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Evolutionary patterns of cat-like carnivorans unveils drivers of the sabertoothed morphology
Get PDFpeer reviewedThe sabertooth morphology stands as a classic case of convergence, manifesting recurrently across various vertebrate groups, prominently within two carnivorans clades: felids and nimravids. Nonetheless, the evolutionary mechanisms driving these recurring phenotypes remain insufficiently understood, lacking a robust phylogenetic and spatiotemporal framework. We reconstruct into the tempo and mode of cranio-mandibular evolution of Felidae and Nimravidae and evaluate the strength of the dichotomy between conical and sabertoothed species but also within sabertoothed morphotypes. To do so, we investigate morphological variation, convergence, phenotypic integration, and evolutionary rates, employing a comprehensive dataset of nearly 200 3D models encompassing mandibles and crania from both extinct and extant feline-like carnivorans, spanning their entire evolutionary timeline. Our results reject the hypothesis of a distinctive sabretooth morphology, revealing instead a continuous spectrum of feline-like phenotypes in both cranium and mandible, with sporadic instances of unequivocal convergence. Disparity peaked at the end of the Miocene and is usually higher in clades containing taxa with extreme sabertoothed adaptations. We show that taxa with saberteeth exhibit a lower degree of craniomandibular integration, allowing to exhibit a greater range of phenotypes. Those same groups usually show a burst of morphological evolutionary rate at the beginning of their evolutionary history. Consequently, we propose that a reduced degree of integration coupled with rapid evolutionary rates emerge as key components in the development of a sabertoothed morphology in multiple clades.SYNTHESYS Access Progra
Figure 8 in Anatomy and phylogenetic relationships of Temnodontosaurus zetlandicus (Reptilia: Ichthyosauria)
No full textFigure 8. Photograph of the holotype of 'Ichthyosaurus' acutirostris (NHMUK PV OR 14553). A, the whole specimen. B, interpretation of the skull.Published as part of Laboury, Antoine, Bennion, Rebecca F., Thuy, Ben, Weis, Robert & Fischer, Valentin, 2022, Anatomy and phylogenetic relationships of Temnodontosaurus zetlandicus (Reptilia: Ichthyosauria), pp. 172-194 in Zoological Journal of the Linnean Society 195 on page 186, DOI: 10.1093/zoolinnean/zlab118, http://zenodo.org/record/653678
Figure 6 in Anatomy and phylogenetic relationships of Temnodontosaurus zetlandicus (Reptilia: Ichthyosauria)
No full textFigure 6. Photograph and interpretation of the specimen MNHNL TU885 Temnodontosaurus cf. zetlandicus A, B, palate in ventral view. C, D, Basicranium in posterior view. Abbreviation: ECA, extracondylar area of the basioccipital.Published as part of Laboury, Antoine, Bennion, Rebecca F., Thuy, Ben, Weis, Robert & Fischer, Valentin, 2022, Anatomy and phylogenetic relationships of Temnodontosaurus zetlandicus (Reptilia: Ichthyosauria), pp. 172-194 in Zoological Journal of the Linnean Society 195 on page 183, DOI: 10.1093/zoolinnean/zlab118, http://zenodo.org/record/653678
Figure 2 in Anatomy and phylogenetic relationships of Temnodontosaurus zetlandicus (Reptilia: Ichthyosauria)
No full textFigure 2. Photograph and interpretation of the holotype of Temnodontosaurus zetlandicus comb. nov. (CAMSM J35176). A, B, in left lateral view. C, D, in right lateral view.Published as part of Laboury, Antoine, Bennion, Rebecca F., Thuy, Ben, Weis, Robert & Fischer, Valentin, 2022, Anatomy and phylogenetic relationships of Temnodontosaurus zetlandicus (Reptilia: Ichthyosauria), pp. 172-194 in Zoological Journal of the Linnean Society 195 on page 177, DOI: 10.1093/zoolinnean/zlab118, http://zenodo.org/record/653678
Geosaurus lapparenti
No full text<p> <i> <i>GEOSAURUS</i> LAPPARENTI</i> (DEBELMAS & STRANNOLOUBSKY, 1957)</p> <p> The bones referred to the pelvic girdle of <i>Geosaurus lapparenti</i> in Debelmas (1958) are not included in our work. Indeed, those remains do not correspond to the shape of any element of a metriorhynchoid pelvic girdle.We hypothesize that those elements correspond to either girdle of a plesiosaur.</p>Published as part of <i>Scavezzoni, Isaure, Fischer, Valentin, Johnson, Michela M. & Jouve, Stéphane, 2024, Form and function of the pelvic girdle of Thalattosuchia and Dyrosauridae (Crocodyliformes), pp. 135-326 in Geodiversitas 46 (6)</i> on page 194, DOI: 10.5252/geodiversitas2024v46a6, <a href="http://zenodo.org/record/11106598">http://zenodo.org/record/11106598</a>
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
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