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  • 301.
    Deprá, Gabriel C.
    et al.
    Universidade Estadual de Maringá.
    Kullander, Sven O.
    Swedish Museum of Natural History, Department of Zoology.
    Pavanelli, Carla S,
    Universidade Estadual de Maringá.
    da Graça, Wefterson J.
    Universidade Estadual de Maringá.
    A new colorful species of Geophagus (Teleostei: Cichlidae), endemic to the rio Aripuanã in the Amazon basin of Brazil2014In: Neotropical Ichthyology, ISSN 1679-6225, E-ISSN 1982-0224, Vol. 12, no 4, p. 737-746Article in journal (Refereed)
    Abstract [en]

    Geophagus mirabilis, new species, is endemic to the rio Aripuanã drainage upstream from Dardanelos/Andorinhas falls.The new species is distinguished from all other species of the genus by the presence of one to five large black spots arrangedlongitudinally along the middle of the flank, in addition to the black midlateral spot that is characteristic of species in thegenus and by a pattern of iridescent spots and lines on the head in living specimens. It is further distinguished from allcongeneric species, except G. camopiensis and G. crocatus, by the presence of seven (vs. eight or more) scale rows in thecircumpeduncular series below the lateral line (7 in G. crocatus; 7-9 in G. camopiensis). Including the new species, five cichlids and 11 fish species in total are known only from the upper rio Aripuanã, and 15 fish species in total are known only from the rio Aripuanã drainage

  • 302. Devaere, Lea
    et al.
    Skovsted, Christian
    Swedish Museum of Natural History, Department of Paleobiology.
    New early Cambrian sclerites of Lapworthella schodakensis from NE Greenland: advancements in knowledge of lapworthellid taxonomy, sclerite growth and scleritome organization2017In: Geological Magazine, ISSN 0016-7568, E-ISSN 1469-5081, Vol. 154, no 5, p. 1061-1072Article in journal (Refereed)
    Abstract [en]

    The Cambrian Stage 4 upper Bastion Formation of Albert Heim Bjerge and CH Ostenfeld Nunatak, NE Greenland, yielded 34 excellently preserved sclerites of Lapworthella schodackensis among other small shelly fossils. Lapworthellids have been interpreted as members of the camenellans,a basal tommotiid group. Little is known about this group although the morphological andultrastructural features of their sclerites allow a potential reconstruction of a lophophorate body plan.The exquisite material from Greenland provides significant new data for the revision of the species taxonomy, but also for the comprehension of the scleritome structure of lapworthellids and the modeof formation of their sclerites. Two morphotypes of L. schodackensis sclerites are identified: one with asimple apex, occurring in sinistral and dextral forms; and one bilaterally symmetrical sclerite with twoapices. All bear a similar ornamentation constructed of repeated growth sets consisting of a reticulate inter-rib groove with tubercles, a densely denticulate rib and a striated sub-rib area. The new data onthe ornamentation and observations of the laminar shell microstructure of L. schodackensis enable us to improve the reconstruction of growth in lapworthellids. Finally, the morphological features of the two types of sclerites provide new information for the reconstruction of the bilaterally symmetrical multi-component lapworthellid scleritome with evidence of the fusion of adjacent sclerites duringearly ontogeny.

  • 303. Dias, Arildo S.
    et al.
    Santos, Karin
    Swedish Museum of Natural History, Department of Botany.
    Maës dos Santos, Flavio Antonio
    Martins, Fernando R.
    How liana loads alter tree allometry intropical forests2016In: Plant Ecology, ISSN 1385-0237, E-ISSN 1573-5052Article in journal (Refereed)
    Abstract [en]

    Intense competition with lianas (woodclimbers) can limit tree growth, reproduction, andsurvival. However, the negative effects of liana loadson tree allometry have not yet been addressed. Weinvestigated the hypothesis that liana loading on treecrown alters tree’s allometry, expressed throughslenderness (height–diameter ratio). The relationshipbetween trunk slenderness and percentage of treecrown covered by lianas was investigated for 12 treespecies from 10 fragments of the SemideciduousSeasonal Forest in Southeastern Brazil. We also testedwhether the relationship between slenderness andwood density differ between trees without lianas andtrees heavily infested. Liana loads significantly alteredtree allometry by decreasing slenderness, even whenlianas covered less than 25% of tree crown. Heavywoodspecies decreased their trunk slenderness in agreater ratio than light-wood species. Our findingsindicate that liana infestation shifts tree allometry, andthese effects are stronger on heavy-wood tree species.

  • 304. Dickinson, Edward C
    et al.
    Ericson, Per G P
    Swedish Museum of Natural History, Research Division.
    Systematic notes on Asian birds 32: The type locality of Hirundo daurica Laxmann, 17692002In: Zoologische Verhandelingen Leiden, ISSN 0024-1652, Vol. 340, p. 205-206Article in journal (Refereed)
    Abstract [en]

    The restricted type locality suggested by Brooke (1974) for Hirundo daurica Laxmann, 1769 was apparently made without a translation of the original Swedish description. With this in hand we find it necessary to correct that restriction and move the type locality some 2500 km west.

  • 305. Dickinson, Edward C.
    et al.
    Schodde, Richard
    Australian Biological Resources Study.
    Kullander, Sven
    Swedish Museum of Natural History, Department of Zoology.
    Chrochet, Pierre André
    Centre d'Ecologie Fonctionnelle et Evolutive.
    Elliott, Andy
    Lynx Edicions.
    Kirwan, Guy M
    Field Museum of Natural History.
    Correcting the "correct" name for the Asian Brown Flycatcher (Aves: Passeriformes, Muscicapidae, Muscicapa)2014In: Zootaxa, ISSN 1175-5326, E-ISSN 1175-5334, Vol. 3869, no 3, p. 343-347Article in journal (Refereed)
    Abstract [en]

    Muscicapa dauurica Pallas, 1811 is shown to be an available name and the oldest available name for the Asian Brown Flycatcher

  • 306. Dickison, William C.
    et al.
    Lundberg, Johannes
    Swedish Museum of Natural History, Department of Botany.
    Paracryphiaceae2016In: Flowering Plants. Eudicots: Aquifoliales, Boraginales, Bruniales, Dipsacales, Escalloniales, Garryales, Paracryphiales, Solanales (except Convolvulaceae), Icacinaceae, Metteniusaceae, Vahliaceae / [ed] Kadereit, Joachim W., Bittrich, Volker, Springer, 2016, p. 281-285Chapter in book (Refereed)
    Abstract [en]

    Shrubs to medium-sized trees, some vines. Leaves alternate to almost verticillate (Paracryphia), simple, margins finely serrate or sometimes entire; stipules absent; dense pubescence on young leaves, absent on mature foliage. Flowers in axillary or terminal racemes or compound spikes, bisexual or unisexual (plants andromonoecious); perianth differentiated into 4–5 sepals and 4–5 white, free, deciduous petals (Quintinia), or with undifferentiated perianth of 4 caducous, decussate, concave, free, imbricate segments (Paracryphia); stamens 4–5 (Quintinia) or ca. 8 (Paracryphia) in a single whorl; anthers basifixed, tetrasporangiate, with longitudinal dehiscence; ovary superior (Paracryphia) or inferior (Quintinia); 8–15- (Paracryphia) or 3–5-locular (Quintinia), ovules 4 per locule (Paracryphia) or numerous; style elongated with 3–5-lobed stigma (Quintinia), or absent (Paracryphia). Fruit capsular, septicidal; seeds small, winged in Paracryphia and mostQuintina, copiously endospermic.

  • 307. Diederich, P.
    et al.
    Millanes, A.M.
    Wedin, Mats
    Swedish Museum of Natural History, Department of Botany.
    Tremella umbilicariae (Tremellomycetes, Basidiomycota), a new lichenicolous species on Umbilicaria from Peru2015In: Bulletin de la Société des Naturalistes Luxembourgeois, Vol. 115, p. 167-172Article in journal (Refereed)
  • 308. Diederich, P.
    et al.
    Millanes, A.M.
    Wedin, Mats
    Swedish Museum of Natural History, Department of Botany.
    Tremella umbilicariae (Tremellomycetes, Basidiomycota), a new lichenicolous species on Umbilicaria from Peru2014In: Bulletin de la Société des Naturalistes Luxembourgeois, Vol. 115, p. 167-172Article in journal (Refereed)
  • 309. DiMaggio, Erin N.
    et al.
    Campisano, Christopher J.
    Rowan, John
    Dupont-Nivet, Guillaume
    Deino, Alan L.
    Bibi, Faysal
    Lewis, Margaret
    Souron, Antoine
    Werdelin, Lars
    Swedish Museum of Natural History, Department of Paleobiology.
    Reed, Kaye E.
    Arrowsmith, J. Ramon
    Late Pliocene Fossiliferous Sedimentary Record and the Environmental Context of early Homo from Afar, Ethiopia2015In: Science, Vol. 347, p. 1355-1359Article in journal (Refereed)
  • 310. Dimitrieva, L
    et al.
    Härkönen, Tero
    Swedish Museum of Natural History, Department of Environmental research and monitoring.
    Baimukanov, M
    Bignert, Anders
    Swedish Museum of Natural History, Department of Environmental research and monitoring.
    Jüssi, I
    Jüssi, M
    Kasimbekov, Y
    Verevkin, M
    Vysotskiy, V
    Wilson, S
    Goodman, SJ
    Inter-year variation in pup production of Caspian seals (Pusa caspica) 2005-2012 determined from aerial surveys2015In: Endangered species research, ISSN 1863-5407Article in journal (Refereed)
  • 311.
    D'Ippolito, Veronica
    et al.
    Sapienza Università di Roma.
    Andreozzi, Giovanni B.
    Sapienza Università di Roma.
    Bosi, Ferdinando
    Swedish Museum of Natural History, Department of Geology.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Blue spinel crystals in the MgAl2O4-CoAl2O4 series: I. Flux growth and chemical characterisation2012In: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 97, p. 1828-1833Article in journal (Refereed)
  • 312.
    D'Ippolito, Veronica
    et al.
    Sapienza Università di Roma.
    Andreozzi, Giovanni B.
    Sapienza Università di Roma.
    Bosi, Ferdinando
    Swedish Museum of Natural History, Department of Geology.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Mantovani, L.
    Università di Parma.
    Bersani, D.
    Università di Parma.
    Fregola, Rosa Anna
    Università di Bari.
    Crystallographic and spectroscopic characterisation of a natural Zn-rich spinel approaching the endmember gahnite (ZnAl2O4) composition2013In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 77, p. 2941-2953Article in journal (Refereed)
  • 313.
    D'Ippolito, Veronica
    et al.
    Sapienza University, Rome, Italy.
    Andreozzi, Giovanni
    Sapienza University, Rome, Italy.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Hametner, Kathrin
    ETH, Zürich, Switzerland.
    Günther, Detlef
    ETH, Zürich, Swizerland.
    Color mechanisms in spinel: cobalt and iron interplay for the blue color2015In: Physics and chemistry of minerals, ISSN 0342-1791, E-ISSN 1432-2021, Vol. 42, no 6, p. 431-439Article in journal (Refereed)
    Abstract [en]

