pollen taxa were recovered from the Tınaz lignite mine section. Three pollen zones were recognized, of which pollen zone 1 corresponds to the formation of the main lignite seam and reflects the change from a fluviatile to a lacustrine depositional setting. Pollen zones 2 and 3 and a transitional zone 2-3 reflect different stages of lake development and a shift in local vegetation from forested (pollen zones 1 and 2) to more open (transitional zone 2-3, zone 3). Interpreting changes in regional vegetation from pollen zones 1 to 3 is not straightforward as changes in the pollen spectra may be affected by changing contributions of airborne and water transported pollen and spores to the observed palynoassemblages. Age inference for the Tınaz lignite mine section has been complicated by the absence of datable ash layers, associated mammal faunas, or marine sediments. However, pollen zone 3 shares key features with the pollen spectrum recovered from the nearby mammal site Yenieskihisar (upper part of Sekköy Member) for which an age of 12.5-11.2 Ma has been suggested, and to the youngest pollen zone recovered from the mammal locality Çatakbağyaka, 10 km south of Tınaz, that probably represents mammal zone MN7/8 instead of MN5 or MN6 as previously suggested. In contrast, pollen zones 1 and 2 are fairly similar to the basal parts of the Çatakbağyaka pollen flora (uppermost parts of Turgut Member, basalmost parts of Sekköy Member). Furthermore, new mammal data from the Yatağan basin suggest that the layers below pollen zone 1 are MN4/5, and that carnivores cooccuring with pollen zone 1 in the main lignite seam of Eskihisar probably belong to MN6. Hence, a Langhian to Serravallian age can be inferred for pollen zones 1 and 2 of the Tınaz lignite mine section, and a late Serravallian age for pollen zone 3. Palaeobiogeographic relationships of the palynofloras are generally northern hemispheric, with many north temperate tree taxa showing modern disjunctions East Asia- NorthAmerica (Tsuga, Carya), East Asia- western Eurasia (Zelkova), East Asia- North America- western Eurasia (Liquidambar), or restricted to East Asia (Cathaya, Eucommia) or North America (Decodon). A few taxa belong to extinct lineages that have complex biogeographic patterns (Engelhardioideae, Cedrelospermum). The presence of Picrasma (Simaroubaceae) in the lower lignite layers of pollen zone 1 is remarkable, as the botanical affinities with the enigmatic flower Chaneya present in early to middle Miocene deposits of Turkey and Central Europe have recently been shown to be with Picrasma

  • 188.
    Bouchal, Johannes Martin
    Swedish Museum of Natural History, Department of Paleobiology. University of Vienna.
    EVOLUTIONARY TRENDS AND ECOLOGICAL DIFFERENTIATION IN EARLY CENOZOIC FAGACEAE OF WESTERN NORTH AMERICA2014In: American Journal of Botany, ISSN ISSN: 0002-9122., Vol. 101, no 8, p. 1332-1349Article in journal (Refereed)
    Abstract [en]

    • Premise of the study: The early Cenozoic was a key period of evolutionary radiation in Fagaceae. The common notion is that

    species thriving in the modern summer-dry climate of California originated in climates with ample summer rain during the

    Paleogene.

    • Methods: We investigated in situ and dispersed pollen of Fagaceae from the uppermost Eocene Florissant fossil beds, Colorado,

    United States, using a combined light and scanning electron microscopy approach.

    • Key results: Pollen types of Castaneoideae with affi nities to modern Castanea , Lithocarpus , and Castanopsis were recognized.

    Pollen of the extinct genus Fagopsis represents a derived type of Castaneoideae pollen. Infrageneric groups of Quercus were

    well represented, including pollen of Group Protobalanus. The taxonomic diversity of Fagaceae and of the total plant assemblage

    indicates a mosaic of microclimates, that range from pronounced to weakly seasonal climates and depend on slope aspect

    and elevation. Continental climatic conditions may have triggered the evolution of sclerophyllous leaves and adaptive radiation

    in Quercus and other taxa thriving today under distinctly summer-dry and winter-dry climates.

