1,720,983 research outputs found
From conservation to dissemination: creating digital palaeontological collections at a Department of Earth Sciences and a major Natural History Museum (University of Pisa)
No full textAs many other geological departments worldwide, the Department of Earth Sciences of the
University of Pisa (=Dipartimento di Scienze della Terra dell’Università di Pisa; DSTUP) is home to
a palaeontological teaching collection. Although the specimens that comprise this collection have
no special museological relevance, their role in educating generations of students in natural and
geological sciences is invaluable. The need for creating a digital version of the DSTUP collection was
first felt strongly in 2020, when the COVID-19 pandemics caused all teaching activities to move
online.
Another large, diverse, scientifically priceless palaeontological collection is housed in the Natural
History Museum of the University of Pisa (=Museo di Storia Naturale dell’Università di Pisa;
MSNUP). Highlights of this collection, which includes many holotypes, historical finds and otherwise
unique specimens, are the Permo-Carboniferous flora, the Triassic vertebrate footprints and the
Pleistocene terrestrial mammals from the Monti Pisani massif (Northern Apennines) as well as the
marine mammals and fishes from the marine Miocene and Pliocene of Tuscany and a huge collection
of ammonoids from central Italy (Apennines). The foremost importance of this collection has long
led us to search for ways to create digital models of its most precious elements as a means of
mitigating the corresponding palaeontological risk.
In the last few years, members of the palaeontological laboratories (PaleoLab) of the University of
Pisa have been using the 3D technologies of ‘virtual palaeontology’ to (1) digitize the most relevant
specimens from both collections, (2) create online archives, and (3) make the resulting models
accessible and shareable with the broadest audience possible through social media profiles and
internet browsers. 3D models were produced through structured-light scanning and digital
photogrammetry, and then processed for post-production through the 3D software Blender
whenever necessary. All the 3D scans were then gathered in the online repository Sketchfab, which
was chosen for its user-friendly interface and common usage among museums and teaching
institutions. The DSTUP and MSNUP Sketchfab accounts were linked to social media (Facebook
and Instagram) profiles to promote the dissemination of the corresponding palaeontological
collections. The first results of such an effort are very encouraging in terms of views and online
interactions
The body shape of Perucetus colossus, the extremely heavy basilosaurid from the middle Eocene of Peru
No full textThe basilosaurid cetacean Perucetus colossus, recently described from the middle Eocene (ca. 40-38 Ma) of
the Pisco Basin, Peru, has garnered great attention for its remarkable body mass (Bianucci et al., 2023). The
analysis of its holotype - a partial skeleton comprising 13 vertebrae, 4 ribs, and the right innominate - hints
at a staggering total skeleton mass of ca. 5–8 t, at least twice that of the largest living animal, the blue whale.
This suggests a body mass for Perucetus between 85 and 340 t, making it a contender for the title of the
heaviest animal ever.
Assuming neutral buoyancy, the estimated medial body mass of Perucetus allows its body volume to be
estimated at 180 m3
. Comparison with the 3D body shapes of extant marine mammals, scaled to Perucetus
median length estimate, points to a striking resemblance to the West Indian manatee Trichechus manatus.
This basic analysis reinforces our previous interpretation of Perucetus as a benthic feeder inhabiting
hydrodynamic coastal environments.
Newly discovered ribs from the holotype allowed to reconstruct the maximum cross-section of the ribcage
of Perucetus. The cross-sectional surface area estimated from a 3D model of a double-headed rib from the
central portion of the thorax is approximately 1.4 m2
, notably smaller than our volumetric reconstruction
above. However, it is crucial to note that this area represents only a fraction of the total cross-sectional
surface area of the body. Indeed, in the extant Tursiops truncatus, the ribcage's cross-sectional surface area
at a similar anteroposterior level accounts for only 40% of the entire body's cross-section. Moreover, it is
likely that Perucetus had a greater volume of blubber and muscle tissue around the ribcage compared to the
bottlenose dolphin. Therefore, the use of ribs to reconstruct the body shape of Perucetus requires caution
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
Benthic foraminifera and mollusks from La Maddalena Harbour (Sardinia, Italy): A proxy for recent environmental changes
No full textBenthic foraminifera and mollusks are useful tools for palaeoenvironmental reconstructions due to their ubiquitous presence across marine habitats and their sensitivity to environmental changes induced by natural and anthropogenic events. Their community structures offer valuable insights into habitat characteristics, with certain species acting as bio-indicators of specific environmental conditions. This study delves into the micro- (benthic foraminifera) and macropaleontological (mollusks) analysis of a sediment core drilled from the shallow seabed (maximum depth ∼15 m) in the Ex-military arsenal of the La Maddalena harbour located on the southern coast of La Maddalena island (Sardinia, Italy). In this site, a naval arsenal worked for nearly one century with heavy impact on the coastal zone.