    Six natural, blue colored spinel crystals were studied chemically by electron microprobe and laser ablation inductively coupled plasma mass spectrometry (LAICP-MS) techniques and optically by UV–VIS–NIR–MIR spectroscopy in the range 30,000–2,000 cm1  to investigate the causes of their blue color hues. The positions of the absorption bands vary only marginally with the principal composition of the samples (gahnite vs. spinel s.s .). Although blue colors in spinels are frequently the result of various electronic processes in Fe cations, we demonstrate by comparison with synthetic Co-bearing samplesthat Co acts as an important chromophore also in natural spinels. Already at concentration levels of a few ppm (e.g.,>10 ppm), cobalt gives rise to absorption bands at ~18,000, 17,000 and 16,000 cm1  that result in distinct blue coloration. In spinels with insignificant Co contents, different shades of paler blue (from purplish to greenish blue) colors are caused by electronic transitions in TFe2+, MFe2+, MFe3and Fe2+–Fe3 cation pairs.

  • 314. Divakar, Pradeep K.
    et al.
    Crespo, Ana
    Wedin, Mats
    Swedish Museum of Natural History, Department of Botany.
    Ohlson, Jan I
    Swedish Museum of Natural History, Department of Bioinformatics and Genetics.
    Evolution of complex symbiotic relationships in a morphologically derived family of lichen-forming fungi2015In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 208, p. 1217-1226Article in journal (Refereed)
  • 315. Djursvoll, Per
    et al.
    Golovatch, S. I.
    Johanson, Kjell Arne
    Swedish Museum of Natural History, Department of Zoology. Swedish Museum of Natural History.
    Meidell, Bjarne
    Phylogenetic relationships within Polydesmus sensu lato (Diplopoda: Polydesmida)2001In: Fragmenta Faunistica, Vol. 43, p. 37-59Article in journal (Refereed)
  • 316. Doan, Karolina
    et al.
    Mackiewicz, Pawel
    Sandoval-Castellanos, Edson
    Stefaniak, Krzysztof
    Ridush, Bogdan
    Dalén, Love
    Swedish Museum of Natural History, Department of Bioinformatics and Genetics.
    Weglenski, Piotr
    Stankovic, Ana
    The history of Crimean red deer population and Cervus phylogeography in Eurasia2018In: Zoological Journal of the Linnean Society, ISSN 0024-4082, E-ISSN 1096-3642, Vol. 183, no 1, p. 208-225Article in journal (Refereed)
  • 317.
    Doguzhaeva, Larisa
    Swedish Museum of Natural History, Department of Paleobiology.
    Functional significance of parabolae, interpreted on the basis of shell morphology, ultrastructure and chemical analyses of the Callovian ammonite Indosphinctes (Ammonoidea: Perisphinctidae), Central Russia2012In: Revue de Paléobiologie, Genève, ISSN ISSN 0253-6730, Vol. 11, p. 89-101Article in journal (Refereed)
    Abstract [en]

    The parabola-bearing shells of the Callovian ammonite Indosphinctes (Elatmites) submutatus Nikitin from Ryazan Region, Central Russia, are examined using morphological, ultrastructural and chemical approaches to clarify the functional significance of the parabola.The parabolae are missing in the embryonic shell that is comparatively large (about 1.5 mm in diameter) and has a prismatic shell wall, with the exception of the nacreous primary varix. There are no parabolae at the early post-hatching stage at which the shell wall consists of the outer prismatic, middle nacreous and inner prismatic layers. The parabolae are observed in small and medium-sized shells (about 15-30 mm in diameter) in which the bulk of the lateral and ventral portions of the shell wall are formed by the nacreous layer, and the outer prismatic layer seems to be missing. The thin dorsal wall lacks the nacreous layer, and the adjacent whorls are connected via a structureless layer showing a nano-granular ultrastructure. Beyond the contact of the whorls, the broken rolled ends of this layer are only preserved at the corners between the neighboring whorls. This perishable layer contains N (an indicator of organic ingredient preserved), C, O, Mg, Ca, Fe, Zn, and Sr. The same elements are detected in the structureless shell material from repaired injuries of the shell wall. There are about seven parabolae in a whorl. The parabolae are commonly exhibited on the exposed dorsal wall when the next whorl is broken. The parabolae are also observed on the outer shell surface not yet covered with the dorsal wall of the next whorl. The body chamber is about 330° in spiral length. The paired adorally ‘opened’ parabolic ‘notches’ are expressed either as small knobs on internal moulds, as nodes on the dorsal wall, or as a contour reinforced with minor relief on outer surface of the body chamber. A parabolic node represents a lens-like inclusion into the nacreous layer of the shell wall and is composed of flattened, loosely packed spherulites and nacreous micro-chips. Based on these observations it is suggested that (1) the shell of I. (E.) submutatus, excepting earlyontogenetic stages, was coated with an organic-rich layer, possibly secreted from the outside like the outer plate in the shell wall of extant Spirula; (2) the parabolae served as attachment structures related to the mantle attachment inside and outside the body chamber.

  • 318.
    Doguzhaeva, Larisa
    Swedish Museum of Natural History, Department of Paleobiology.
    The body chamber length variations and muscle and mantle attachments in ammonoids.2015In: Ammonoid paleobiology: From Anatomy to Ecology / [ed] C. Klug et al., Springer Science+Business Media Dordrecht: Springer, 2015, 2nd, p. 545-584Chapter in book (Refereed)
  • 319.
    Doguzhaeva, Larisa
    Swedish Museum of Natural History, Department of Paleobiology.
    THE ORIGINAL COMPOSITION OF THE PROOSTRACUM OF AN EARLY SINEMURIAN BELEMNITE FROM BELGIUM DEDUCED FROM MODE OF FOSSILIZATION AND ULTRASTRUCTURE2012In: Palaeontology, ISSN 0031-0239, E-ISSN 1475-4983, Vol. 55, no 2, p. 249-260, article id doi: 10.1111/j.1475-4983.2012.01136.xArticle in journal (Refereed)
    Abstract [en]

    The pro-ostracum of the early Sinemurian belemnite Nannobelus from the Belgian Province of Luxembourg is preserved as a thin, irregularly mineralized (phosphatized and pyritized), finely laminated structure, which is situated dorsally between the calcified rostrum and phragmocone. It has a median field with a criss-cross pattern of bluntly pointed, curved growth lines and fine longitudinal ridges, as well as two lateral fields characterized by a fine ornament of closely spaced, longitudinal striae, each lateral field showing a narrow anterior belt-like portion, the width of which equals about one-third of that of the median field. Their posterior portion is remarkably asymmetrical, because its free margin (which does not about the median field) curves ventrally and the interspace between striae gradually increases here. The striation of the lateral field is formed by the longitudinally exposed narrow portions of succeeding, overlapping sublayers of the pro-ostracum. Additionally, an internal sublayer with a silicified, honeycomb-like structure is demonstrated in the pro-ostracum. Based on microlamination that is comparable to that of the chitinous gladius inextant squids and on the irregular mineralization (unlike the rest of the shell), the pro-ostracum is considered to have been originally mainly organic, containing an intermediate cartilaginous sublayer with a typical honeycomb-like structure The cartilaginous sublayer supposedly provided protection of the pro-ostracum against fractures which might have resulted from regular contractions together with the muscular mantle during jet-propulsion. Ultrastructural and chemical data on Nannobelus favour the interpretation of the pro-ostracum as a novelty of the skeleton in coleoids rather than as a dorsal projection of the phragmocone wall.

