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Jardamarekia enigma, a new Early Devonian tryblidioidean from Royal Creek area (Yukon Territory, Canada), and paleobiogeography of the Early Devonian of northwestern Canada
No full textFrýda, Jiří, Blodgett, Robert B., Lenz, Alfred C., Frýdová, Barbora (2011): Jardamarekia enigma, a new Early Devonian tryblidioidean from Royal Creek area (Yukon Territory, Canada), and paleobiogeography of the Early Devonian of northwestern Canada. Zootaxa 2905: 57-62, DOI: 10.5281/zenodo.20686
FIGURE 1. A—Stratigraphic section 1 showing a in Jardamarekia enigma, a new Early Devonian tryblidioidean from Royal Creek area (Yukon Territory, Canada), and paleobiogeography of the Early Devonian of northwestern Canada
No full textFIGURE 1. A—Stratigraphic section 1 showing a distribution of all hitherto described molluscs species from Royal Creek, northern Yukon. B—Generalized maps showing location of section 1 (asterisk) in the Yukon Territory, Canada. Modified from Lenz (1977b).Published as part of Frýda, Jiří, Blodgett, Robert B., Lenz, Alfred C. & Frýdová, Barbora, 2011, Jardamarekia enigma, a new Early Devonian tryblidioidean from Royal Creek area (Yukon Territory, Canada), and paleobiogeography of the Early Devonian of northwestern Canada, pp. 57-62 in Zootaxa 2905 on page 58, DOI: 10.5281/zenodo.20686
FIGURE 2 in Jardamarekia enigma, a new Early Devonian tryblidioidean from Royal Creek area (Yukon Territory, Canada), and paleobiogeography of the Early Devonian of northwestern Canada
No full textFIGURE 2. Jardamarekia enigma sp. nov. from middle Early Devonian (Pragian) age strata of the Road River Formation in the Royal Creek area, Yukon Territory, Canada. The species is from interval 142.0–150.0 m of section 1 (Fig. 1A). Holotype GSC 134793: A–C, F, H–N, shell length 18 mm, width 14 mm, height 10 mm; figure width of shell details: H—11 mm, I—10 mm, J—8 mm, K—3,5 mm, L—10 mm, M, N—3 mm. Paratype: GSC 134794: D–E, G, shell length 26 mm, width 21 mm, height 11 mm.Published as part of Frýda, Jiří, Blodgett, Robert B., Lenz, Alfred C. & Frýdová, Barbora, 2011, Jardamarekia enigma, a new Early Devonian tryblidioidean from Royal Creek area (Yukon Territory, Canada), and paleobiogeography of the Early Devonian of northwestern Canada, pp. 57-62 in Zootaxa 2905 on page 59, DOI: 10.5281/zenodo.20686
Jardamarekia enigma Frýda, Blodgett, Lenz & Frýdová, 2011, sp. nov.
No full textJardamarekia enigma sp. nov. Fig. 2 A–N Holotype. GSC 134793 (Fig. 2 A–C, F, H–N). Paratype. GSC 134794 (Fig. 2 D–E, G). Type locality. Middle Early Devonian (Pragian) age strata of the Road River Formation in the Royal Creek area, Yukon Territory, Canada. It comes from interval 142.0–150.0 m (466–492 feet) of section 1 (Fig. 1), which belongs to the fauna of Pragian age with the brachiopod Davidsoniatrypa johnsoni Lenz, 1968 (Lenz 1977 b). Etymology. enigma —from Latin aenigma (something inexplicable). Diagnosis. Because of monotypic genus, see that of genus. Description. Two well-preserved, silicified, almost complete shells. Shells medium-sized, spoon shaped with distinctly protruding apex; maximum length about 27 mm. Shell as high as wide, twice as long. Aperture elliptical, apertural margin in one plane. Protruding shell apex in middle of shell height, distinctly overhanging anterior margin of aperture (Fig. 2 C–E). Outer shell surface ornamented by strong concentric lamellae, comarginal with aperture. Lamellae crossed by radial threads. Comarginal lamellae, radial threads regularly spaced, forming distinct reticular shell ornamentation at their intersections (Fig. 2 A–C, J, K). Distance between lamellae about twice distance between radial threads. Because of more rapid shell growth in dorsal part of shell, distance between comarginal lamellae in dorsal region higher than in anterior region below shell apex. Lamellae adapically bent, height equals to their distance of separation. Width of each lamella about half of its height (Fig. 2 M–N). Shell apex blunt, cap-shaped without traces of spiral coiling (Fig. 2 C, H–I). Shell thickness about equal to width of comarginal lamellae (Fig. 2 N).Published as part of Frýda, Jiří, Blodgett, Robert B., Lenz, Alfred C. & Frýdová, Barbora, 2011, Jardamarekia enigma, a new Early Devonian tryblidioidean from Royal Creek area (Yukon Territory, Canada), and paleobiogeography of the Early Devonian of northwestern Canada, pp. 57-62 in Zootaxa 2905 on page 60, DOI: 10.5281/zenodo.20686
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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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