370 research outputs found
Protocol for the reconstruction of micromammals from fossils. Two case studies: The skulls of Beremendia fissidens and Dolinasorex glyphodon
We have developed a protocol for reconstructing 3D models of the skulls of extinct species of small mammals. For the first time, the reconstruction uses fragments of fossils from a mixture of different specimens and from related extant species. We use free software and commercial computers to make the process reproducible and usable for the scientific community. We present a semi-quantitative protocol to face the problem of making 3D reconstructions of fossil species that are incomplete in the fossil record and/or represented by a mixture of different individuals, as usually occurs with small vertebrates. Therefore this approach is useful when no complete skull is available. The protocol combines the use of microCT scan technology with a subsequent computer treatment using different software tools for 3D reconstruction from microCT and 3D design and printing (e.g. Fiji, SPIERS, Meshlab, Meshmixer) in a defined order. This kind of free and relatively simple software, plus the detailed description, makes this protocol practicable for researchers who do not necessarily have great deal of experience in working with 3D. As an example, we have performed virtual reconstructions of the skulls of two species of insectivore small mammals (Eulipotyphla): Beremendia fissidens and Dolinasorex glyphodon. The resulting skulls, plus models of the extant shrews Blarina brevicauda, Neomys fodiens, Crocidura russula and Sorex coronatus, make it possible to compare characteristics that can only be observed by means of microCT 3D reconstructions, and given the characteristics of the material, using this protocol. Among the characters we can compare are the position of the mandibles, the spatial relations among all the teeth, the shape of the snout and, in general, all parameters related with the anatomy of the rostrum. Moreover, these reconstructions can be used in different types of context: for anatomical purposes, especially to see internal features or characteristics at whole-skull scale, for bioengineering, animation, or other techniques that need a digital model
The Mark of the Beast: a bone assemblage assessment from the North of the Iberian Peninsula (MIS 3)
The cave of Abauntz (Navarra, Spain) has had a consistent record of human presence since 50,000 years ago. In this paper, we present the results of the taphonomy and taxonomy analyses made on an assemblage composed of over 3,000 bones found in the unit h of the cave of Abauntz, the earliest level in the cave's stratigraphy with human presence and dated in the MIS 3. Taxonomy assessment described 14 mammal taxa, identified 2,426 remains, and quantified 33 individuals, showing a greater abundance of cave bears (Ursus spelaeus) over any other taxa. The Taphonomic study assessed the skeletal survival ratio, the assemblage spatial distribution, the skeletal elements' breakage pattern, and the toothmarks on the remains. Altogether, the combined results of the analyses allowed inferring that carnivores were the main accumulator agents over human activity. An occupation pattern of the cave is proposed here, with Ursus spelaeus using the cavity during winter as a shelter for hibernation. In contrast, carnivores used it in other seasons mainly for feeding. At some point during MIS 3, neanderthals used it briefly, leaving behind a lithic tools’ assemblage. The results were compared to the faunal assemblages described in younger levels inside the cave, showing a severe decrease in the carnivore’s variety and abundance
A cave occupied by cave bears for thousands of years in the Sobrarbe-Pirineos UNESCO Global Geopark (Huesca, Aragon, Spain)
The Sobrarbe-Pirineos UNESCO Global Geopark shows an extremely well-developed underground karst relief as a result of the great abundance and thickness of its limestone formations. The most important Pleistocene vertebrate site within the Geopark is Coro Tracito Cave at Tella. The fossil association is made up exclusively of bones belonging to Ursus spelaeus from the upper Pleistocene, accumulated over several thousand years. Based on scientific analysis of the fossil bones, an interesting public outreach project has been organized, involving the refurbishment of the site within the cave and the creation of a permanent exhibition called the Tella Cave Bear Museum. These two infrastructures are visited by thousands of tourists each year and constitute the main geoscientific tourist attraction of the Sobrarbe-Pirineos Geopark
Avian eggshell remains in the human bearing level TD6 of the Gran Dolina site (Early Pleistocene, Atapuerca, Spain)