  • 320.
    Doguzhaeva, Larisa
    Swedish Museum of Natural History, Department of Paleobiology.
    THE ORIGINAL COMPOSITION OF THE PROOSTRACUM OF AN EARLY SINEMURIAN BELEMNITE FROM BELGIUM DEDUCED FROM MODE OF FOSSILIZATION AND ULTRASTRUCTURE2012In: Palaeontology, ISSN 0031-0239, E-ISSN 1475-4983, Vol. 55, no 2, p. 249-260Article in journal (Refereed)
    Abstract [en]

    The pro-ostracum of the early Sinemurian belemnite Nannobelus from the Belgian Province of Luxembourg is preserved as a thin, irregularly mineralized (phosphatized and pyritized), finely laminated structure, which is situated dorsally between the calcified rostrum and phragmocone. It has a median field with a criss-cross pattern of bluntly pointed, curved growth lines and fine longitudinal ridges, as well as two lateral fields characterized by a fineornament of closely spaced, longitudinal striae, each lateral field showing a narrow anterior belt-like portion, the width of which equals about one-third of that of the median field. Their posterior portion is remarkably asymmetrical, because its free margin (which does not about the median field) curves ventrally and the interspace between striae gradually increases here. The striation of the lateral field is formed by the longitudinally exposed narrow portions of succeeding, overlapping sublayers of the pro-ostracum. Additionally, an internal sublayer with a silicified, honeycomb-like structure is demonstrated in the pro-ostracum. Based on microlamination that is comparable to that of the chitinous gladius in extant squids and on the irregular mineralization (unlike the rest of the shell), the pro-ostracum is considered to have been originally mainly organic, containing an intermediate cartilaginous sublayer with a typical honeycomb-like structure. The cartilaginous sublayer supposedly provided protection of the pro-ostracum against fractures which might have resulted from regular contractions together with the muscular mantle during jet-propulsion. Ultrastructural and chemical data on Nannobelus favour the interpretation of the pro-ostracum as a novelty of the skeleton in coleoids rather than as a dorsal projection of the phragmocone wall.

  • 321.
    Doguzhaeva, Larisa A.
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Weaver, Patricia G.
    North Carolina Museum of Natural Sciences.
    Ciampaglio, Charles N.
    Wright State University.
    A unique late Eocene coleoid cephalopod Mississaepia from Mississippi, USA: New data on cuttlebone structure, and their phylogenetic implications.2014In: Acta Palaeontologica Polonica, ISSN 0567-7920, E-ISSN 1732-2421, Vol. 59, no 1, p. 147-162Article in journal (Refereed)
    Abstract [en]

    A new family, Mississaepiidae, from the Sepia–Spirula branch of decabrachian coleoids (Cephalopoda), is erected on the basis of the following, recently revealed, morphological, ultrastructural and chemical traits of the cuttlebone in the late Eocene Mississaepia, formerly referred to Belosaepiidae: (i) septa are semi−transparent, largely chitinous (as opposed to all other recorded cephalopods having non−transparent aragonitic septa); (ii) septa have a thin lamello−fibrillar nacreous covering (Sepia lacks nacre altogether, Spirula has fully lamello−fibrillar nacreous septa, ectochochleate cephalopods have columnar nacre in septa); (iii) a siphonal tube is present in early ontogeny (similar to siphonal tube development of the Danian Ceratisepia, and as opposed to complete lack of siphonal tube in Sepiaand siphonal tube development through its entire ontogeny in Spirula); (iv) the lamello−fibrillar nacreous ultrastructure of septal necks (similar to septal necks in Spirula); (v) a sub−hemispherical protoconch (as opposed to the spherical protoconchs of the Danian Ceratisepia and Recent Spirula); (vi) conotheca has ventro−lateral extension in early ontogenetic stages (as opposed to Sepia that has no ventro−lateral extention of the conotheca and to Spirula that retains fully−developed phragmocone throughout its entire ontogeny). Chitinous composition of septa in Mississaepia is deduced from (i) their visual similarity to the chitinous semi−transparent flange of Sepia, (ii) angular and rounded outlines and straight compressive failures of the partial septa and mural parts of septa similar to mechanically−damaged dry rigid chitinous flange of Sepia or a gladius of squid, and (iii) organics consistent with −chitin preserved in the shell. The family Mississaepiidae may represent a unknown lineage of the Sepia–Spirulabranch of coleoids, a conotheca lacking a nacreous layer being a common trait of the shell of this branch. However, Mississaepiidae is placed with reservation in Sepiida because of similarities between their gross shell morphology (a cuttlebone type of shell) and inorganic−organic composition. In Mississaepia, as in Sepia, the shell contains up to 6% of nitrogen by weight; phosphatised sheets within the dorsal shield may have been originally organic, like similar structures in Sepia; accumulations of pyrite in peripheral zones of aragonitic spherulites and in−between the spherulites of the dorsal shield may also indicate additional locations of organics in the shell of living animal.

  • 322.
    Doguzhaeva, Larisa A.
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Weis, Robert
    Musée national d’histoire naturelle, Luxembourg.
    Delsate, Dominique
    Musée national d’histoire naturelle, Luxembourg.
    Mariotti, Nino
    Università ‘La Sapienza’, Roma, Italy.
    Embryonic shell structure of Early–Middle Jurassic belemnites, and its significance for belemnite expansion and diversification in the Jurassic.2014In: Lethaia: an international journal of palaeontology and stratigraphy, ISSN 0024-1164, E-ISSN 1502-3931, Vol. 47, no 1, p. 49-65Article in journal (Refereed)
    Abstract [en]

    Early Jurassic belemnites are of particular interest to the study of the evolution of skeletal morphology in Lower Carboniferous to the uppermost Cretaceous belemnoids, because they signal the beginning of a global Jurassic–Cretaceous expansion and diversification of belemnitids. We investigated potentially relevant, to this evolutionary pattern, shell features of Sinemurian–Bajocian Nannobelus, Parapassaloteuthis, Holcobelus and Pachybelemnopsis from the Paris Basin. Our analysis of morphological, ultrastructural and chemical traits of the earliest ontogenetic stages of the shell suggests that modified embryonic shell structure of Early–Middle Jurassic belemnites was a factor in their expansion and colonization of the pelagic zone and resulted in remarkable diversification of belemnites. Innovative traits of the embryonic shell of Sinemurian– Bajocian belemnites include: (1) an inorganic–organic primordial rostrum encapsulating the protoconch and the phragmocone, its non-biomineralized component, possibly chitin, is herein detected for the first time; (2) an organic rich closing membrane which was under formation. It was yet perforated and possessed a foramen; and (3) an organic rich pro-ostracum earlier documented in an embryonic shell of Pliensbachian Passaloteuthis. The inorganic–organic primordial rostrum tightly coating the protoconch and phragmocone supposedly enhanced protection, without increase in shell weight, of the Early Jurassic belemnites against explosion in deepwater environment. This may have increased the depth and temperature ranges of hatching eggs, accelerated the adaptation of hatchlings to a nektonic mode of life and promoted increasing diversity of belemnoids. This study supports the hypothesis that belemnite hatchlings were ‘a miniature of the adults’.

  • 323. Doguzhaeva, Larisa
    et al.
    Bengtson, Stefan
    Swedish Museum of Natural History, Department of Paleobiology.
    The capsule – a newly discovered organic shell structure in the Late Cretaceous belemnite Gonioteuthis from north-west Germany.2011In: Palaeontology, ISSN 0031-0239, E-ISSN 1475-4983, Palaeontology, Vol. 54, no 2, p. 397-415Article in journal (Refereed)
    Abstract [en]

    An unusual, bilaterally symmetrical black structure that embraces the protoconch and the phragmocone and is overlain by a rostrum has been studied in the Santonian– early Campanian (Late Cretaceous) belemnite genus Gonioteuthis from Braunschweig, north-west Germany. The structure is here named the capsule. Energy dispersed spectrometry analyses of the capsule show a co-occurrence of sulphur with zinc, barium, iron, lead and titanium, suggesting their chemical association. The capsule was originally made of organic material that was diagenetically transformed into sulphur-containing matter. The material of the capsule differs from the chitin of the connecting rings in the same specimens. The capsule has a complex morphology: (1) ventral and dorsal wing-like projections that are repeated in a breviconic shape of the alveolus, (2) an aperture with lateral lobes and ventral and dorsal sinuses copied by growth lines and (3) a ventral ridge that fits with the position of the fissure in the rostrum. The alveolus in the most anterior part of the rostrum is crater-like. It is lined with thin, pyritized, laminated material, which appears to be the outermost portion of the capsule attached to the inner surface of the rostrum. A flare along the periphery of the alveolus marks a region where the rostrum was not yet formed, suggesting that the capsule extended beyond the rostrum. Modification of the skeleton in Gonioteuthis comprises a set of supposedly interrelated changes, such as innovation of the organic capsule, partial elimination of the calcareous rostrum and a diminishing of the pro-ostracum, resulting in the appearance of a new type of pro-ostracum that became narrower and shorter and lost the spatula-like shape and gently curved growth lines of a median field that are typical for the majority of Jurassic and Cretaceous belemnites. The partial replacement of a calcareous rostrum with an organic capsule in belemnitellids may have been an adaptive reaction to an unfavourable environmental condition, perhaps related to difficulties in calcium carbonate secretion during the Late Cretaceous that forced animals to reduce carbonate production and to secret an organic capsule around the protoconch and the phragmocone.

  • 324.
    Doguzhaeva, Larisa
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Bengtson, Stefan
    Swedish Museum of Natural History, Department of Paleobiology.
    THE CAPSULE: AN ORGANIC SKELETAL STRUCTURE IN THE LATE CRETACEOUS BELEMNITE GONIOTEUTHIS FROM NORTH-WEST GERMANY2011In: Palaeontology, ISSN 0031-0239, E-ISSN 1475-4983Article in journal (Refereed)
    Abstract [en]

    An unusual, bilaterally symmetrical black structure that embraces the protoconch and the phragmocone and is overlain by a rostrum has been studied in the Santonian–early Campanian (Late Cretaceous) belemnite genus Gonioteuthis from Braunschweig, north-west Germany. The structure is here named the capsule. Energy dispersed spectrometry analyses of the capsule show a co-occurrence of sulphur with zinc, barium, iron, lead and titanium, suggesting their chemical association. The capsule was originally made of organic material that was diagenetically transformed into sulphur-containing matter. The material of the capsule differs from the chitin of the connecting rings in the same specimens. The capsule has a complex morphology: (1) ventral and dorsal wing-like projections that are repeated in a breviconic shape of the alveolus, (2) an aperture with lateral lobes and ventral and dorsal sinuses copied by growth lines and (3) a ventral ridge that fits with the position of the fissure in the rostrum. The alveolus in the most anterior part of the rostrum is crater-like. It is lined with thin, pyritized, laminated material, which appears to be the outermost portion of the capsule attached to the inner surface of the rostrum. A flare along the periphery of the alveolus marks a region where the rostrum was not yet formed, suggesting that thecapsule extended beyond the rostrum. Modification of the skeleton in Gonioteuthis comprises a set of supposedly interrelated changes, such as innovation of the organic capsule, partial elimination of the calcareous rostrum and a diminishing of the pro-ostracum, resulting in the appearance of a new type of pro-ostracum that became narrower and shorter and lost the spatula-like shape and gently curved growtlines of a median field that are typical for the majority of Jurassic and Cretaceous belemnites. The partial replacement of a calcareous rostrum with an organic capsule in belemnitellids may have been an adaptive reaction to an unfavourable environmental condition, perhaps related to difficulties in calcium carbonate secretion during the Late Cretaceous that forced animals to reduce carbonate production and to secret an organic capsule around the protoconch and the phragmocone.

