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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Mid-Pleistocene Extinction of Deep-Sea Ostracoda?

Gaiger, Frances Jean January 2006 (has links)
A global extinction event has been documented in protozoan foraminifera in the late Pliocene to Pleistocene. The timing of the extinction event varied depending on location, however for Ocean Drilling Project Site 1125, disappearances occurred between 2.5 and 0.57 Ma, with the major decline approximately 1.1 Ma. In order to determine if this event affected benthic organisms other than protozoans, this study was undertaken to determine how podocopid ostracods (Crustacea) recovered Ocean Drilling Program Site 1125 responded. The present study was hindered by the small number of valves recovered; the fact that a large proportion of taxa found were undescribed and new to science; and the current state of taxonomic scheme that is under significant revision. These factors meant that a comprehensive comparison could not be achieved. Despite this, counts of ostracod valves and assessments of diversity from this study reveal a significant increase in both parameters from approximately 900-600 ka. Three possible causes were investigated to account for this increase, sediment type and sample size; affects of taphonomy, mainly dissolution; or an actual biotic 'event'. Statistical analyses showed that although sample size did have some effect, it was not the sole reason for the increase in ostracod numbers. Dissolution had an expected affect on the percentage of juveniles but no correlations were found with other sample characteristics. Sedimentation rate was investigated but this also proved unrelated. Therefore, it is suggested that the increase in total ostracod valves and diversity which occurs between 900 and 600 ka was in fact a natural, biotic 'event'. This preliminary evidence suggests that an oceanographic event that has negatively impacted on the foraminifers has had the reverse affect on the ostracod assemblage, in the sense that both population size and diversity increase during that time.
132

Commensal or comestible? : the role and exploitation of small, non-ungulate mammals in early European prehistory : towards a methodology for improving identification of human utilisation

Howard, Wendy June January 2013 (has links)
Small mammals, namely those species larger than microfauna like rats and murids but smaller than medium, sheep-size fauna, are generally one of the less studied areas of zooarchaeology. While this may be partly influenced by modern cultural biases, it is more often because finding small, rabbit-sized, mammal remains in archaeological deposits presents a problem in accurately differentiating between those arising from natural, biological and anthropogenic agencies. This thesis tackles this subject using a synthesis of different methods, examining the exploitation and role of small, non-ungulate mammals in early Western European prehistory by combining existing ethnographic knowledge and archaeological research with actualistic experiments and bone assemblage analysis. It first presents a detailed summary of the various taphonomic effects on bone from natural, biological and human action, with particular reference to those of small mammals, using empirical evidence to describe the processes and likely resultant effects. Small mammal utilisation is then contextualised using archaeological and ethnographic evidence to examine past and present practices in Europe and other areas of the world. Different acquisition methods, such as hunting and trapping, are described, and using small mammals for dietary and non-dietary purposes is outlined, along with the rationale for such utilisation given their size. Also considered are other, more abstract ideological and symbolic roles they fulfilled within different cultures, whether physically using parts of the animal, or conceptually. To extend the existing methods available to zooarchaeologists, and improve identifying human exploitation of these species, the ‘chaîne opératoire’ of small game use is examined from an osteological perspective, starting with acquisition, through processing, cooking and consumption to discard, using a series of experiments and microscopic analysis to explore potential bone modification signatures and fracture patterns arising from such activities. Finally, it places these results into broader context by comparing the fracture patterns with bones from British and North American archaeological sites, to demonstrate that similar changes can be seen.
133

Hyénidés modernes et fossiles d'Europe et d'Afrique : taphonomie comparée de leurs assemblages osseux / Modern and fossil hyenids from Europe and Africa : a comparative taphonomic study of their bone assemblages

