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AN INSIGHT INTO THE SYSTEMATICS OF PLICATOSTYLIDAE (BIVALVIA), WITH A DESCRIPTION OF PACHYGERVILLIA ANGUILLAENSIS N. GEN. N. SP. FROM THE LITHIOTIS FACIES (LOWER JURASSIC) OF ITALY
Full text linkThe Lithiotis facies represents an Early Jurassic global bioevent characterized by a remarkable spread of gregarious bivalves, which produced large sedimentary bodies in tropical shallow-water marine environments. The most peculiar and common genera Lithiotis, Cochlearites and Lithioperna, with aberrant and extremely elongated or strongly flattened shells, have been studied since the second half of the nineteenth century. Despite numerous systematic studies, their phylogenetic relationship with the other bivalve families is still uncertain. The Lithiotis facies yields other bivalve genera, among which a large multivincular mytiloid, provisionally determined as Isognomon (Mytiloperna) sp. ind. or Mytiloperna sp., is recorded in the literature. This taxon is here studied from a systematic point of view to clarify its taxonomic position and solve the open nomenclature adopted in the past. Here, we propose a new genus Pachygervillia and a new species Pachygervillia anguillaensis. The stratotype is located in the lower part of the Rotzo Formation (Calcari Grigi Group, Lower Jurassic), while the type locality is in the Lessini Mountains (Verona Province, Trento Platform, Southern Alps). This new species is characterized by a thick aragonitic inner shell layer with a fibrous, irregular, spherulitic, prismatic microstructure combined with a nacreous middle layer, both also occurring in species of the genera Lithiotis and Cochlearites of the family Plicatostylidae. This microstructural layering is here proposed as the main taxonomic character of the family, which is here emended and divided into the following two subfamilies: Plicatostylinae, yielding Lithiotis and Cochlearites with stick-like shells, and Pachygervilliinae nov. subfam., yielding Gervilleioperna, Lithioperna, Pachygervillia n. gen., and Pachyperna, previously placed within the subfamily Isognomoninae.
Replication data for "Brachiopods as archives of intrannual, annual and interannual environmental variations"
No full text1) Table S1. Excel file in xlsx format with stable isotope and trace elemental data of seven specimens belonging to three species of modern brachiopods. Stable isotope data have been obtained using an Isoprime dual inlet mass spectrometer plus Multiprep device, whereas trace elemental data using an Agilent 8900 QQQ-ICP-MS. Sheet 1 of the excel file ("specimens") contains information on the type of analysis performed on each specimens and the environmental data of the sampling locality for each species. Excel file composed of 8 sheets. Each Excel sheet refers to a species (L. uva 52, L. uva 58, L. neozelanica 60, L. neozelanica 56, G.vitreus 5, G. vitreus 7V, G. vitreus 7D) and contains columns with numerical values: δ13C ‰ VPDB, δ18O‰ VPDB and trace elements, where available.
2) Table S2. Excel file in xlsx format with data related to the linear and curvatur length, and the length of the growth increments on the shell external surface calculated on 31 specimens of G. vitreus and two specimens of L. uva using using a stereomicroscope Motic SMZ-171-TLed. Excel file composed of 33 sheets.
3) The README file contains the instructions, the software and the data to reproduce the main results of the study. The analysis has been performed using python.
The folder "Brachiopods_as_archives_of_intra_and_interannual_environmental_variations" contains the following subfolders:
- data: Contains the isotope data stored in an Excel file.
- notebooks: Includes Python notebooks for reproducing the main results.
- lib: Contains Python files with auxiliary methods used in the notebooks.
- results: Stores the figures generated by the notebooks.
- environmental.yaml: Yaml file used for building the conda environement for the python software.
Contents of the data folder:
- Isotopi brach x VBG.xlsx: The file is an Excel file in xlsx format containing the isotope data for different species. Each Excel sheet refers to a species (L. uva 52, L. uva 58, L. uva A+B, L. neozelanica 60, L. neozelanica 56, G.vitreus 5, G. vitreus 7 II e III, G. vitreus 7 only III, M. sanguinea K, Gryphus media) and has data for the ventral and dorsal valves.
Each sheet contains the species data as K, Sinf and equilibrium field as numeric data. In addition each sheet contains 3 columns with numerical values: δ13C ‰ VPDB, δ18O‰ VPDB and St lineare. These columns respectively contains the isotope data for Carbon and Oxygen, and the measured lenght increments.
Contents of the notebooks folder:
- paper_figures.ipynb: Generates the main figures, including the isotope time series and power spectra plotted against the 95% confidence level curve.
- supplementary_paper_figures.ipynb: Produces supplementary figures, including tests on the isotope time series and the fit of the isotope data using periodic functions based on significant periodicities.
Contents of the lib folder:
- periodicity_analysis.py: contains the python code used to perform the periodicity analysis of the isotope data.
- utility_functions.py: contains the python code to upload and elaborate the isotope data
Microstructural data of six recent brachiopod species: SEM, EBSD, morphometric and statistical analyses
Full text linkHere, we provide the dataset associated with the research article “Mapping of recent brachiopod microstructure: A tool for environmental studies” [1]. We present original data relative to morphometric and statistical analyses performed on the basic shell structural units (the secondary layer fibres) of brachiopod shells belonging to six extant species adapted to different environmental conditions. Based on SEM micrographs of the secondary layer, fibres from ventral and dorsal valves, and from different shell positions, showing regular and symmetrical cross sectional outlines, were chosen for morphometric measurements using Adobe Photoshop CS6, Image-Pro Plus 6.0 and ImageJ. To work out the reliability of the measurements, the most significant parameters were tested for their probability density by distribution plots; for data visualization and dimension reduction, principal component analysis (PCA) was performed using R 3.3.0 [2] and independent-samples t-tests were performed using SPSS Statistics (IBM Version 22.0. Armonk, NY). Besides a quantitative analysis, a qualitative description of the shell microstructure is provided by detailed SEM imaging and EBSD measurements
Conservation paleobiology of the Montalbano Jonico succession (southern Italy): A Standard Auxiliary Boundary Stratotype (SABS) for the Middle Pleistocene of the Quaternary System
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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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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