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Silurian anoxic events at the Cellon section (Austria) through an ichnofabric eye
No full textSilurian ichnofabrics are preliminary described from the Silurian Cellon Section of the Austrian Carnic Alps
Life in an Artinskian (Cisuralian) Permian megacaldera: Benthic palaeoecology in the shadow of the Bolzano Supervolcano (Athesian Volcanic District, Italy)
No full textPermian lobed Zoophycos as the product of the terrestrialization process: Behavioral innovation in the Tahkandit Limestone (Yukon River, Alaska, USA)
Full text linkPaleontological survey in the remote Yukon-Charley Rivers National Preserve in Alaska led to the discovery of
lobed Zoophycos from the lower Tahkandit Limestone (informally named Sandstone unit), an interval characterized
by grayish-green glauconitic sandstone and conglomerate of coastal origin. The studied Zoophycos consists
of a lobate skirt-like spreite bounded by a marginal tube. Smaller tongue-shaped lobes branch off from larger
parent lobes that share the same tongue-like shape. Sedimentological features, together with body fossils and
associated trace fossils (Planolites, Chondrites), indicate a shoreface habitat for the Zoophycos producer. This
shallow-marine environmental setting is in contrast with the deeper bathymetries in which lobed Zoophycos are
recovered in post-Palaeozoic times. The producer of the lobed Zoophycos of the Yukon River is interpreted as a
deposit-feeder that used sensory-driven, directed search for locating heterogeneously distributed trophic resources.
The Zoophycos producer filled its burrow with Coprolus-like fecal pellets, possibly complementing deposit
feeding with microbial gardening and/or food caching. Data presented here provide useful insight into the
morphological evolution and bathymetric distribution of Zoophycos, suggesting two ‘Golden Ages’ for lobed
Zoophycos: (1) Carboniferous–Permian and (2) Cretaceous–Neogene. This stratigraphic distribution supports the
important ecological role of major terrestrialization events, that are, the Palaeozoic expansion of land plants and
the Mesozoic expansion of angiosperms. The consequent increased input of nutrients to coastal areas was an
important contributor to declining trends in porewater oxygen concentrations. This phenomenon favored
adaptive traits to exploit nutrient-rich but oxygen-poor niches, among which the U-shaped marginal tube of
lobed Zoophycos was an efficient adaptation to bring oxygenated water into low-oxygen substrates
The earliest evidence of true crabs? Insights on the evolution of Brachyura from an exceptional exposure of Carnian Psilonichnus (Upper Triassic, Braies, Dolomites, Italy)
No full textA new exceptionally exposed ichnofauna is reported from the Upper Triassic Travenanzes Formation of Braies in the Dolomites (Italy). The ichnosite is extraordinary in that it provides a continuous exposure of 32,000 m2 of intensely bioturbated dolostone. The bioturbated surface is characterized by vertical burrows (Psilonichnus upsilon) occurring at a density of 5 openings / m2. With more than 160,000 burrow openings, the Braies ichnosite preserves the largest exposure ever described for Psilonichnus. The Psilonichnus-bearing horizons represent a carbonate tidal flat that bordered an arid coastal plain, as evidenced by facies analysis and confirmed by the presence of Taenidium barretti. Comparison with modern ocypodid burrows indicates that the Psilonichnus from Braies are compatible with a crab tracemaker (Decapoda: Brachyura), which would represent the earliest fossil evidence for true crabs, although other arthropods cannot be fully discounted as the producers
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
A Paleogene mixed carbonate-siliciclastic system in the western Tethys. Spectral gamma-ray as a tool for the reconstruction of paleoclimate and transgressive-regressive cycles
Full text linkThe mixed carbonate-siliciclastic ramps of the Dauphinois-Provençal domain in northwest Italy are characterized by a common development process during the Paleogene. Spectral gamma-ray (SGR) analysis indicates the concentration of potassium (K), uranium (U), and thorium (Th) in the total gamma-ray signal, permitting the identification of subtle stratigraphic compositional trends, sedimentary minerals, paleoclimatic conditions, and the individualization of lithofacies characters through the stacking pattern cycles. This study integrates known lithological and fossil content analysis of the section with new independent data from the spectral gamma-ray (SGR) to explore the paleoclimate and stacking patterns for defining large-scale depositional cycles along a Paleogene succession in the southwestern Alps. The differences between the outcropping Microcodium Formation and the Capo Mortola Calcarenite Formation are indicated by the SGR, conventionally shown on a linear scale as American Petroleum Institute (API) units, i.e., Th/U, and Th/K ratios. Our data indicate lithofacies associated with normal marine to continental conditions and the presence of abundant smectite, rather than kaolinite, suggesting that the prevailing climate was characterized by prolonged dry periods. Furthermore, the SGR (API) reconstruction of the overall short cycles reflects a progradational and/or retrogradational stacking geometry that accumulated throughout the whole succession. However, the use of the derivative trend analysis (DTA) of the SGR indicates the establishment of long cycles in both formations. The short cycles observed in the Capo Mortola Calcarenite Formation are of particular importance because they characterize the marine transgression of the middle-upper Eocene, transgressive upon the Upper Cretaceous beds, and permit pinpointing the onset of the drowning ramp, which can be correlated regionally with sections spanning from the French-Italian Maritime Alps to the France-Switzerland border
Buildings that ‘Speak’: Ichnological Geoheritage in 1930s Buildings in Piazza della Vittoria (Genova, Italy)
No full textThe geoheritage value of sedimentary building stones has mainly focused on physical sedimentary structures and body fossils. By
contrast, little attention has been placed on the geoheritage significance of ichnofabrics, which are the sedimentary fabrics that
have been reworked by organisms. This study aims to fill this gap by analysing the ichnofabric found on the buildings of Piazza
della Vittoria, in Genova (Italy). Here, unusually visible and well-preserved specimens of the fossil burrow Bichordites are
observed on the historical buildings designed by Marcello Piacentini, one of the local most prominent architects of the 1930s. The
Bichordites of Piazza della Vittoria are winding meniscate burrows with a central string-like structure. Here, we interpret this
ichnofabric as the result of the activity of a community of echinoids bioturbating a sand wave system. We have also located the
historical quarry that provided material for the studied buildings with the same ichnofossils exposed. Surprisingly, the cuts on
display on the buildings are much nicer than those in the outcrops and more taxon specific characteristics can be observed just on
the tiles rather than in the field. For all these reasons, the geoheritage value of the Piazza della Vittoria ichnofabric relies in its
unique scientific significance, the cultural value, and its potential future applications in research, teaching, urban geotourism and
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