    • Conclusions: Vegetation types similar to modern vegetation belts of the Coastal Ranges (chaparral, nemoral conifer forest)

    were established in the Front Range in the late Eocene. Coeval plant assemblages from the Coastal Ranges of California indicate

    distinctly subtropical, moist climates. Hence, characteristic elements found today in the summer-dry and winter-dry climates

    of Pacifi c North America ( Quercus Group Protobalanus, Notholithocarpus ) may opportunistically have dispersed into

    their modern ranges later in the Cenozoic. This scenario is in contrast to the evolution and migration patterns of their western

    Eurasian Mediterranean counterparts ( Quercus Group Ilex).

  • 189. Bouvier, Laura
    et al.
    Costa, Maria
    Connelly, James
    Jensen, Ninna
    Wielandt, Daniel
    Storey, Michael
    Nemchin, Alexander
    Whitehouse, Martin
    Swedish Museum of Natural History, Department of Geology.
    Snape, Joshua
    Swedish Museum of Natural History, Department of Geology.
    Bellucci, Jeremy
    Swedish Museum of Natural History, Department of Geology.
    Moynier, Frederic
    Agranier, Arnaud
    Gueguen, Bleuenn
    Schonbachler, Maria
    Bizzarro, Martin
    Evidence for extremely rapid magma ocean crystallization and crust formation on Mars2018In: Nature, ISSN 1476-4687, Vol. 558, p. 586-589Article in journal (Refereed)
    Abstract [en]

    The formation of a primordial crust is a critical step in the evolution of terrestrial planets but the timing of this process is poorly understood. The mineral zircon is a powerful tool for constraining crust formation because it can be accurately dated with the uranium-to-lead (U–Pb) isotopic decay system and is resistant to subsequent alteration. Moreover, given the high concentration of hafnium in zircon, the lutetium-to-hafnium (176Lu–176Hf) isotopic decay system can be used to determine the nature and formation timescale of its source reservoir (1,2,3) Ancient igneous zircons with crystallization ages of around 4,430 million years (Myr) have been reported in Martian meteorites that are believed to represent regolith breccias from the southern highlands of Mars (4,5) These zircons are present in evolved lithologies interpreted to reflect re-melted primary Martian crust4, thereby potentially providing insight into early crustal evolution on Mars. Here, we report concomitant high-precision U–Pb ages and Hf-isotope compositions of ancient zircons from the NWA 7034 Martian regolith breccia. Seven zircons with mostly concordant U–Pb ages define 207Pb/206Pb dates ranging from 4,476.3 ± 0.9 Myr ago to 4,429.7 ± 1.0 Myr ago, including the oldest directly dated material from Mars. All zircons record unradiogenic initial Hf-isotope compositions inherited from an enriched, andesitic-like crust extracted from a primitive mantle no later than 4,547 Myr ago. Thus, a primordial crust existed on Mars by this time and survived for around 100 Myr before it was reworked, possibly by impacts (4,5) to produce magmas from which the zircons crystallized. Given that formation of a stable primordial crust is the end product of planetary differentiation, our data require that the accretion, core formation and magma ocean crystallization on Mars were completed less than 20 Myr after the formation of the Solar System. These timescales support models that suggest extremely rapid magma ocean crystallization leading to a gravitationally unstable stratified mantle, which subsequently overturns, resulting in decompression melting of rising cumulates and production of a primordial basaltic to andesitic crust (6,7).

  • 190. Brace, Selina
    et al.
    Thomas, Jessica A.
    Dalén, Love
    Swedish Museum of Natural History, Department of Bioinformatics and Genetics.
    Burger, Joachim
    MacPhee, Ross D. E.
    Barnes, Ian
    Turvey, Samuel T.
    Evolutionary History of the Nesophontidae, the Last Unplaced Recent Mammal Family2016In: Molecular biology and evolution, ISSN 0737-4038, E-ISSN 1537-1719, Vol. 33, no 12, p. 3095-3103Article in journal (Refereed)
    Abstract [en]