  • 325.
    Doguzhaeva, Larisa
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Bengtson, Stefan
    Swedish Museum of Natural History, Department of Paleobiology.
    Mutvei, Harry
    Swedish Museum of Natural History, Department of Paleobiology.
    Structural and morphological indicators of mode of life in the Aptian lytoceratid ammonoid Eogaudryceras2010In: Cephalopods - Present and Past / [ed] Tanabe, K., Shigeta, Y., Sasaki, T. & Hirano, H., Tokyo, Japan: Tokai University Press , 2010, First, p. 123-130Chapter in book (Refereed)
    Abstract [en]

    The shell wall ultrastructure, collars, wrinkle layer, siphuncle morphology, and the ultrastructure of the connecting rings are described in the Aptian (Early Cretaceous) lytoceratid Eogaudryceras Spath from Adygeya, north-western Caucasus, Russia. The collars are pronounced and number 4-5 per shell whorl. They enlarged the shell surface and increased the buoyancy and mechanical shell strength. The siphuncular tube consists of calcareous prochoanitic septal necks and cuffs that became proportionally longer during the ontogeny, and comparatively short, organic (possibly glycoprotein) connecting rings that are phosphatized and consist of aggregates of small globular particles. There is some evidence of a porous structure, which may have provided a higher permeability of the connecting rings and increased the gas/liquid exchange between the siphuncle and shell chambers for vertical migrations. The morphological and structural shell characteristics indicate that the shell design was adapted for pelagic, probably deep-water habitat, and vertical, possibly diurnal, migrations.

  • 326. DOGUZHAEVA, Larisa
    et al.
    BENGTSON, Stefan
    REGUERO, Marcelo
    Mörs, Thomas
    Swedish Museum of Natural History, Department of Paleobiology.
    An Eocene orthocone from Antarctica shows convergent evolution of internally shelled cephalopods2017In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 12, no 3, article id e0172169Article in journal (Refereed)
    Abstract [en]

    Background

    The Subclass Coleoidea (Class Cephalopoda) accommodates the diverse present-day internally shelled cephalopod mollusks (Spirula, Sepia and octopuses, squids, Vampyroteuthis) and also extinct internally shelled cephalopods. Recent Spirula represents a unique coleoid retaining shell structures, a narrow marginal siphuncle and globular protoconch that signify the ancestry of the subclass Coleoidea from the Paleozoic subclass Bactritoidea. This hypothesis has been recently supported by newly recorded diverse bactritoid-like coleoids from the Carboniferous of the USA, but prior to this study no fossil cephalopod indicative of an endochochleate branch with an origin independent from subclass Bactritoidea has been reported.

    Methodology/Principal findings

    Two orthoconic conchs were recovered from the Early Eocene of Seymour Island at the tip of the Antarctic Peninsula, Antarctica. They have loosely mineralized organic-rich chitin-compatible microlaminated shell walls and broadly expanded central siphuncles. The morphological, ultrustructural and chemical data were determined and characterized through comparisons with extant and extinct taxa using Scanning Electron Microscopy/Energy Dispersive Spectrometry (SEM/EDS).

    Conclusions/Significance

    Our study presents the first evidence for an evolutionary lineage of internally shelled cephalopods with independent origin from Bactritoidea/Coleoidea, indicating convergent evolution with the subclass Coleoidea. A new subclass Paracoleoidea Doguzhaeva n. subcl. is established for accommodation of orthoconic cephalopods with the internal shell associated with a broadly expanded central siphuncle. Antarcticerida Doguzhaeva n. ord., Antarcticeratidae Doguzhaeva n. fam., Antarcticeras nordenskjoeldi Doguzhaeva n. gen., n. sp. are described within the subclass Paracoleoidea. The analysis of organic-rich shell preservation of A. nordenskjoeldi by use of SEM/EDS techniques revealed fossilization of hyposeptal cameral soft tissues. This suggests that a depositional environment favoring soft-tissue preservation was the factor enabling conservation of the weakly mineralized shell of A. nordenskjoeldi.

  • 327.
    Doguzhaeva, Larisa
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Dunca, Elena
    Swedish Museum of Natural History, Department of Paleobiology.
    Siphonal zone structure in the cuttlebone of Sepia officinalis2015In: Swiss Journal of Palaeontology, article id 10.1007/s13358-015-0085-yArticle in journal (Refereed)
    Abstract [en]

    The evolutionary process through which the siphonal zone of the cuttlebone of Sepia replaced the tubular siphuncle seen in other shelled cephalopods is poorly understood. Recently, porous connecting stripes, interpreted as homologous to connecting rings of tubular siphuncles, were revealed in Sepia (Acanthosepion) cf. savignyi (Geobios, 45:13–17, 2012). New data on the siphonal zone structure are herein demonstrated through SEM testing of 16 beach-collected cuttlebones ofSepia officinalis from Vale do Lobo, southern Portugal. In examined cuttlebones, the organic connecting stripes are mineralized along their peripheries where they are attached to septa by inorganic–organic porous contacting ridges. The contacting ridges consist of globular crystalline units within an organic matrix; each globule is a stack of rounded alternating organic and mineralized microlaminas parallel to the septal surface; mineralized microlaminas contain carbonate microgranules. Porous connecting stripes together with the contacting ridges may serve as transport routes for the cameral liquid used in buoyancy regulation. The contacting ridges appear to reinforce contacts between the connecting stripes and septa, and may strengthen shell resistance to changing environments. Lamella–fibrillar nacre in septa is demonstrated in Sepia for the first time. Comparison of Sepia and Spirula reveals the common character of their phragmocones, the slit-like shape of the permeable zones between chambers and the siphuncle. Narrowing of the permeable zones may provide shell resistance to high hydrostatic pressure; however, the essentially dissimilar relative length of the permeable zones may results in different capabilities of two genera for buoyancy regulation. In Sepia, long narrow porous inorganic–organic permeable connecting stripes and contacting ridges may allow for rapid buoyancy regulation which would lead to environmental plasticity and higher species diversity.

  • 328.
    Doguzhaeva, Larisa
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Mapes, Royal
    North Carolina Museum of Natural Sciences.
    Arm hooks and structural features in the Early Permian Glochinomorpha Gordon 1971, indicative of its coleoid affiliation.2014In: Lethaia: an international journal of palaeontology and stratigraphy, ISSN 0024-1164, E-ISSN 1502-3931, article id DOI: 10.1111/let.12091Article in journal (Refereed)
    Abstract [en]

    Data on the re-examined-type specimens of the Early Permian Glochinomorpha stifeli Gordon 1971 (Coleoidea, Cephalopoda) gives new insight into the evolutionary origination of gladius-bearing coleoids in the Late Palaeozoic and suggests their parallel evolution with the belemnoids and phragmoteuthids. The iron-oxidized arm hooks are found in front of a gladius on an un-illustrated paratype (USNM 170614). Theyare dispersed in a maximum distance equal to 2.5 the gladius length from the incomplete anterior end of the rachis of the gladius. The hook height ranges from less than 1 mm to as much as 4 mm. They have a massive curved base, and a strongly curved shaft with a long thin distal part. The hooks confirm the cephalopod and the coleoid affiliation of G. stifeli that is widely rejected. The iron-oxidized gladii (preserved length is less than 20 mm) show micro-laminations and a fibrous ultrastructure; the fibre bundles are approximately 0.5 lm thick. Lack of calcium and the high content of nitrogen (up to 12% of total weight) confirm the originally non-biomineralized (apparently chitin) composition of the gladii suggested by their fibrous ultrastructure. These data lead to the conclusion that in the evolutionary history of gladius-bearing coleoids, the biomaterial (biochemical) development of the skeleton preceded its morphological transformation. This phenomenon resulted in a recombination of an advanced composition (being non-biomineralized) with archaic features (sensu morphological structure of the posterior part) in the gladius of G. stifeli. The data castdoubt on the hypothesized origination of a gladius from a phragmoteuthid pro-ostracum as well as the evolutionary origination of the gladius-bearing coleoids from pro-ostracum-bearing phragmoteuthids or belemnitids.

