204 research outputs found

    Silurian agglutinated foraminifera from the Dingle Peninsula, Ireland

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    Viene qui descritta per la prima volta una associazione di foraminiferi agglutinanti all’interno di calcari siluriani della Penisola di Dingle, Contea di Kerry, Irlanda sud-occidentale. La collezione è stata rinvenuta nel residuo di campioni trattati per la preparazione di conodonti. I foraminiferi sono dominati da tubotalamidi (Rectoammodiscus e rari Sansabaina), mentre più rari sono i monotalamidi (Psammosiphonella e Psammosphaera). A livello speci co l’associazione presente in Irlanda è identica a quella descritta in precedenza nel Siluriano del Nord America, anche se presenta minore diversità. Tutte le specie rinvenute hanno una lunga distribuzione stratigra ca, e quindi ricoprono un signi cato limitato per correlazioni stratigra che. La fauna a conodonti ritrovata nei campioni ha permesso una attribuzione dei foraminiferi agglutinanti alla parte iniziale del Ludlow.An assemblage of primitive agglutinated foraminifera is reported for the first time from Silurian limestones from the Dingle Peninsula, Ireland. The assemblage is dominated by tubothalamids (Rectoammodiscus and rare Sansabaina), with less abundant monothalamids (Psammosiphonella and Psammosphaera). At the species level, the agglutinated foraminiferal assemblage is identical to those described previously from the Silurian of North America but is of lower diversity. The foraminiferal assemblage has limited potential for stratigraphic correlation as long-ranging taxa are present. The co-occurring conodont fauna enables an assignment to the early Ludlow

    Reclaiming Lost and Disregarded Voices: In the Vine Country, Memory, Female Independence and Wine Writing in the Victorian Age

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    The historical role of Bordeaux and the consumption of claret throughout Georgian and Victorian Ireland has been explored. That fine red wines were drunk and enjoyed by the ascendancy in Ireland is not unusual. What is unusual, however, is the place of In the Vine Country,a Somerville-and-Ross travelogue commissioned and written for the Lady’s Pictorial: A Newspaper for the Home, an illustrated weekly paper founded in 1880, aimed at middle-class women in Victorian era Great Britain and Ireland. From Castletownshend, Co. Cork and Oughterard, Co. Galway, cousins Edith Œ. Somerville (1858-1949), and Violet Martin (1862-1915) were writing partners. Of the Anglo-Irish protestant class, they hold an ambivalent place in the Irish literary canon; as identity politics and “othering” are among factors at play in their becoming lost and disregarded voices. Their commissioning editor dispatched them to the vineyards of the Médoc to document the vintage of 1891; In the Vine Country is the collection of their illustrated weekly articles published from October to December 1892. Wine holds deep symbolism (then and now) and has been used as a means of establishing status and making social distinctions. The role of fine red wine in In the Vine Country is symbolic of this period of upheaval and social change in colonial Ireland, and of the changing roles of middle-class women. This paper draws on the subtle and overt tensions of two single Irish women travelling alone from West Cork to the Médoc in the late 1800s. Both trauma and tradition are explored through the lenses of women and wine consumption; changing gender politics; and the “othering” of both wine as a distinct beverage and the protestant classes in Catholic Ireland. The question of whether Irish women in the ascendancy may have had more social freedoms than their English counterparts of the period becomes apparent

    Anatomy of the Ediacaran rangeomorph Charnia masoni

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    The Ediacaran macrofossil Charnia masoni Ford is perhaps the most iconic member of the Rangeomorpha: a group of seemingly sessile, frondose organisms that dominates late Ediacaran benthic, deep‐marine fossil assemblages. Despite C. masoni exhibiting broad palaeogeographical and stratigraphical ranges, there have been few morphological studies that consider the variation observed among populations of specimens derived from multiple global localities. We present an analysis of C. masoni that evaluates specimens from the UK, Canada and Russia, representing the largest morphological study of this taxon to date. We describe substantial morphological variation within C. masoni and present a new morphological model for this species that has significant implications both for interpretation of rangeomorph architecture, and potentially for existing taxonomic schemes. Previous reconstructions of Charnia include assumptions regarding the presence of structures seen in other rangeomorphs (e.g. an internal stalk) and of homogeneity in higher order branch morphology; observations that are not borne out by our investigations. We describe variation in the morphology of third and fourth order branches, as well as variation in gross structure near the base of the frond. The diagnosis of Charnia masoni is emended to take account of these new features. These findings highlight the need for large‐scale analyses of rangeomorph morphology in order to better understand the biology of this long‐enigmatic group

    A demonstration of an affinity between pyrite and organic matter in a hydrothermal setting

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    One of the key-principles of the iron-sulphur world theory is to bring organic molecules close enough to interact with each other, using the surface of pyrite as a substrate in a hydrothermal setting. The present paper explores the relationship of pyrite and organic matter in a hydrothermal setting from the geological record; in hydrothermal calcite veins from Carboniferous limestones in central Ireland. Here, the organic matter is accumulated as coatings around, and through, pyrite grains. Most of the pyrite grains are euhedral-subhedral crystals, ranging in size from ca 0.1-0.5 mm in diameter, and they are scattered throughout the matrix of the vein calcite. The organic matter was deposited from a hydrothermal fluid at a temperature of at least 200°C, and gives a Raman signature of disordered carbon. This study points to an example from a hydrothermal setting in the geological record, demonstrating that pyrite can have a high potential for the concentration and accumulation of organic materials