    The mammalian evolutionary tree has lost several major clades through recent human-caused extinctions. This process of historical biodiversity loss has particularly affected tropical island regions such as the Caribbean, an area of great evolutionary diversification but poor molecular preservation. The most enigmatic of the recently extinct endemic Caribbean mammals are the Nesophontidae, a family of morphologically plesiomorphic lipotyphlan insectivores with no consensus on their evolutionary affinities, and which constitute the only major recent mammal clade to lack any molecular information on their phylogenetic placement. Here, we use a palaeogenomic approach to place Nesophontidae within the phylogeny of recent Lipotyphla. We recovered the near-complete mitochondrial genome and sequences for 17 nuclear genes from a similar to 750-year-old Hispaniolan Nesophontes specimen, and identify a divergence from their closest living relatives, the Solenodontidae, more than 40 million years ago. Nesophontidae is thus an older distinct lineage than many extant mammalian orders, highlighting not only the role of island systems as "museums" of diversity that preserve ancient lineages, but also the major human-caused loss of evolutionary history.

  • 191. Brantberg, Krister
    et al.
    Babak, F.
    Kalthoff, Daniela
    Swedish Museum of Natural History, Department of Zoology.
    Do extant elephants have superior canal dehiscence syndrome?2015In: Acta Oto-Laryngologica, ISSN 0001-6489, E-ISSN 1651-2251Article in journal (Refereed)
  • 192. Brazilian Flora Group, The
    et al.
    Santos, Karin
    Swedish Museum of Natural History, Department of Botany.
    Brazilian Flora 2020: Innovation and collaboration to meet Target 1 of the Global Strategy for Plant Conservation (GSPC).: Brazilian Flora 20202018In: Rodriguésia, ISSN 0370-6583, Vol. 69, no 4, p. 1513-1527Article in journal (Refereed)
    Abstract [en]

    The Global Strategy for Plant Conservation (GSPC) was established by the Conference of Parties in 2002 todecrease the loss of plant diversity, reduce poverty and contribute to sustainable development. To achieve thisoverarching goal, the GSPC has established a series of targets, one of which is to ensure that plant diversity iswell understood, so that it can be effectively conserved and used in a sustainable manner. Brazil hosts morethan 46,000 species of plants, algae and fungi, representing one of the most biodiverse countries on Earth, andplaying a key role in the GSPC. To meet the GSPC goals of Target 1 and facilitate access to plant diversity,Brazil committed to preparing the List of Species of the Brazilian Flora (2008–2015) and the Brazilian Flora2020 (2016–present). Managing all the information associated with such great biodiversity has proven to be anextremely challenging task. Here, we synthesize the history of these projects, focusing on the multidisciplinaryand collaborative approach adopted to develop and manage the inclusion of all the knowledge generated thoughdigital information systems. We further describe the methods used, challenges faced, and strategies adopted, aswell as summarize advances to date and prospects for completing the Brazilian flora in 2020.Key words: database, diversity, hotspots, taxonomy.

  • 193. Brengman, L.
    et al.
    Fedo, C.M.
    Whitehouse, Martin J.
    Swedish Museum of Natural History, Department of Geology.
    Micro-scale silicon isotope heterogeneity observed in hydrothermal quartz precipitates from the >3.7 Ga Isua Greenstone Belt, SW Greenland.2016In: Terra Nova, ISSN 0954-4879, E-ISSN 1365-3121, Vol. 28, p. 70-75Article in journal (Refereed)
    Abstract [en]

    Pillow basalt and chert form integral lithologies comprising many Archean greenstone belt packages. To investigate details of these lithologies in the >3.7 Ga Isua Greenstone Belt, SW Greenland, we measured silicon isotope compositions of quartz crystals, by secondary ion mass spectrometry, from a quartz-cemented, quartz-amygdaloidal basaltic pillow breccia, recrystallized chert and chert clasts thought to represent silica precipitation under hydrothermal conditions. The recrystallized chert, chert clasts and quartz cement have overlapping δ30Si values, while the δ30Si values of the quartz amygdules span nearly the entire range of previously published values for quartz precipitates of any age, despite amphibolite facies metamorphism. We suggest that the heterogeneity is derived from kinetic isotope fractionation during quartz precipitation under disequilibrium conditions in a hydrothermal setting, consistent with the pillow breccia origin. On the basis of the present data, we conclude that the geological context of each sample must be carefully evaluated when interpreting δ30Si values of quartz.