The site of Gran Dolina (Atapuerca, Spain) has a 19-metre-thick Lower and Middle Pleistocene infilling, divided into eleven levels. This work is focused on the level TD6 (0.8–0.9Ma), consisting of a succession of debris flow and fluvial facies with a high diversity of vertebrates, including Homo antecessor. Here we describe for first time eggshell fragments from Atapuerca, recovered by screen washing of sediments from the excavations. The 22 eggshell fragments recovered are small and poorly preserved, with all material showing signs of abrasion. All eggshells have smooth outer surfaces, densely packed mammillae, and are multi-layered. Thus, they can be identified as avian eggshells. Most fragments were relatively well intact, with no signs of recrystallisation, as evidenced by cathodoluminescence analysis, however the degree of abrasion of the fragments hindered the identification of some ultrastructural characters. Three taxa have been identified: Charadriiformes, Gruidae and Anseriformes (all recorded in the TD6 assemblage by osteological remains). The association supports the presence of water bodies close to the site. The relatively high diversity of ootaxa in the small sample size analysed suggest that a wide range of the nesting species inhabited surrounding areas of Gran Dolina at the moment of accumulation of the TD6 level
Crop classification based on temporal signatures of Sentinel-1 observations over Navarre province, Spain
Crop classification provides relevant information for crop management, food security assurance and agricultural policy design. The availability of Sentinel-1 image time series, with a very short revisit time and high spatial resolution, has great potential for crop classification in regions with pervasive cloud cover. Dense image time series enable the implementation of supervised crop classification schemes based on the comparison of the time series of the element to classify with the temporal signatures of the considered crops. The main objective of this study is to investigate the performance of a supervised crop classification approach based on crop temporal signatures obtained from Sentinel-1 time series in a challenging case study with a large number of crops and a high heterogeneity in terms of agro-climatic conditions and field sizes. The case study considered a large dataset on the Spanish province of Navarre in the framework of the verification of Common Agricultural Policy (CAP) subsidies. Navarre presents a large agro-climatic diversity with persistent cloud cover areas, and therefore, the technique was implemented both at the provincial and regional scale. In total, 14 crop classes were considered, including different winter crops, summer crops, permanent crops and fallow. Classification results varied depending on the set of input features considered, obtaining Overall Accuracies higher than 70% when the three (VH, VV and VH/VV) channels were used as the input. Crops exhibiting singularities in their temporal signatures were more easily identified, with barley, rice, corn and wheat achieving F1-scores above 75%. The size of fields severely affected classification performance, with ~14% better classification performance for larger fields (>1 ha) in comparison to smaller fields (<0.5 ha). Results improved when agro-climatic diversity was taken into account through regional stratification. It was observed that regions with a higher diversity of crop types, management techniques and a larger proportion of fallow fields obtained lower accuracies. The approach is simple and can be easily implemented operationally to aid CAP inspection procedures or for other purposes. © 2020 by the authors.This work was supported by the Spanish Ministry of Economy and Competitiveness and the European Regional Development Fund (MINECO/FEDER-UE) through a project (CGL2016-75217-R) and a grant (BES-2017-080560). It was also partly founded by project PyrenEOS EFA 048/15, that has been 65% cofinanced by the European Regional Development Fund (ERDF) through the Interreg V-A Spain-France-Andorra programme (POCTEFA 2014-2020)
Les fossiles de Castor fiber de gruta da Aroeira (Portugal) et l’intéraction entre humains et castors
Here we analyze the fossil remains of Castor fiber from the Middle Pleistocene site of Gruta da Aroeira, in the Almonda karst system, Tagus basin (Torres Novas, Portugal) and discuss the archaeological implications of the presence of beavers in the region. The Almonda karst system has been the backdrop for human evolution in Portugal, because there are different localities, of different ages, from the Middle Pleistocene to the Holocene, with fossil remains of hominins as well as faunal and archaeological remains. Beaver fossils have been found in the archaeological deposits of at least three cavities of the karst system: the Gruta da Aroeira, the Gruta da Oliveira and the Galeria da Cisterna. Here, for the first time, we describe the fossils of Castor fiber from Gruta da Aroeira. The beavers from Aroeira are remarkable because they are the westernmost fossil record of Castor fiber in Europe dated to Marine Isotope Stage (MIS) 11, around 420 ka. The aim of the present article is twofold, firstly to study the fossils of beavers from the Aroeira locality, and secondly to discuss the palaeoecological and palaeoenvironmental implications of the presence of this rodent in the Almonda karst sites. This allows us to discuss the hominin-beaver interactions.Ici, nous analysons les fossiles de Castor fiber du site Pléistocène moyen de Gruta da Aroeira, dans le système karstique de Almonda, bassin du Tage (Torres Novas, Portugal), et les implications archéologiques de la présence de castors dans la région. Le karst d'Almonda est un cadre de référence pour l’étude de l'évolution humaine dans la partie occidentale de l'Europe, du Pléistocène moyen à l'Holocène, avec