Fourvel, Jean-Baptiste 13 December 2012 (has links)
En raison de sa présence récurrente dans les ensembles paléontologiques d’Europe au Pléistocène, l’hyène des cavernes (Crocuta crocuta spelaea GOLDFUSS) est un carnivore particulièrement étudié en taphonomie. Depuis le XIXème siècle, la reconnaissance du rôle joué par les grands prédateurs, et plus particulièrement de l’hyène, dans la formation des assemblages osseux, a permis de dégager les grandes tendances écologiques et évolutives de ces carnivores (habitat en grotte, consommation osseuse, chasse vs. charognage, compétition interspécifique, interaction Homme-Carnivores). L’éthologie de l’hyène tachetée fossile (accumulateur d’ossements, ostéophagie) repose largement sur le développement des travaux écologiques et néo-taphonomiques depuis les années 1970. Le présent travail porte sur un bilan paléontologique et taphonomique des hyénidés modernes et Pléistocènes. Une première partie est consacrée à la présentation synthétique des 3 principaux genres (Crocuta, Hyaena, Parahyaena) et concerne leur systématique, biogéographie et ostéométrie. Ce dernier point permet de confirmer d’une part les fluctuations de masse corporelle des hyènes en relation avec les changements climatiques au cours du Pléistocène et d’autre part la difficulté à évaluer le dimorphisme sexuel à partir des éléments squelettiques crâniens et postcrâniens. Une seconde partie porte sur l’étude de 14 échantillons osseux modernes et fossiles produits par les hyénidés. Six accumulations en contexte de repaires et 3 ensembles de plein-air composent les séries modernes. Elles représentent des contextes écologiques et géographiques distincts (Djibouti et Afrique du Sud) et sont rapportées aux trois espèces d’hyènes (repaires : Crocuta : Dumali (NR Ongulés = 421), Heraide (NR Ongulés = 216), Yangula Ari (NR Ongulés = 133), Oboley (NR Ongulés = 259) ; Hyaena : Datagabou (NR Ongulés = 352) ; Parahyaena : Uniab (NR Ongulés = 568) ; kill-sites de Crocuta : Ali Daba : NR Ongulés = 40 ; Dumali : NR Ongulés = 185 ; Heraide : NR Ongulés = 460). L’analyse taphonomique de ces assemblages permet de caractériser les modifications produites par les hyénidés modernes. Ce modèle est ensuite pris en compte dans l’étude de 5 repaires d’hyène tachetée fossile inédits : Artenac c10 (OIS5c ; NRDT = 1301), Peyre (OIS5e ; NRDT = 2815), Grand Abri aux Puces Réseau Supérieur (100ka ; NRDT = 2360), Fouvent (OIS3 ; NRDT = 3347) et Conives (OIS3 ; NRDT = 1717). Afin de caractériser objectivement la signature taphonomique des hyènes fossiles, deux autres séries, plus anciennes (Pléistocène moyen), ont été brièvement prises en considération (Ceyssaguet (Pachycrocuta brevirostris) et Lunel-Viel 1 (Crocuta spelaea intermedia)) ainsi que deux échantillons osseux produits par d’autres grands Carnivores (le jaguar européen (Panthera onca gombaszoegensis) d’Artenac I et II et le loup (Canis lupus) moderne de Pologne). Les analyses comparées d’ensembles osseux créés par les Hyénidés, Félidés et grands Canidés permettent de reconsidérer les critères de caractérisation couramment utilisés en Taphonomie archéologique. Il apparait que les Carnivores partagent des caractéristiques taphonomiques communes (morphométrie des traces de dents, morphotypes de consommation, distribution squelettique des proies), peu favorables à l’identification spécifique ou/et générique des Carnivores ayant consommés des restes osseux. Le comportement ostéophagique de l’hyène (fossile) se distingue de celui des autres grands prédateurs par : une importante production des éclats diaphysaires d’os longs, la présence récurrente de coprolithes et enfin un nombre élevé d’os et/ou d’éclats ingérés. Parmi ces derniers, le spectre anatomique des éléments régurgités d’une part ainsi que leur degré de dissolution important d’autre part caractérisent significativement les séries paléontologiques produites volontairement par les hyènes. Ces critères pourraient constituer les éléments de diagnose taphonomique les plus intéressants. / (Crocuta crocuta spelaea GOLDFUSS) is a carnivore particularly studied in taphonomy. For the XIXth century, the recognition of the role played by large predators, and more particularly the (cave) hyena, in bone assemblage formation, allowed to precise main ecological and evolutionary trends of these carnivores (cave occupation, consumption of bones, predation vs scavenging, interspecific competition, Humans-Carnivores interaction). The behavior of the fossil spotted hyena (accumulator of bones, osteophagy) is mainly based on the development of the ecological and neotaphonomic works since the 1970s. The present work concerns a paleontological and taphonomic survey of Modern and Pleistocene Hyenids. A first part is dedicated to the synthetic presentation of the 3 main genera (Crocuta, Hyaena, Parahyaena) concerning their systematics, biogeography and osteometrics. This last point, particularly developed, allows to confirm on one hand the fluctuations in body mass of hyenas in connection with climate change and on the other hand the difficulty estimating the sexual dimorphism from cranial and postcranial elements. A second part concerns the study of 14 modern and fossil bone samples produced by Hyenids. Modern samples (6 dens and 3 kill-sites) come from different ecological and geographical contexts (Republic of Djibuti, South Africa). Dens are as follows : Crocuta : Dumali (Ungulate NISP = 421), Heraide (Ungulate NISP = 216), Yangula Ari (Ungulate NISP = 133), Oboley (Ungulate NISP = 259) ; Hyaena : Datagabou (Ungulate NISP = 352) ; Parahyaena : Uniab (Ungulate NISP = 568). Kill-sites are as follows : Crocuta : Ali Daba : Ungulate NISP = 40 ; Dumali : Ungulate NISP = 185 ; Heraide : Ungulate NISP = 460). The taphonomic analysis of these bone samples allows to characterize modifications produced by modern Hyenids. This model is then taken into account in the study of 5 unpublished fossil spotted hyena dens of : Artenac c10 (MIS 5c ; Ungulate NISP = 1301), Peyre (MIS 5e ; Ungulate NISP = 2815), Grotte aux Puces, réseau supérieur (100ka ; Ungulate NISP = 2360), Fouvent (MIS 3 ; Ungulate NISP = 3347) and Conives (MIS 3 ; 1717). To characterize objectively the taphonomic signature of fossil hyenas, two other older series (Middle Pleistocene), were briefly considered (Ceyssaguet (Pachycrocuta brevirostris) and Lunel-Viel 1 (Crocuta spelaea intermedia)) as well as two bone samples produced by other large Carnivores (the European jaguar (Panthera onca gombaszoegensis) of Artenac I and II and the modern wolf (Canis lupus) of Poland). Comparisons of those bone assemblages created by Hyenids (modern Crocuta: 139 dens, modern Hyaena: 63 dens; modern Parahyaena: 68 dens ; Crocuta crocuta spelaea: 30 sites), Felidae and large Canids allow to reconsider the criteria of characterization usually used in archaeological Taphonomy. It seems that Carnivores share common taphonomic characteristics (toothmark morphometry, morphotypes of consumption, sketelal parts of preys), and ttherefore those criteria donot appear favorable to a specific or/and generic identification of Carnivores having consumed bones. The (fossil) hyena osteophagic behavior distinguishes itself from that of the other large predators by: an important production of shaft fragments, the recurring presence of coprolithes and finally a high number of ingested bones. Among the latter, the anatomical spectrum of regurgitated elements on one hand as well as their degree of dissolution mattering on the other hand characterizes significantly the paleontological series produced voluntarily by hyenas These criteria could constitute the elements of diagnosis taphonomique the most interesting.
134

