1,721,059 research outputs found
Putting the dead to work: A new method to assess the autochthony of marine Ostracoda death assemblages
Full text linkSedimentary and paleontological records can be powerful means of reconstructing ecological and physical environmental changes, by using a variety of records extending proxies to extend chronologies beyond the reach of instrumental or manual records. Ostracods are often used as paleoenvironmental proxies. Estimating the population age structure could be a useful tool for assessing the influence of some environmental parameters on death assemblages and for determining the autochthoneity or allochthoneity of the species that make up the thanatocoenosis. In the literature, several methods based on population age structure have been proposed to distinguish autochthonous and allochthonous components of life/death ostracod assemblages.
The Adult:Juveniles ratio analysis of a rich and well-preserved ostracod assemblage from one site in the circalittoral zone of Pontine Archipelago, in the central-eastern Tyrrhenian Sea, is presented. The new Specific Population Stage Index (SPS) is proposed, built upon the measurements of all growth stages in the assemblage. The population structure using the new SPS Index on three different grain sizes is tested against a list of putative in situ and transported ostracod specimens. The analysis on the small grain size (maximum heigth >63 μm) proved the most effective in describing the putative life ostracod assemblage, whereas in the largest grain size (maximum height >180 μm) the young instars of the smaller species are under-represented. This includes species generally under-represented in the fossil record of the Mediterranean, probably due to sample processing bias and not to the rarity of the species itself. Assessing the autochthoneity of modern/fossil assemblages has great potential for acquiring baseline information on ecosystems before the onset of human activities, making this an extremely powerful approach essential to evaluating anthropogenic impacts. This approach seeks to identify the in situ life assemblages within an ostracod population to ensure that paleoenvironmental interpretations are not biased by transported allochthonous elements
Mixtacandona laisi Klie 1938
No full textMixtacandona laisi Klie, 1938 (Fig. 8 A, B) 1938a Mixtacandona laisi n. sp. Klie: 24–28, figs 33–41. 1938b Candona stammeri n. sp. Klie: 148–150, figs 3–5. 1963 Candona laisi vindobonensis n. ssp. Löffler: 204–205, plate 2. 2000 Mixtacandona laisi (Klie, 1938) —Meisch, 203–204, fig. 86. Well, Diolo di Soragna, Parma. Coordinates: 44°57’45”N 10°08’53”E. Elevation: 38 m a.s.l. Collected on July 0 8, 2009 by Fabio Zanichelli Material examined. GR.559 1 adult ♂, LV partly damaged (Fig. 5 A, B). RV: L = 761 µm, H = 417 µm (Fig. 8 A, B). No other specimens of this species were found. Distribution. Known from Germany, France, Austria, Croatia (Meisch 2000), Slovenia (Mori & Meisch 2012), Italy (this paper).Published as part of Mazzini, Ilaria, Marrone, Federico, Arculeo, Marco & Rossetti, Giampaolo, 2017, Revision of Recent and fossil Mixtacandona Klie 1938 (Ostracoda, Candonidae) from Italy, with description of a new species, pp. 323-340 in Zootaxa 4221 (3) on page 335, DOI: 10.5281/zenodo.25027
Mixtacandona Klie 1938
No full textGenus Mixtacandona Klie, 1938 Diagnosis of the genus (after Danielopol & Cvetkov 1979; Meisch 2000; Karanovic & Pesce 2000, Karanovic 2012): carapace 0.50–0.80 mm long, W 0.7 mm) whereas the species belonging to the riongessa group have a triangular outline and a small size (maximum length <0.7mm). In addition, almost all species belonging to the above-mentioned species groups have greater valve lengths (± 0.56 mm). In particular, M. peliaca (Schäfer, 1945) is slightly longer (0.52 mm) with straight dorsal and ventral margins. M. pseudocrenulata (Schäfer, 1945) (length = 0.54 mm) exhibits a more elongated outline and a symmetrical curved dorsal margin (see also Fig. 10 I in Danielopol 1980b). M. transleithanica (Löffler, 1960) (length = 0.55 mm) displays a rounded dorsal margin and a straight ventral margin. Mixtacandona idrisi n. sp. can be also differentiated by the combination of chaetotaxic character details reported above. Distribution. The species is known from its type locality only.Published as part of Mazzini, Ilaria, Marrone, Federico, Arculeo, Marco & Rossetti, Giampaolo, 2017, Revision of Recent and fossil Mixtacandona Klie 1938 (Ostracoda, Candonidae) from Italy, with description of a new species, pp. 323-340 in Zootaxa 4221 (3) on pages 328-335, DOI: 10.5281/zenodo.25027