aussi bien des restes d’hominidés fossiles, que de faunes et de vestiges archéologiques. Des fossiles de castors ont été trouvés dans les gisements archéologiques d'au moins trois cavités du système karstique : la Gruta da Aroeira, la Gruta da Oliveira et la Galeria da Cisterna. Ici, pour la première fois, nous décrivons les fossiles de Castor fiber de Gruta da Aroeira. Les castors d'Aroeira sont remarquables car ils sont la trace fossile la plus occidentale de Castor fiber en Europe; ils sont datés du Stade Isotopique Marin (MIS) 11, autour de 420 ka. Le but de cet article est double, d'une part de présenter l'évolution des castors à travers les fossiles d'Aroeira, et d'autre part de discuter des implications paléoécologiques et paléoenvironnementales de la présence de ce rongeur dans le karst d’Almonda. Cela nous permet de discuter des possibles interactions entre humains et castors.info:eu-repo/semantics/publishedVersio
Catálogo de los micromamíferos (Rodentia, Eulipotyphla, Chiroptera) del Cuaternario Superior Ibérico del Museu de Geologia de Barcelona, Spain
The present catalogue represents an attempt to list Middle–Upper Pleistocene and Holocene micromammal material deposited in the Museu de Geologia de Barcelona, coming from 12 Iberian Peninsula localities (ten from Catalonia, one from Castilla y León and one from Andalucia). It permits to observe changes in species geographical distribution as Iberomys cabrerae, Microtus oeconomus, Hystrix cristata or Citellus sp. with regard to their present location. By this way, we can observe the existence during the Middle–Upper Pleistocene of some today extinct species such as Pliomys lenki or Allocricetus bursae.
Key words: Middle-Upper Pleistocene, Holocene, Micromammals, Palaeobiogeography, Museo de Geologia de Barcelona, Spain.En este trabajo se presenta una lista del material de micromamíferos del Pleistoceno Medio-Superior y Holoceno depositado en el Museo de Geología de Barcelona, perteneciente a 12 yacimientos de la Península Ibérica (diez de Cataluña, uno de Castilla y León y uno de Andalucía). Este listado nos permite observar cambios en la distribución de especies como Iberomys cabrerae, Microtus oeconomus, Hystrix cristata o Citellus sp. respecto a su actual situación geográfica. Así mismo, nos permite vislumbrar la existencia durante el Pleistoceno Medio–Superior de algunas especies actualmente extintas, como Pliomys lenki y Allocricetus bursae.
Palabras clave: Pleistoceno Medio-Superior, Holoceno, Micromamíferos, Paleobiogeografía, Museu de Geologia de Barcelona, España
Birds from sima del elefante, atapuerca, spain: Palaeoecological implications in the oldest human bearing levels of the iberian peninsula
Palaeoenvironmental reconstruction of Early Pleistocene sites has a particular interest as it sheds light on how the arriving of the first Europeans occurred, as well as on the nature of the relation between these humans and the ecosystems. Bird remains are useful tools for this purpose, because they are commonly represented in the assemblages and most taxa still exist, allowing a direct comparison between past and extant birds associations. Here we analyse the bird remains from the Early Pleistocene levels of the Sima del Elefante site (1.1 to 1.5 million years old). Almost 10.000 remains belonging to at least 26 different taxa have been included. The assemblage is dominated by corvids and has a mixed origin, with cave-dwelling taxa dying in the cave and other taxa being accumulated by predators. The Sima del Elefante avian assemblage provides the oldest record of several taxa in the Iberian Peninsula (Haliaeetus albicilla, Corvus pliocaenus). Besides, here we report the oldest evidence of Imperial Eagle in the Iberian Peninsula, prior to the separation of the oriental and Iberian populations. The assemblage composition suggests that open environmental conditions were dominant, with minor presence of woodlands and water bodies, which is congruent with some previous approaches by other proxies. The first humans occupying the Iberian Peninsula inhabited under Mediterranean climate conditions, which gradually deteriorated, as reflected by the avian turnover recorded at the middle Pleistocene Atapuerca assemblages. © 2021 Universita degli Studi di Milano. All rights reserved
Lingual nerve injury after third molar removal: Unilateral atrophy of fungiform papillae
Background: Pain and sensory changes due to lingual nerve injury are one of the most common alterations that
follow surgical removal of third molar. They are usually transient but other less common complications, such as the
atrophy of fungiform papillae, have an uncertain prognosis.
Case Description: We report a case of a 34-year-old woman who presented a unilateral lingual atrophy of fungiform
papillae after third molar extraction accompanied by severe dysesthesia that altered her daily life significantly during
the following months and how this complication evolved over time. We conducted a literature review on the
different factors that can lead to a lingual nerve injury.
Clinical Implications: The clinical evolution of temporary and permanent somatosensitve injuries is an important
fact to take into consideration during the postoperative management because it will indicate the lesion prognosis
- …