  • 194.
    Britzke, Ricardo
    et al.
    Universidade Estadual Paulista.
    Oliveira, Claudio
    Universidade Estadual Paulista.
    Kullander, Sven
    Swedish Museum of Natural History, Department of Zoology.
    Apistogramma ortegai (Teleostei: Cichlidae), a new species of cichlid fish from the Ampyiacu River in the Peruvian Amazon basin2014In: Zootaxa, ISSN 1175-5326, E-ISSN 1175-5334, Vol. 3869, no 4, p. 409-419Article in journal (Refereed)
    Abstract [en]

    Apistogramma ortegai, new species, is described from small streams tributaries of the Ampiyacu River near Pebas, in easternPeru. It belongs to the Apistogramma regani species group and is distinguished from all other species of Apistogrammaby the combination of contiguous caudal spot to bar 7, presence of abdominal stripes, short dorsal-fin lappets in both sexes,absence of vertical stripes on the caudal fin, and reduced number of predorsal and prepelvic scales.

  • 195.
    Bruschini, Enrico
    et al.
    Sapienza Università di Roma.
    Speziale, Sergio
    Geoforschungszentrum, Potsdam.
    Andreozzi, Giovanni
    Sapienza Università di Roma.
    Bosi, Ferdinando
    Sapienza Università di Roma.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    The elasticity of MgAl2O4-MnAl2O4 spinels by Brillouin scattering and an empirical approach for bulk modulus prediction2015In: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 100, p. 644-651Article in journal (Refereed)
  • 196. Buchbender, Volker
    et al.
    Hespanhol, Helena
    Krug, Michael
    Sérgio, Cecília
    Séneca, Ana
    Maul, Karola
    Hedenäs, Lars
    Swedish Museum of Natural History, Department of Botany.
    Quandt, Dietmar
    Phylogenetic reconstructions of the Hedwigiaceae reveal cryptic speciation and hybridisation in Hedwigia2014In: Bryophyte Diversity and Evolution, ISSN 2381-9677, Vol. 36, p. 1-21Article in journal (Refereed)
  • 197. Budd, D.A.
    et al.
    Troll, V.R.
    Deegan, F.M.
    Jolis, E.M.
    Smith, V.C.
    Whitehouse, Martin J.
    Swedish Museum of Natural History, Department of Geology.
    Harris, C.
    Freda, C.
    Hilton, D.R.
    Halldorsson, S.A.
    Bindemann, I.N.
    Magma reservoir dynamics at Toba caldera, Indonesia, recorded by oxygen isotope zoning in quartz2017In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, article id 40624Article in journal (Refereed)
    Abstract [sv]

    Quartz is a common phase in high-silica igneous rocks and is resistant to post-eruptive alteration, thus offering a reliable record of magmatic processes in silicic magma systems. Here we employ the 75 ka Toba super-eruption as a case study to show that quartz can resolve late-stage temporal changes in magmatic δ18O values. Overall, Toba quartz crystals exhibit comparatively high δ18O values, up to 10.2‰, due to magma residence within, and assimilation of, local granite basement. However, some 40% of the analysed quartz crystals display a decrease in δ18O values in outermost growth zones compared to their cores, with values as low as 6.7‰ (maximum ∆core−rim = 1.8‰). These lower values are consistent with the limited zircon record available for Toba, and the crystallisation history of Toba quartz traces an influx of a low-δ18O component into the magma reservoir just prior to eruption. Here we argue that this late-stage low-δ18O component is derived from hydrothermally-altered roof material. Our study demonstrates that quartz isotope stratigraphy can resolve magmatic events that may remain undetected by whole-rock or zircon isotope studies, and that assimilation of altered roof material may represent a viable eruption trigger in large Toba-style magmatic systems.