By examining changes in species composition, abundance, and diversity, the research aims to elucidate the environmental history and ecological trajectory of the marine ecosystem in the area. Through the identification of over 90 species of foraminifera and 101 mollusk species, the study reveals a decline in diversity indices with depth, accompanied by shifts in foraminiferal assemblages indicative of different coastal settings. The most frequent foraminiferal species were Elphidium crispum, Ammonia tepida, Planorbulina mediterranensis and Spiroloculina ornata. These results, supported by statistical analyses, allowed identification of distinct assemblages corresponding to varying marine environments. Similarly, mollusk analysis underscores changes in habitat preferences, reflecting a transition from infralittoral vegetated bottoms to more complex substrates, possibly linked to colonization of the area during the last centuries and harbour renovation activities. Collectively, the integration of mollusk and foraminifera data provides a comprehensive understanding of past environmental dynamics, offering valuable insights into the evolution of marine ecosystems in the La Maddalena harbour
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
A new Lower Miocene odontocete assemblage from the Colle della Croce quarry (Feltre; Northeastern Italy), and a chronostratigraphic calibration of the Belluno Sandstone
No full textThe Lower Miocene Libàno Sandstone of Veneto is historically known for being home to abundant
finds of marine vertebrates, especially odontocetes, that have been collected and studied since the
18th century. The historical fossiliferous sites, stretching the Belluno area, expose coarse-grained
sediments that could not be dated by biostratigraphic means as they are barren, and are loosely
constrained to the Early Miocene. Here, we report an odontocete assemblage from the Colle della
Croce quarry, a newly discovered locality near Feltre. The fine-grained sediments exposed in the
quarry have been dated by calcareous nannoplankton biostratigraphy to the 20.89–19 Ma (latest
Aquitanian to early Burdigalian) time interval.
A preliminary systematic assessment of the odontocetes from the new quarry reveals an assemblage
characterized by good diversity and disparity: it includes squalodontids, a new squaloziphiid-like
dolphin, a physeteroid, eurhinodelphinids, an odontocete possibly related to Dalpiazina, and
additional material of basal delphinidans (a cranium with ear bones from this very site was described
as belonging to Kentriodon sp. by Nobile et al., 2024).
Moreover, the marine vertebrate fossils from the Colle della Croce quarry also include sea turtles
(Cheloniidae), bony fishes (Sparidae) and many different elasmobranch taxa.
The new odontocete assemblage from the Colle della Croce quarry is somewhat similar to the
historical Belluno fossil fauna due to the shared occurrence of members of squalodontids,
eurhinodelphinids, physeteroids and possibly dalpiazinids. Apparent idiosyncracies of the Colle della
Croce quarry include the occurrence of a kentriodontid and a squaloziphid-like, whose absence
from the Belluno fauna may be due to small differences in terms of age and palaeoenvironment (with
the strata exposed in the vicinity of Feltre representing distal facies compared to the Belluno
outcrops)
Some updates on the ongoing preparation of a right whale (Mysticeti: Balaenidae) skeleton from the Pliocene of Casenuove (Empoli, Florence Province) at the PaleoLab-UniPi
No full textIn the summer of 1995, an incomplete and largely disarticulated cetacean skeleton was collected in
a clay quarry near Casenuove (Empoli, FI). The finding consists of various cranial bones, the right
mandible, two ribs and other postcranial fragments belonging to a baleen-bearing whale (Cetacea:
Mysticeti) (Bianucci, 1996). Based on various osteological features (e.g., a rounded anterior outline
of the supraoccipital, a ventrolaterally projecting zygomatic process of the squamosal, and a greatly
reduced coronoid process of the mandible), this specimen was provisionally determined as belonging
to the mysticete family Balaenidae, somewhat reminiscent of the genus Eubalaena (Bianucci, 1996).
Nowadays, the Casenuove skeleton is part of the palaeontological collection of the Museo di Storia
Naturale dell’Università di Pisa (MSNUP) with catalogue number MSNUP I-16839 (Bianucci &
Sorbini, 2014). In November 2023, the preparation of this huge skeleton has finally started within
the palaeontological laboratories (PaleoLab) of the University of Pisa. At present, this ongoing effort
has led to liberating the right premaxilla and one rib of MSNUP I-16839 from the entombing
sediment. Characters of both these newly prepared bones confirm the assignment of the Casenuove
whale to the balaenids. Hopefully, the preparation of the remaining skeletal elements will soon allow
for an exhaustive description of this fossil whale as well as for its eventual musealization at the
MSNUP, some thirty years after its discovery
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