  • 329.
    Doguzhaeva, Larisa
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Mapes, Royal
    American Museum of Natural History, USA.
    Beak from the body chamber of the Early Carboniferous (Visean) shelled longiconic coleoid (Cephalopoda) from Arkansas, USA: -2017In: Lethaia: an international journal of palaeontology and stratigraphy, ISSN 0024-1164, E-ISSN 1502-3931Article in journal (Refereed)
    Abstract [en]

    Here we report the discovery of an Early Carboniferous (Late Visean) 3D cephalopod beak displaying significant similarity to the lower beak of Recent coleoids. It was uncovered in a fragmentarily preserved, longiconic shell from the Moorefield Formation in Arkansas, USA. This shell comprises a fractured 29-mm-long body chamber having a maximum diameter of ~14 mm and showing an indistinct pro-ostracum-like structure. The beak-bearing shell could easily have been mistaken for a bactritid or orthocerid if it were not for a coleoid-type, weakly mineralized, evidently organic-rich shell wall which shows a lamello-columnar ultrastructure of a bulk of shell wall thickness and plate ultrastructure of thin outer layer. The specimen is assigned to an as-yet unnamed shelled coleoid of a so far unknown high-level taxonomic group. A partially exposed, 4.0-mm-long portion of the beak is the lower beak in oblique view from its left side. It exhibits fractured anthracite-like black, apparently originally chitin material, helmet-like general shape, broad hood with narrow shallow median groove and small notch posteriorly, pronounced pointed, non-biomineralized upside belt rostrum, high shoulder and about a 90–100 degrees jaw angle. A broad hood and massive rostrum emphasize its similarity to the lower mandible of Recent Vampyroteuthis and signify that its unique, among living coleoids, structure has been existed for at least since Late Visean time (~333 my).

  • 330.
    Doguzhaeva, Larisa
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Mapes, Royal
    2Department of Geological Sciences, Ohio University, Athens, Ohio, USA.
    Mutvei, Harry
    Swedish Museum of Natural History, Department of Paleobiology.
    Evolutionary patterns of Carboniferous coleoid cephalopods based on their diversity and morphological plasticity2010In: Cephalopods - Present and Past / [ed] Tanabe, K., Shigeta, Y., Sasaki, T. & Hirano, H., Tokyo, Japan: Tokai University Press , 2010, First, p. 171-180Chapter in book (Refereed)
    Abstract [en]

    The morphological traits of the Carboniferous coleoids were analyzed to discover re-occurring combinations of different characteristic features during the early evolution of coleoid cephalopods. The early coleoid evolution in the Carboniferous is characterized by (1) a complex mosaic combination of the "old" and "new" morphological traits, (2) the parallel appearance and variations of new morphological features, and (3) relatively rapid changes in basic morphology. A mosaic combination is exemplified with Donovaniconus, which possesses a body chamber (bactritoid trait), a pro-ostracum-like structure (a novelty), and an ink sac (coleoid trait), or Mutveiconites, which combines a body chamber (bactritoid trait) and a rostrum (coleoid trait). A novelty or new feature can appear at any evolutionary stage, but "old" traits can continue to exist for a long period after the appearance of a novelty in another form. An example of this phenomenon is demonstrated by the evolutionary loss of the body chamber in the Lower Carboniferous (ca. 325 MY) taxon Hematites, which is the earliest recorded coleoid, and the retention of the body chamber in the Late Carboniferous (ca. 290 MY) taxa Shimanskya, Mutveiconites, Donovaniconus, and Saundersites. The parallel appearance of new morphological traits is illustrated by the appearance of the massive rostrum in the Early Carboniferous Hematites and the development of a cap-like small loosely calcified rostrum in the Late Carboniferous Mutveiconites.

  • 331.
    Doguzhaeva, Larisa
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Meléndez, Guillermo
    University of Zaragoza, Spain.
    The embryonic conch structure as a supposed imperative factor on the hatchling dispersal and geographical expansion of belemnites: an example of Callovian (Middle Jurassic) pachybelemnopseins from Aragόn (NE Spain): -2017In: Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, ISSN 0077-7749, Vol. 283, no 3, p. 317-334, article id 10.1127/njgpa/2017/0645Article in journal (Refereed)
    Abstract [en]

    Scanning electron microscopy, energy dispersive spectrometry and taphonomic analysis are applied for studying of about 250 shells of the pachybelemnopsein belemnites Hibolithes and Pachybelemnopsis. They are abundantly exposed on solid carbonate bedding surfaces of the middle-late Callovian deposits in the vicinity of the village Ricla, Iberian Range, Aragón, NE Spain. The evidences of their autochthonous burial are as follows: (i) high occurrence of very small, small, and medium-size specimens; the maximum diameter of the rostrum in each category is 2-3 mm, 3-6 mm, 6-10 mm, respectively, whereas large specimens are rare; (ii) small and medium-size shells are dispersed or grouped in small accumulations comprising 3-10 specimens lacking a common orientation or size selection; large shells are disperse; (iii) the apical part of the phragmocones commonly retains fragile embryonic and early post-hatching parts; (iv) the mechanical abrasion is minor; (v) a large number of shells are “hollow belemnites” lacking the diagenetic filling of the protoconch and the apical chambers of the phragmocones. The above set of characters illuminates a high mortality of juvenile and immature pachybelemnopsein belemnites as well as their fast in situ burial. This suggests that the adults did not live constantly in a shallow-water environment. The studied belemnites support a viewpoint on the adaptation of the embryonic conch of the belemnites for a nekto-pelagic lifestyle of the hatchlings. This may provide their effective dispersal and growing expansion from the late Early Jurassic onwards.

  • 332.
    Doguzhaeva, Larisa
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Mutvei, Harry
    Swedish Museum of Natural History, Department of Paleobiology.
    Connecting stripes: An organic skeletal structure in Sepia from Red Sea2012In: Geobios, ISSN 0016-6995, E-ISSN 1777-5728, Vol. 45, p. 13-17Article in journal (Refereed)
    Abstract [en]

    The skeletal structure, herein termed ‘‘connecting stripes’’, is demonstrated in dried cuttlebones of Sepia (Acanthosepion) savignyi de Blainville from the Gulf of Aqaba, Red Sea, Eilat, Israel. This structure consists of segmented chitinous strip-like sheets covering the outside opening to the cuttlebone chambers. Scanning electron microscope images demonstrate that the connecting stripes are tightly attached to the neighbouring septa along the septal edges and do not continue from one chamber to the next. When broken, they leave band-like remnants along the attachment sites. The connecting stripes consist of fibrous, organic, possibly mainly chitinous, laminas. Chemical analysis using energy dispersive spectrometry shows that the connecting stripes contain C, O, Na, K but lack Ca and P. The connecting stripes show perceptible, usually barely visible micropores with diameter of ca. 0.1 mm; distances between the micropores are 0.2 to 0.3 mm. The connecting stripes in Sepia are similar to connecting rings in bactritoids and ammonoids in having a segmented structure and a non-mineralized, organic composition. The microporosity of connecting stripes observed in Sepia has been also recorded in three genera of Mesozoic ammonoids. The connecting stripes may serve as a transport route of the cameral liquid in and out of the chambers and are considered to be a homologue of the connecting rings in cephalopods with a fully developed siphonal tube.

  • 333.
    Doguzhaeva, Larisa
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Mutvei, Harry
    Swedish Museum of Natural History, Department of Paleobiology.
    The additional external shell layer indicative of "Endocochleate experiments" in some ammonoids2015In: Topics in Geobiology, Vol. 43, no 15, p. 585-609Article in journal (Refereed)
  • 334.
    Doguzhaeva, Larisa
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Mutvei, Harry
    Swedish Museum of Natural History, Department of Paleobiology.
    The Additional External Shell Layers Indicative of “Endocochleate Experiments” in Some Ammonoids2015In: Ammonoid paleobiology: From anatomy to ecology / [ed] Ch. Klug et al., Dordrecht: Springer, 2015, 2nd, p. 585-609Chapter in book (Refereed)
  • 335.
    Doguzhaeva, Larisa
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Summesberger, Herbert
    Museum of Natural History, Vienn.
    Pro-ostraca of Triassic belemnoids (Cephalopoda) from Northern Calcareous Alps, with observations on their mode of preservation in an environment of northern Tethys which allowed for carbonization of non-biomineralized structures.2012In: N. Jb. Geol. Paläont. Abh., Vol. 266, no 1, p. 31-38Article in journal (Refereed)
    Abstract [en]

    A pro-ostracum – the anterior dorsal plate subdivided into three longitudinal fields – is

    developed in Triassic phragmoteuthids (Phragmoteuthis, Breviconoteuthis) and the belemnotheutid? (Lunzoteuthis) but is missing in aulacocerids which have a pro-ostracum-like structure – the dorsal apertural crest with arched growth lines. Two types of pro-ostraca: a Phragmoteuthis-type, characterized by arched growth lines in each field, and a Lunzoteuthis-type, in which the median field has arched growth lines and lateral fields bear converging longitudinal ridges, are distinguished. The pro-ostracum with the ridged lateral fields evidently obtained further rapid development; in the Sinemurian belemnite Nannobelus the ridged lateral fields are already formed by the longitudinally exposed narrow portions of succeeding, overlapping sublayers of the pro-ostracum. This structure apparently enabled efficient mantle/shell linkage that facilitated effective manoeuvring, an active mode of life and global radiation of Jurassic belemnites. Exceptional, large scale, preservation of pro-ostraca in lower Carnian of Schindelberg, Lower Austria, and Raibl, North Italy, was possibly due to the concurrency of (1) an environment of the northern Tethys that allowed for post-mortem carbon substitution of chitin and other non-biomineralized material, such as ink and mantle tissue, and (2) the inorganic-organic composition of pro-ostracum as indicated by micro-laminations typical of chitin-containing material and characterized by alteration of chitinous and carbonate laminas similar to those in cuttlebones of Recent Sepia.

