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A late occurring “Hipparion” from the middle Villafranchian of Montopoli, Italy (Early Pleistocene; MN16b; ca. 2.5 Ma)
Get PDFWe report here for the first time the occurrence in the Montopoli large mammal fossil assemblage of a small equid taxon identified as “Hipparion” sp., associated to the monodactyl large horse Equus cf. livenzovensis. This occurrence has been recognised on a specimen that the late De Giuli (1938-1988) identified as Hipparion sp. in unpublished notes available in the archives of the Vertebrate Palaeontology Laboratory of the Dipartimento di Scienze della Terra at the Università degli Studi di Firenze. Although fragmentary, the specimen documents the occurrence of “Hipparion” at the middle Villafranchian (early Pleistocene, ca. 2.5 Ma) site of Montopoli, one of the latest occurrences of an hipparionine horse in western Europe. The western Eurasian “Hipparion” evolutionary history is summarised herein
The Villafranchian perissodactyls of Italy: knowledge of the fossil record and future research perspectives
No full textThe Villafranchian fossil record of Perissodactyla is of a great interest because the appearance of the genus Equus and disappearance of the genus Tapirus mark important faunal turnovers. Here, we provide new data on Italian Villafranchian Tapiridae, Rhinocerotidae, and Equidae with updates from the last comprehensive review; most relevant are those of the Rhinocerotidae and Equidae. At present only two Villafranchian rhinoceros’ species are documented in Italy: Stephanorhinus jeanvireti and Stephanorhinus etruscus. The two species can be distinguished by several morphological features and by the dimensions of their bones. Stephanorhinus etruscus occurred throughout the Villafranchian; despite the numerous records, its remains are not enough to investigate morphometric trends. The Equidae include seven species including new occurrences of Hipparionine horses and of the genus Equus. The statistical analyses performed on the Equus species show two different evolutionary trends, namely the stenonine lineage “Equus livenzovensis - Equus stenonis” and the small-to-medium-sized lineage “Equus senenzensis - Equus stehlini”, suggesting a different evolution of these species. Moreover, the analyses show close relationships between the Italian Equus stenonis samples and three European Equus stenonis subspecies (E. stenonis vireti, E. stenonis guthi, and E. stenonis pueblensis). We begin to reconsider the validity of E. stenonis subspecies identification in order to provide new perspectives on the taxonomy of this species
Equus stenonis (Equidae, mammalia) from the early pleistocene of pantalla (italy) and the dispersion of stenonine horses in europe
No full textStenonine horses roamed across Eurasia for a long-time interval between the Early Pleistocene and the early Middle Pleistocene. These forms probably derived from North American Equus simplicidens and recent research suggests that they can be at the basis of the radiation of the extant African zebras. Equus stenonis is the most widespread stenonine horse in the Early Pleistocene of Europe. Here we describe the Equus record from Pantalla (Italy) and we refer it to E. stenonis based on a combination of morphometric analyses of metapodials and tibia. In particular, our comparisons show remarkable similarities between the Pantalla horse and E. stenonis from Saint Vallier (France). The studied sample allows suggesting an age close to the beginning of the late Villafranchian (~2 Ma) for the Pantalla assemblage, thus representing one of the earliest records of E. stenonis in Italy. Furthermore, our analyses highlight a substantial morphometric homogeneity in European E. stenonis samples, supporting that they may represent intraspecific variation of a single long-lasting widespread species
Equus cf. Livenzovensis from montopoli, Italy (early pleistocene; mn16b; ca. 2.6 ma)
Get PDFWe report here the occurrence and metric characteristics of a large species of Equus from Montopoli (Tuscany, Italy) correlated with the middle Villafranchian, 2.6 Ma (early Pleistocene). This species co-occurs with a rare “Hipparion” sp. at Montopoli. We compare the Montopoli Equus cf. livenzovensis with a large suite of extant Equus including zebras, asses and a large suite of fossil Equus using bivariate and log10 ratio analyses of anterior and posterior 1 st phalanges III. Our comparisons show that Montopoli anterior and posterior 1 st phalanges III are larger than in living zebras and asses and comparable in size and proportions to the early Pleistocene large Chinese species Equus eisenmannae and late Pleistocene Rancho La Brean Equus occidentale. Equus livenzovensis was a larger species than Equus stenonis and Equus stehlini. Equus cf. livenzovensis is not represented as far as we know by skulls and dentitions in the Italian Villafranchian record
An updated review on Equus stenonis (Mammalia, Perissodactyla): New implications for the European early Pleistocene Equus taxonomy and paleoecology, and remarks on the Old World Equus evolution
No full textEquus stenonis is one of the most iconic fossil species of the Early Pleistocene. Although it is known from the 19th century, its taxonomic and evolutionary position has been extensively debated among equid specialists, including multiple interpretations. The current work aims to review the European E. stenonis record, by morphological, morphometrical and statistical analyses combined with body mass and net primary production estimates. Furthermore, we investigate the evolution of E. stenonis cranial anatomy in comparison with the Plio-Pleistocene species from North America, Eurasia and Africa, and extant zebras and asses. Our review of European E. stenonis samples has closely considered the E. stenonis subspecies Equus stenonis vireti, Equus stenonis guthi, Equus stenonis pueblensis, Equus stenonis olivolanus and Equus stenonis stenonis which we recognize as being ecomorphotypes of Equus stenonis, with the exception of Equus stenonis senezensis and Equus stenonis mygdoniensis. These two last subspecies warrant the species ranks of Equus senezensis and Equus altidens, respectively. This has led us to propose a new revised biochronology of European Early Pleistocene Equus. Our evolutionary interpretations based on cranial morphology reveals that the evolutionary lineage of extant zebras can be recognized in deep time from the North American species Equus simplicidens, through the European E. stenonis and the African Equus koobiforensis. European stenonine horses likewise represent the original source for the African Pleistocene fossil species and extant Equus grevyi
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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