NATURAL VERSUS HUMAN FORCING DURING THE LAST THREE MILLENNIA: THE POLLEN EVIDENCE FROM THE TIBER DELTA PLAIN (ROME, ITALY)
No full textNeurocranial anatomy of Sus arvernensis (Suidae, Mammalia) from Collepardo (Early Villafranchian; central Italy). Taxonomic and biochronological implications
No full textSuidae remains recovered from the late Pliocene site of Collepardo (Latium, central Italy) are described and
assigned to Sus arvernensis, a small-sized Ruscinian to Early Villafranchian (MN14-MN16a) species. In Italy,
S. arvernensis only occurs in the Triversa Faunal Unit (MN16a), supporting the recently revised chronology of
Collepardo. CT-scan methods are used to virtually extract and analyse a newly discovered neurocranium,
providing the content for the first inner cranial description carried out on an extinct Suidae. Our analysis
reveals that S. arvernensis has an anteroposteriorly elongated and dorsoventrally flat cerebrum, similar to
that of the Asian Babyrousa babyrussa and the African Hylochoerus meinertzhageni. These species substantially
differ in size and are representatives of two widely diverging phylogenetic clades, excluding relatively
simple evolutionary or allometric explanations for brain morphology in Suidae
Rediscovering Lutra lutra from Grotta Romanelli (southern Italy) in the framework of the puzzling evolutionary history of Eurasian otter
Full text linkA river otter hemimandible has been rediscovered during the revision of the historical collections of G.A. Blanc from Grotta
Romanelli, complementing the ongoing multidisciplinary research fieldwork on the site. The specimen, recovered from the
level G (“terre rosse”; early Late Pleistocene or late Middle Pleistocene), is here assigned to Lutra lutra. Indeed, morphological
and morphometric comparisons with other Quaternary Lutrinae fossils from Europe allow to exclude an attribution
to the relatively widespread and older Lutra simplicidens, characterized by distinctive carnassial proportions. Differences
with Cyrnaonyx antiqua, which possessed a more robust, shellfish-feeding dentition, support the view of a successful niche
repartition between the two species during the late Middle to Late Pleistocene of Europe. The occurrence of Lutra lutra from
the “terre rosse” of Grotta Romanelli suggests deep modifications of the landscapes due to the ecological adaptation of the
taxon, and indicates that the Eurasian otter spread into Europe at the Middle–Late Pleistocene transition
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
Mixtacandona thessalica, a new species of ostracod (Crustacea, Ostracoda) from a sulfidic cave in central Greece
Full text linkThe genus Mixtacandona Klie, 1938 (Crustacea, Ostracoda, Candonidae) includes 21 living non-marine species, all subterranean, with Palearctic distribution. Here we report on Mixtacandona thessalica sp. nov., collected in a sulfidic cave in central Greece. It can be considered an extremophile species because of its ability to thrive in an environment with high concentrations of sulfide and reduced chemical compounds. Mixtacandona thessalica sp. nov. belongs to the species group laisi–chappuisi, one of the five groups in which species of the genus are conventionally placed. A detailed morphological description of the valves and the soft parts of the new species is offered. In addition, COI and 28S genetic markers were sequenced. Mixtacandona thessalica sp. nov. is easily distinguishable from the other species in the genus by its peculiar carapace outline and the marked sexual dimorphism of the posterior margin of valves, as well as by details of chaetotactic characters. The discovery of Mixtacandona thessalica sp. nov. increases the number of non-marine ostracod species known from Greece, which is still rather scarce compared to other Mediterranean countries due to the scarcity of studies. Ten hypogeal species of living ostracods have already been reported from Greece, six of which are considered endemic, and among them three belong to the genus Mixtacandona. It is stressed that a comprehensive review of this genus by combining a thorough morphological approach and molecular techniques, is most needed to assess its phylogenetic relationships within the family Candonidae
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
- …