  • 336.
    Doguzhaeva, Larisa
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Weaver, Patricia
    North Carolina Museum of Natural Sciences; U.S.A..
    Ciampaglio, Charles
    Department of Geology, Wright State University−Lake Campus.
    A unique late Eocene coleoid cephalopod Mississaepia from Mississippi, USA: New data on cuttlebone structure, and their phylogenetic implications.2014In: Acta Palaeontologica Polonica, ISSN 0567-7920, E-ISSN 1732-2421, Vol. 59, no 1, p. 147-162Article in journal (Refereed)
    Abstract [en]

    A new family, Mississaepiidae, from the Sepia–Spirula branch of decabrachian coleoids (Cephalopoda), is erected on the basis of the following, recently revealed, morphological, ultrastructural and chemical traits of the cuttlebone in the late Eocene Mississaepia, formerly referred to Belosaepiidae: (i) septa are semi−transparent, largely chitinous (as opposed to all other recorded cephalopods having non−transparent aragonitic septa); (ii) septa have a thin lamello−fibrillar nacreous covering (Sepia lacks nacre altogether, Spirula has fully lamello−fibrillar nacreous septa, ectochochleate cephalopods have columnar nacre in septa); (iii) a siphonal tube is present in early ontogeny (similar to siphonal tube development of the Danian Ceratisepia, and as opposed to complete lack of siphonal tube in Sepia and siphonal tube development through its entire ontogeny in Spirula); (iv) the lamello−fibrillar nacreous ultrastructure of septal necks (similar to septal necks in Spirula); (v) a sub−hemispherical protoconch (as opposed to the spherical protoconchs of the Danian Ceratisepia and Recent Spirula); (vi) conotheca has ventro−lateral extension in early ontogenetic stages (as opposed to Sepia that has no ventro−lateral extention of the conotheca and to Spirula that retains fully−developed phragmocone throughout its entire ontogeny). Chitinous composition of septa in Mississaepia is deduced from (i) their visual similarity to the chitinous semi−transparent flange of Sepia, (ii) angular and rounded outlines and straight compressive failures of the partial septa and mural parts of septa similar to mechanically−damaged dry rigid chitinous flange of Sepia or a gladius of squid, and (iii) organics consistent with [1]−chitin preserved in the shell. The family Mississaepiidae may represent a unknown lineage of the Sepia–Spirula branch of coleoids, a conotheca lacking a nacreous layer being a common trait of the shell of this branch. However, Mississaepiidae is placed with reservation in Sepiida because of similarities between their gross shell morphology (a cuttlebone type of shell) and inorganic−organic composition. In Mississaepia, as in Sepia, the shell contains up to 6% of nitrogen by weight; phosphatised sheets within the dorsal shield may have been originally organic, like similar structures in Sepia; accumulations of pyrite in peripheral zones of aragonitic spherulites and in−between the spherulites of the dorsal shield may also indicate additional locations of organics in the shell of living animal.

  • 337.
    Doguzhaeva, Larisa
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Weaver, Patricia
    North Carolina Museum of Natural Sciences.
    Ciampaglio, Charles N.
    Wright State University−Lake Campus, Department of Geology.
    A unique late Eocene coleoid cephalopod Mississaepia from Mississippi, USA: New data on cuttlebone structure, and their phylogenetic implications.2014In: Acta Palaeontologfica Polonica, Vol. 59, no 1, p. 147-162Article in journal (Refereed)
    Abstract [en]

    A new family, Mississaepiidae, from the SepiaSpirula branch of decabrachian coleoids (Cephalopoda), is erected on the basis of the following, recently revealed, morphological, ultrastructural and chemical traits of the cuttlebone in the late Eocene Mississaepia, formerly referred to Belosaepiidae: (i) septa are semi−transparent, largely chitinous (as opposed to all other recorded cephalopods having non−transparent aragonitic septa); (ii) septa have a thin lamello−fibrillar nacreous covering (Sepia lacks nacre altogether, Spirula has fully lamello−fibrillar nacreous septa, ectochochleate cephalopods have columnar nacre in septa); (iii) a siphonal tube is present in early ontogeny (similar to siphonal tube development of the Danian Ceratisepia, and as opposed to complete lack of siphonal tube in Sepia and siphonal tube development through its entire ontogeny in Spirula); (iv) the lamello−fibrillar nacreous ultrastructure of septal necks (similar to septal necks in Spirula); (v) a sub−hemispherical protoconch (as opposed to the spherical protoconchs of the Danian Ceratisepia and Recent Spirula); (vi) conotheca has ventro−lateral extension in early ontogenetic stages (as opposed to Sepia that has no ventro−lateral extention of the conotheca and to Spirula that retains fully−developed phragmocone throughout its entire ontogeny). Chitinous composition of septa in Mississaepia is deduced from (i) their visual similarity to the chitinous semi−transparent flange of Sepia, (ii) angular and rounded outlines and straight compressive failures of the partial septa and mural parts of septa similar to mechanically−damaged dry rigid chitinous flange of Sepia or a gladius of squid, and (iii) organics consistent with chitin preserved in the shell. The family Mississaepiidae may represent a unknown lineage of the SepiaSpirula branch of coleoids, a conotheca lacking a nacreous layer being a common trait of the shell of this branch. However, Mississaepiidae is placed with reservation in Sepiida because of similarities between their gross shell morphology (a cuttlebone type of shell) and inorganic−organic composition. In Mississaepia, as in Sepia, the shell contains up to 6% of nitrogen by weight; phosphatised sheets within the dorsal shield may have been originally organic, like similar structures in Sepia; accumulations of pyrite in peripheral zones of aragonitic spherulites and in−between the spherulites of the dorsal shield may also indicate additional locations of organics in the shell of living animal.

     

     

     

     

     

  • 338.
    Doguzhaeva, Larisa
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Weis, Robert
    Musee national d’histoire naturelle, Luxembourg.
    Delsate, Domenique
    Musee national d’histoire naturelle, Luxembourg.
    Mariotti, Nino
    Dipartimento di Scienze della Terra, Universita ‘La Sapienza’, Rome, Italy.
    Embryonic shell structure of Early–Middle Jurassic belemnites, and its significance for belemnite expansion and diversification in the Jurassic2014In: Lethaia: an international journal of palaeontology and stratigraphy, ISSN 0024-1164, E-ISSN 1502-3931, Vol. 47, p. 49-65Article in journal (Refereed)
    Abstract [en]

    Early Jurassic belemnites are of particular interest to the study of the evolution of skeletal

    morphology in Lower Carboniferous to the uppermost Cretaceous belemnoids,

    because they signal the beginning of a global Jurassic

    –Cretaceous expansion and diversification

    of belemnitids. We investigated potentially relevant, to this evolutionary pattern,

    shell features of Sinemurian

    –Bajocian Nannobelus, Parapassaloteuthis, Holcobelus

    and

    Pachybelemnopsis from the Paris Basin. Our analysis of morphological, ultrastructural

    and chemical traits of the earliest ontogenetic stages of the shell suggests that

    modified embryonic shell structure of Early

    –Middle Jurassic belemnites was a factor

    in their expansion and colonization of the pelagic zone and resulted in remarkable

    diversification of belemnites. Innovative traits of the embryonic shell of Sinemurian

    Bajocian belemnites include: (1) an inorganic

    –organic primordial rostrum

    encapsulating the protoconch and the phragmocone, its non-biomineralized component,

    possibly chitin, is herein detected for the first time; (2) an organic rich closing

    membrane which was under formation. It was yet perforated and possessed a foramen;

    and (3) an organic rich pro-ostracum earlier documented in an embryonic shell of

    Pliensbachian

    Passaloteuthis. The inorganic–organic primordial rostrum tightly coating

    the protoconch and phragmocone supposedly enhanced protection, without

    increase in shell weight, of the Early Jurassic belemnites against explosion in deepwater

    environment. This may have increased the depth and temperature ranges of

    hatching eggs, accelerated the adaptation of hatchlings to a nektonic mode of life and

    promoted increasing diversity of belemnoids. This study supports the hypothesis that

    belemnite hatchlings were ‘a miniature of the adults’.

  • 339.
    Doguzhaeva, Larisa
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Weis, Robert
    Musee national d’histoire naturelle, Luxembourg.
    Delsate, Dominique
    Musee national d’histoire naturelle, Luxembourg.
    Mariotti, Nino
    Dipartimento di Scienze della Terra, Universita ‘La Sapienza’.
    Embryonic shell structure of Early–Middle Jurassic belemnites, and its significance for belemnite expansion and diversification in the Jurassic.2014In: Lethaia: an international journal of palaeontology and stratigraphy, ISSN 0024-1164, E-ISSN 1502-3931, Vol. 47, p. 49-65, article id DOI 10.1111/let.12037Article in journal (Refereed)
    Abstract [en]

    Early Jurassic belemnites are of particular interest to the study of the evolution of skeletal morphology in Lower Carboniferous to the uppermost Cretaceous belemnoids, because they signal the beginning of a global Jurassic–Cretaceous expansion and diversification of belemnitids. We investigated potentially relevant, to this evolutionary pattern, shell features of Sinemurian–Bajocian Nannobelus, Parapassaloteuthis, Holcobelus and Pachybelemnopsis from the Paris Basin. Our analysis of morphological, ultrastructural and chemical traits of the earliest ontogenetic stages of the shell suggests that modified embryonic shell structure of Early–Middle Jurassic belemnites was a factor in their expansion and colonization of the pelagic zone and resulted in remarkable diversification of belemnites. Innovative traits of the embryonic shell of Sinemurian–Bajocian belemnites include: (1) an inorganic–organic primordial rostrum encapsulating the protoconch and the phragmocone, its non-biomineralized component, possibly chitin, is herein detected for the first time; (2) an organic rich closing membrane which was under formation. It was yet perforated and possessed a foramen; and (3) an organic rich pro-ostracum earlier documented in an embryonic shell of Pliensbachian Passaloteuthis. The inorganic–organic primordial rostrum tightly coating the protoconch and phragmocone supposedly enhanced protection, without increase in shell weight, of the Early Jurassic belemnites against explosion in deep water environment. This may have increased the depth and temperature ranges of hatching eggs, accelerated the adaptation of hatchlings to a nektonic mode of life andpromoted increasing diversity of belemnoids. This study supports the hypothesis thatbelemnite hatchlings were ‘a miniature of the adults’.