  • 198. Buffington, Matthew L
    et al.
    Forshage, Mattias
    Swedish Museum of Natural History, Department of Zoology.
    Redescription of Ganaspis brasiliensis (Ihering, 1905), new combiantion, (Hymenoptera: Figitidae) a natural enemy of the invasive Drosophila suzukii (Matsumura, 1931) (Diptera: Drosophilidae)2016In: Proceedings of the Entomological Society of Washington, ISSN 0013-8797, Vol. 118, no 1, p. 1-13Article in journal (Refereed)
    Abstract [en]

    The new combination of Ganaspis brasiliensis (Ihering, 1905) is proposed, and the species is redescribed from historical specimens taken in the Neotropical Region as well as more recent specimens reared from Drosophila suzukii Matsumura, 1931 in South Korea. Drosophila suzukii, otherwise known as the spotted-wing Drosophila, is a major pest of soft fruits the world over, and the search for effective natural enemies of this fly are ongoing. Though not parasitoids of D. suzukii, we also propose the following new combinations: Dieucoila brasiliensis (Kieffer, 1909), new combination, and Dieucoila brasiliana (Weld, 1952), new combination. After summarizing all known species of Eucoilinae with the specific epithet ‘brasiliensis’, we encourage future researchers to avoid this name in order prevent nomenclatural confusion.

  • 199. Buffington, Matthew L
    et al.
    Forshage, Mattias
    Swedish Museum of Natural History, Department of Zoology.
    The description of Garudella Buffington and Forshage, new genus (Hymenoptera: Figitidae: Eucoilinae)2014In: Proceedings of the Entomological Society of Washington, ISSN 0013-8797, Vol. 116, no 3, p. 225-242Article in journal (Refereed)
    Abstract [en]

    Garudella, a remarkable new genus of eucoiline wasp is described from Thailand, Laos, and the Republic of Congo. Four new species of Garudella are described as well: G. acothonaspis, G. afrotropica, G. algo, and G. alicae. Several autapomorphies distinguish this genus from other eucoiline genera: a distinctly protracted and broadened pronotal plate; a massive, posteriorly protruding prop- odeum; reduced posterior rim of metapleuron; reduced scutellar foveae and lack of lateral bar “windows”; and a generally reduced scutellar plate. In addition, the posterior of the head has a distinctly curved occipital impression, resulting in the cuticle surrounding the foramen magnum to be extruded into a neck-like process. The biology of Garudella is unknown, but based on phylogenetic inference from morphology, the presumed host could be a cyclorrhaphous Diptera in a saprophagous environment.

  • 200. Buffington, Matthew L
    et al.
    Gallardo, Fabiana E
    Reche, Vanina
    Forshage, Mattias
    Swedish Museum of Natural History, Department of Zoology.
    A Revision of Zaeucoila Ashmead (Hymenoptera, Figitidae), Parasitoids of Agromyzidae (Diptera): New Species, Identity, Distribution, and Hosts2017In: Proceedings of the Entomological Society of Washington, ISSN 0013-8797, Vol. 119, no 3, p. 317-397Article in journal (Refereed)
    Abstract [en]

    The eucoiline genus Zaeucoila Ashmead is revised. Following a re- evaluation combining previously published phylogenetic data and new specimens, Agrostocynips D ́ıaz is synonymized with Zaeucoila. All species included in Zaeucoila are systematically treated, and now amounts to twelve, seven of which are described as new here: Zaeucoila bitiburculata new species, Z. fidalgoii new species, Z. infuscata new species, Z. johnsonii new species, Z. lignys new species, Z. normae new species, Z. patera new species. The following new combinations are proposed and species redescribed: Zaeucoila grenadensis (Ashmead), new combination; Z. robusta (Ashmead), new combination; Z. flavipes (Ashmead), new combination. Agrostocynips diastrophi (Ashmead), Agrostocynips clavatus D ́ıaz, and Agrostocynips enneatoma (D ́ıaz) are new synonyms of Zaeucoila robusta. Zaeucoila incompleta (Kieffer), Z. triangu- lifera Kieffer, and Z. unicarinata Ashmead are redescribed. Zaeucoila is an unusual genus of Zaeucoilini in its wide distribution area: it can be found from southern Argentina well into the eastern United States and southern Canada; no other zaeucoiline genus shows such a pattern. Host records and geographic data for Zaeucoila are brought up to date, as well as a key to species. Zeucoila are primary parasitoids of Agromyzidae, including Liriomyza trifolii and other species that are notable economic pests of agriculture. Tropideucoila fulvonotata (Kieffer) is transferred to Marthiella (new combination).

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