    Early carboniferous brachiopod faunas from the Baoshan block, west Yunnan, southwest China

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    38 brachiopod species in 27 genera and subgenera are described from the Yudong Formation in the Shidian-Baoshan area, west Yunnan, southwest China. New taxa include two new subgenera: Unispirifer (Septimispirifer) and Brachythyrina (Longathyrina), and seven new species: Eomarginifera yunnanensis, Marginatia cylindrica, Unispirifer (Unispirifer) xiangshanensis, Unispirifer (Septimispirifer) wafangjieensis, Brachythyrina (Brachythyrina) transversa, Brachythyrina (Longathyrina) baoshanensis, and Girtyella wafangjieensis. Based on the described material and constraints from associated coral and conodont faunas, the age of the brachiopod fauna from the Yudon Formation is considered late Tournaisian (Early Carboniferous), with a possibility extending into earlyViseacutean.<br /

    The correlation potential of magnetic susceptibility and outcrop gamma-ray logs at Tournaisian-Viséan boundary sections in western Europe

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    We have measured five deep-water carbonate and carbonate-siliciclastic sections at the Tournaisian-Visean (Tn/V) boundary in western Europe, using petrophysical outcrop logging techniques (gamma-ray spectrometry /GRS/ and magnetic susceptibility /MS/). The aim was to trace correlatable log patterns across the flanks of the London-Brabant Massif from eastern Ireland to western Germany. Both GRS and MS logging proved useful for long-distance (up to similar to 1000 km) correlation. The log patterns can be interpreted in terms of sea-level fluctuations. A late Tournaisian regression, a sequence boundary at the Tn/V boundary, early Visean lowstand systems tract and an overlying transgressive to regressive succession can be identified from the GRS and MS logs. The Tn/V sequence boundary can be correlated with exposure features and karstic surfaces in the up-dip shallow-water settings at the boundary between sequence 4 and 5 of Hance et al. (2001, 2002). This indicates that sea-level fluctuations around the Tn/V boundary were synchronous and traceable on the flanks of the London-Brabant Massif. The GRS-based logging has a greater correlation potential than MS as it can be applied in a broad spectrum of facies and depositional settings. In certain sections, the MS signal shows an increasing trend during transgression and a decreasing during regression, which is opposite to the MS paradigm from shallow-water carbonate platform settings. These trends are assumed to result from landward/basinward facies shifts of low-productivity carbonate ramp systems. Lowstand shedding of carbonate tempestites and turbidites results in low MS values while during sea-level rise the ramp systems backstep, developing retrograding facies successions in their distal parts, which are associated with upward-increasing MS values

    Figure 2: Stereom microstructure of the Late Ordovician pleurocystitids and a recent crinoid Metacrinus rotundus

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    Pleurocystitid rhombiferans are among the most unusual echinoderms whose mode of life has been long debated. These echinoderms are usually interpreted as vagile epibenthic echinoderms, moving over the sea bottom by means of a flexible stem. Although their life habits and posture are reasonably well understood, the mechanisms that control the movement of stem are highly controversial. Specifically, it is unknown whether the stem flexibility was under the control of muscles or ligamentary mutable collagenous tissues (MCTs). Here, we reconstruct palaeoanatomy of the two Ordovician pleurocystitid rhombiferans (Pleurocystites and Amecystis) based on stereom microstructure. We show that the articular facets of columnals in pleurocystitid rhombiferans are composed of fine labyrinthic stereom. Comparison with modern echinoderms suggests that this type of stereom was associated with muscles implying that their stem was a muscular locomotory organ supporting an active mode of life

    Phylogeny and Biogeography of Hawkmoths (Lepidoptera: Sphingidae): Evidence from Five Nuclear Genes

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    The 1400 species of hawkmoths (Lepidoptera: Sphingidae) comprise one of most conspicuous and well-studied groups of insects, and provide model systems for diverse biological disciplines. However, a robust phylogenetic framework for the family is currently lacking. Morphology is unable to confidently determine relationships among most groups. As a major step toward understanding relationships of this model group, we have undertaken the first large-scale molecular phylogenetic analysis of hawkmoths representing all subfamilies, tribes and subtribes.The data set consisted of 131 sphingid species and 6793 bp of sequence from five protein-coding nuclear genes. Maximum likelihood and parsimony analyses provided strong support for more than two-thirds of all nodes, including strong signal for or against nearly all of the fifteen current subfamily, tribal and sub-tribal groupings. Monophyly was strongly supported for some of these, including Macroglossinae, Sphinginae, Acherontiini, Ambulycini, Philampelini, Choerocampina, and Hemarina. Other groupings proved para- or polyphyletic, and will need significant redefinition; these include Smerinthinae, Smerinthini, Sphingini, Sphingulini, Dilophonotini, Dilophonotina, Macroglossini, and Macroglossina. The basal divergence, strongly supported, is between Macroglossinae and Smerinthinae+Sphinginae. All genes contribute significantly to the signal from the combined data set, and there is little conflict between genes. Ancestral state reconstruction reveals multiple separate origins of New World and Old World radiations.Our study provides the first comprehensive phylogeny of one of the most conspicuous and well-studied insects. The molecular phylogeny challenges current concepts of Sphingidae based on morphology, and provides a foundation for a new classification. While there are multiple independent origins of New World and Old World radiations, we conclude that broad-scale geographic distribution in hawkmoths is more phylogenetically conserved than previously postulated
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