  • 340.
    Donadini, Fabio
    et al.
    ETH Zürich.
    Elming, Sten-Åke
    Luleå Tekniska Universitet.
    Tauxe, Lisa
    University of California, La Jolla.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Paleointensity determination on a 1.786 Ga old gabbro from Hoting, Central Sweden2011In: Earth and Planetary Science Letters, ISSN 0012-821X, E-ISSN 1385-013X, Vol. 309, p. 234-248Article in journal (Refereed)
  • 341. Dong, Xi-ping
    et al.
    Cunningham, John A.
    University of Bristol.
    Bengtson, Stefan
    Swedish Museum of Natural History, Department of Paleobiology.
    Thomas, Ceri-Wyn
    Liu, Jianbo
    Stampanoni, Marco
    Donoghue, Philip C.J.
    University of Bristol.
    Embryos, polyps and medusae of the early Cambrian scyphozoan Olivooides.2013In: Proceedings of the Royal Society Biological Sciences Series B, ISSN 0962-8452, Vol. 280, no 2130071, p. 1-8Article in journal (Refereed)
    Abstract [en]

    The Early Cambrian organism Olivooides is known from both embryonic and post-embryonic stages and, consequently, it has the potential to yield vital insights into developmental evolution at the time that animal body plans were established. However, this potential can only be realized if the phylogenetic relationships of Olivooides can be constrained. The affinities of Olivooides have proved controversial because of the lack of knowledge of the internal anatomy and the limited range of developmental stages known. Here, we describe rare embryonic specimens in which internal anatomical features are preserved. We also present a fuller sequence of fossilized developmental stages of Olivooides, including associated specimens that we interpret as budding ephyrae ( juvenile medusae), all of which display a clear pentaradial symmetry. Within the framework of a cnidarian interpretation, the new data serve to pinpoint the phylogenetic position of Olivooides to the scyphozoan stem group. Hypotheses about scalidophoran or echinoderm affinities of Olivooides can be rejected.

  • 342.
    Dong, Xi-ping
    et al.
    Peking University.
    Vargas, Kelly
    University of Bristol.
    Cunningham, John
    Swedish Museum of Natural History, Department of Paleobiology. University of Bristol.
    Zhang, Huaqiao
    Nanjing Institute of Geology and Palaeontology.
    Liu, Teng
    Peking University.
    Chen, Fang
    Peking University.
    Liu, Jianbo
    Peking University.
    Bengtson, Stefan
    Swedish Museum of Natural History, Department of Paleobiology.
    Donoghue, Philip C.J.
    Developmental biology of the early Cambrian cnidarian Olivooides.2016In: Palaeontology, ISSN 0031-0239, E-ISSN 1475-4983, Vol. 59, no 3, p. 387-407Article in journal (Refereed)
    Abstract [en]

    Fossilized embryos afford direct insight into the pattern of development in extinct organisms, providing unique tests of hypotheses of developmental evolution based in comparative embryology. However, these fossils can only be effective in this role if their embryology and phylogenetic affinities are well constrained. We elucidate and interpret the development of Olivooides from embryonic and adult stages and use these data to discriminate among competing interpretations of their anatomy and affinity. The embryology of Olivooides is principally characterized by the development of an ornamented periderm that initially forms externally and is subsequently formed internally, released at the aperture, facilitating the direct development of the embryo into an adult theca. Internal anatomy is known only from embryonic stages, revealing two internal tissue layers, the innermost of which is developed into three transversally arranged walls that partly divide the lumen into an abapertural region, interpreted as the gut of a polyp, and an adapertural region that includes structures that resemble the peridermal teeth of coronate scyphozoans. The anatomy and pattern of development exhibited by Olivooides appears common to the other known genus of olivooid, Quadrapyrgites, which differs in its tetraradial, as opposed to pentaradial symmetry. We reject previous interpretations of the olivooids as cycloneuralians, principally on the grounds that they lack a through gut and introvert, in embryo and adult. Instead we consider the affinities of the olivooids among medusozoan cnidarians; our phylogenetic analysis supports their classification as totalgroup Coronata, within crown-Scyphozoa. Olivooides and Quadrapyrgites evidence a broader range of life history strategies and bodyplan symmetry than is otherwise commonly represented in extant Scyphozoa specifically, and Cnidaria more generally.

  • 343. Donoghue, Philip C.J.
    et al.
    Cunningham, John
    Swedish Museum of Natural History, Department of Paleobiology.
    Dong, Xi-ping
    Peking University.
    Bengtson, Stefan
    Swedish Museum of Natural History, Department of Paleobiology.
    Embryology in deep time.2015In: Evolutionary Developmental Biology of Invertebrates 1 / [ed] Wanninger, Andreas, Wien: Springer Science+Business Media B.V., 2015, p. 45-63Chapter in book (Refereed)
    Abstract [en]

    For anyone who has cared for animal embryos, it beggars belief that these squishy cellular aggregates could be fossilised. Hence, with hindsight, it is possible to empathise with palaeontologists who found such fossils and, in their naming of Olivooides, Pseudooides, etc., drew attention to their likeness to animal eggs and embryos but without going so far as to propose such an interpretation. However, in 1994, Zhang Xi-guang and Brian Pratt described microscopic balls of calcium phosphate from Cambrian rocks of China, one or two of which preserved polygonal borders that resembled blastomeres on the surface of an early cleaving animal embryo. In retrospect, these fossils are far from remarkable, some of them may not be fossils at all, and it is not as if anyone ever conceived Cambrian animals as having lacked an embryology. But Zhang Xi-guang and Brian Pratt dared the scientific world, not least their fellow palaeontologists, to believe that the fragile embryonic stages of invertebrate animals could be fossilised, that there was a fossil record of animal embryology, that this record hailed from the interval of time in which animal body plans were first established, and that it had been awaiting discovery in the rocks, for want of looking. The proof of this concept came a few years later, when phosphatised Cambrian fossils from China and Siberia were shown to display indisputable features of animal embryonic morphologies. In the case of Olivooides, a series of developmental stages from cleavage to morphogenesis through hatching and juvenile growth could be tentatively identified; in Markuelia, the coiled-up body of an annulated worm-like animal could be clearly seen within its fertilisation envelope.

  • 344. Drake, H.
    et al.
    Tullborg, E.L.
    Whitehouse, Martin J.
    Swedish Museum of Natural History, Department of Geology.
    Sandberg, B.
    Blomfeldt, T.
    Åström, M.E.
    Extreme fractionation and micro-scale variation of sulphur isotopes during bacterial sulphate reduction in deep groundwater systems.2015In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 161, p. 1-18Article in journal (Refereed)
    Abstract [en]

    This study conducted at the Äspö Hard Rock Laboratory, SE Sweden, determines the extent and mechanisms of sulphur-isotope fractionation in permanently reducing groundwater in fractured crystalline rock. Two boreholes >400 m below the ground surface were investigated. In the 17-year-old boreholes, the Al instrumentation pipes had corroded locally (i.e., Al-[oxy]hydroxides had formed) and minerals (i.e., pyrite, iron monosulphide, and calcite) had precipitated on various parts on the equipment. By chemically and isotopically comparing the precipitates on the withdrawn instrumentation and the borehole waters, we gained new insight into the dynamics of sulphate reduction, sulphide precipitation, and sulphur-isotope fractionation in deep-seated crystalline-rock settings. An astonishing feature of the pyrite is its huge variability in δ34S, which can exceed 100‰ in total (i.e., −47.2 to +53.3‰) and 60‰ over 50 μm of growth in a single crystal. The values at the low end of the range are up to 71‰ lower than measured in the dissolved sulphate in the water (20–30‰), which is larger than the maximum difference reported between sulphate and sulphide in pure-culture experiments (66‰) but within the range reported from natural sedimentary settings. Although single-step reduction seems likely, further studies are needed to rule out the effects of possible S disproportionation. The values at the high end of the range (i.e., high δ34Spy) are much higher than could be produced from the measured sulphate under any biogeochemical conditions. This strongly suggests the development of closed-system conditions near the growing pyrite, i.e., the rate of sulphate reduction exceeds the rate of sulphate diffusion in the local fluid near the pyrite, causing the local aqueous phase (and thus the forming pyrite) to become successively enriched in heavy S (34S). Consequently, the δ34S values of the forming pyrite become exceptionally high and strongly decoupled from the δ34S values of the sulphate in the bulk fluid. The Al-(oxy)hydroxide and calcite precipitates are explained by a combination of deposit and galvanic corrosion initiated by Al corrosion by H2S produced by sulphate-reducing microorganisms.

  • 345. Drake, Henrik
    et al.
    Heim, Christine
    Roberts, N.M.W
    Zack, Tomas
    Tillberg, M
    Broman, Curt
    Ivarsson, Magnus
    Swedish Museum of Natural History, Department of Paleobiology.
    Whitehouse, Martin
    Åström, M
    Isotopic evidence for microbial production and consumption of methane in the upper continental crust throughout the Phanerozoic eon2017In: Earth and Planetary Science Letters, Vol. 470, p. 108-118Article in journal (Refereed)
  • 346.
    Drake, Henrik
    et al.
    Linnæus University, Department of Biology and Environmental Science, 39182 Kalmar, Sweden.
    Ivarsson, Magnus
    Swedish Museum of Natural History, Department of Paleobiology. University of Southern Denmark, Department of Biology and Nordic Center for Earth Evolution, Campusvej 55, Odense M, DK-5230, Denmark.
    The role of anaerobic fungi in fundamental biogeochemical cycles in the deep biosphere2018In: Fungal Biology Reviews, ISSN 1749-4613, E-ISSN 1878-0253, Vol. 32, p. 20-25Article in journal (Refereed)
    Abstract [en]

    A major part of the biologic activity on Earth is hidden underneath our feet in an environment coined the deep biosphere which stretches several kilometers down into the bedrock. The knowledge about life in this vast energy-poor deep system is, however, extremely scarce, particularly for micro-eukaryotes such as fungi, as most studies have focused on prokaryotes. Recent findings suggest that anaerobic fungi indeed thrive at great depth in fractures and cavities of igneous rocks in both the oceanic and the continental crust. Here we discuss the potential importance of fungi in the deep biosphere, in particular their involvement in fundamental biogeochemical processes such as symbiotic relationships with prokaryotes that may have significant importance for the overall energy cycling within this vast subsurface realm. Due to severe oligotrophy, the prokaryotic metabolism at great depth in the crust is very slow and dominantly autotrophic and thus dependent on e.g. hydrogen gas, but the abiotic production of this gas is thought to be insufficient to fuel the deep autotrophic biosphere. Anaerobic fungi are heterotrophs that produce hydrogen gas in their metabolism and have therefore been put forward as a hypothetical provider of this substrate to the prokaryotes. Recent in situ findings of fungi and isotopic signatures within co-genetic sulfide minerals formed from bacterial sulfate reduction in the deep continental biosphere indeed seem to confirm the fungi-prokaryote hypothesis. This suggests that fungi play a fundamental biogeochemical role in the deep biosphere.

  • 347. Drake, Henrik
    et al.
    Ivarsson, Magnus
    Swedish Museum of Natural History, Department of Paleobiology.
    Bengtson, Stefan
    Swedish Museum of Natural History, Department of Paleobiology.
    Heim, Christine
    Siljeström, Sandra
    Whitehouse, Martin
    Swedish Museum of Natural History, Department of Geology.
    Broman, Curt
    Belivanova, Veneta
    Swedish Museum of Natural History, Department of Paleobiology.
    Åström, Mats E.
    Anaerobic consortia of fungi and sulfate reducing bacteria in deep granite fractures2017In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 8, no 55, p. 1-9Article in journal (Refereed)
    Abstract [en]

    The deep biosphere is one of the least understood ecosystems on Earth. Although most microbiological studies in this system have focused on prokaryotes and neglected microeukaryotes, recent discoveries have revealed existence of fossil and active fungi in marine sediments and sub-seafloor basalts, with proposed importance for the subsurface energy cycle. However, studies of fungi in deep continental crystalline rocks are surprisingly few. Consequently, the characteristics and processes of fungi and fungus-prokaryote interactions in this vast environment remain enigmatic. Here we report the first findings of partly organically preserved and partly mineralized fungi at great depth in fractured crystalline rock (-740 m). Based on environmental parameters and mineralogy the fungi are interpreted as anaerobic. Synchrotron-based techniques and stable isotope microanalysis confirm a coupling between the fungi and sulfate reducing bacteria. The cryptoendolithic fungi have significantly weathered neighboring zeolite crystals and thus have implications for storage of toxic wastes using zeolite barriers.

  • 348.
    Drake, Henrik
    et al.
    Linnæus University, Department of Biology and Environmental Science, 39182 Kalmar, Sweden.
    Ivarsson, Magnus
    Swedish Museum of Natural History, Department of Paleobiology. University of Southern Denmark, Department of Biology and Nordic Center for Earth Evolution, Campusvej 55, Odense M, DK-5230, Denmark.
    Tillberg, Mikael
    Department of Biology and Environmental Science, Linnaeus University, 392 31 Kalmar, Sweden.
    Whitehouse, Martin
    Swedish Museum of Natural History, Department of Geology.
    Kooijman, Ellen
    Swedish Museum of Natural History, Department of Geology.
    Ancient microbial activity in deep hydraulically conductive fracture zones within the Forsmark target area for deep geological nuclear waste disposal, Sweden2018In: Geosciences, Vol. 8, article id 211Article in journal (Refereed)
    Abstract [en]

    Recent studies reveal that organisms from all three domains of life—Archaea, Bacteria, and even Eukarya—can thrive under energy-poor, dark, and anoxic conditions at large depths in the fractured crystalline continental crust. There is a need for an increased understanding of the processes and lifeforms in this vast realm, for example, regarding the spatiotemporal extent and variability of the different processes in the crust. Here, we present a study that set out to detect signs of ancient microbial life in the Forsmark area—the target area for deep geological nuclear waste disposal in Sweden. Stable isotope compositions were determined with high spatial resolution analyses within mineral coatings, and mineralized remains of putative microorganisms were studied in several deep water-conducting fracture zones (down to 663 m depth), from which hydrochemical and gas data exist. Large isotopic variabilities of 13Ccalcite (􀀀36.2 to +20.2‰V-PDB) and 34Spyrite (􀀀11.7 to +37.8‰V-CDT) disclose discrete periods of methanogenesis, and potentially, anaerobic oxidation of methane and related microbial sulfate reduction at several depth intervals. Dominant calcite–water disequilibrium of 18O and 87Sr/86Sr precludes abundant recent precipitation. Instead, the mineral coatings largely reflect an ancient archive of episodic microbial processes in the fracture system, which, according to our microscale Rb–Sr dating of co-genetic adularia and calcite, date back to the mid-Paleozoic. Potential Quaternary precipitation exists mainly at ~400 m depth in one of the boreholes, where mineral–water compositions corresponded.

  • 349. Drake, Henrik
    et al.
    Ivarsson, Magnus
    Tillberg, Mikael
    Whitehouse, Martin
    Swedish Museum of Natural History, Department of Geology.
    Kooijman, Ellen
    Swedish Museum of Natural History, Department of Geology.
    Ancient Microbial Activity in Deep Hydraulically Conductive Fracture Zones within the Forsmark Target Area for Geological Nuclear Waste Disposal, Sweden2018In: Geosciences, Vol. 8, no 211Article in journal (Refereed)
    Abstract [en]

    Recent studies reveal that organisms from all three domains of life—Archaea, Bacteria, and even Eukarya—can thrive under energy-poor, dark, and anoxic conditions at large depths in the fractured crystalline continental crust. There is a need for an increased understanding of the processes and lifeforms in this vast realm, for example, regarding the spatiotemporal extent and variability of the different processes in the crust. Here, we present a study that set out to detect signs of ancient microbial life in the Forsmark area—the target area for deep geological nuclear waste disposal in Sweden. Stable isotope compositions were determined with high spatial resolution analyses within mineral coatings, and mineralized remains of putative microorganisms were studied in several deep water-conducting fracture zones (down to 663 m depth), from which hydrochemical and gas data exist. Large isotopic variabilities of δ13Ccalcite (−36.2 to +20.2‰ V-PDB) and δ34Spyrite (−11.7 to +37.8‰ V-CDT) disclose discrete periods of methanogenesis, and potentially, anaerobic oxidation of methane and related microbial sulfate reduction at several depth intervals. Dominant calcite–water disequilibrium of δ18O and 87Sr/86Sr precludes abundant recent precipitation. Instead, the mineral coatings largely reflect an ancient archive of episodic microbial processes in the fracture system, which, according to our microscale Rb–Sr dating of co-genetic adularia and calcite, date back to the mid-Paleozoic. Potential Quaternary precipitation exists mainly at ~400 m depth in one of the boreholes, where mineral–water compositions corresponded.

  • 350.
    Drake, Henrik
    et al.
    Department of Biology and Environmental Science, Linnaeus University, 39231 Kalmar, Sweden.
    Mathurin, Frédéric A.
    Department of Biology and Environmental Science, Linnaeus University, 39231 Kalmar, Sweden.
    Zack, Thomas
    Department of Earth Science, University of Gothenburg, Gothenburg, Sweden.
    Schäfer, Thorsten
    Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal, 76021 Karlsruhe, Germany.
    Nick MW, Roberts
    NERC Isotope Geosciences Laboratory, British Geological Survey, Nottingham NG12 5GG, U.K..
    Whitehouse, Martin
    Swedish Museum of Natural History, Department of Geology.
    Karlsson, Andreas
    Swedish Museum of Natural History, Department of Geology.
    Broman, Curt
    Department of Geological Sciences, Stockholm University, Stockholm 106 91, Sweden.
    Mats E., Åström
    Department of Biology and Environmental Science, Linnaeus University, 39231 Kalmar, Sweden.
    Incorporation of Metals into Calcite in a Deep Anoxic Granite Aquifer2018In: Environmental Science and Technology, ISSN 1086-931X, E-ISSN 1520-6912, Vol. 52, no 2, p. 293-502Article in journal (Refereed)
    Abstract [en]

    Understanding metal scavenging by calcite in deep aquifers in granite is of importance for deciphering and modeling hydrochemical fluctuations and water–rock interaction in the upper crust and for retention mechanisms associated with underground repositories for toxic wastes. Metal scavenging into calcite has generally been established in the laboratory or in natural environments that cannot be unreservedly applied to conditions in deep crystalline rocks, an environment of broad interest for nuclear waste repositories. Here, we report a microanalytical study of calcite precipitated over a period of 17 years from anoxic, low-temperature (14 °C), neutral (pH: 7.4–7.7), and brackish (Cl: 1700–7100 mg/L) groundwater flowing in fractures at >400 m depth in granite rock. This enabled assessment of the trace metal uptake by calcite under these deep-seated conditions. Aquatic speciation modeling was carried out to assess influence of metal complexation on the partitioning into calcite. The resulting environment-specific partition coefficients were for several divalent ions in line with values obtained in controlled laboratory experiments, whereas for several other ions they differed substantially. High absolute uptake of rare earth elements and U(IV) suggests that coprecipitation into calcite can be an important sink for these metals and analogousactinides in the vicinity of geological repositories.

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