A taphonomic approach to reconstructing Upper Palaeolithic hunter-gatherer fishing strategies : a load of old trout!

Russ, Hannah January 2010 (has links)
In many cases in the past fish bones recovered during archaeological excavations at Upper Palaeolithic sites were often assumed to result from human activity without any consideration for alternate accumulation processes. Many of these assemblages had not been analysed in a scientifically rigorous manner, with some receiving no consideration at all. A review of current evidence and results of new analyses indicate that salmonids (salmon and trout) are the most frequently recorded fish at the European Palaeolithic cave sites. Two potential accumulation agents for fish remains were explored: brown bears (Ursus arctos) and eagle owls (Bubo bubo). Controlled feeding experiments integrated with ecological studies indicate that salmonid remains survive the digestive systems of both species and result in distinctive patterning in assemblage characteristics. Post-depositional taphonomic processes, such as trampling, also produce distinct taphonomic signatures and are an agent of differential inter-species preservation. A thorough consideration of depositional and post-depositional processes of archaeological assemblages in central Italy (Grotta di Pozzo, Maritza, La Punta and Ortucchio) and Spain (El Juyo, Altamira, Salitre, Castillo and Rascaño) shows that the fish remains from these sites result from human activity. The overrepresentation of cranial elements at the Italian sites suggest that fish were processed by removing the head to perhaps smoke or dry before transportation to other locations for consumption. This research lead to improved methods of analysis, and thus enhanced understanding of the role of fishing and fish consumption in Upper Palaeolithic hunter-gatherer societies.
135

An Investigation into Predation, Mortality and Taphonomic Bias inthe Population Distribution of Neptunea contraria from theRed Crag of East Anglia / Påverkan av predation, dödlighet och tafonomihos Neptunea contraria från Red Crag, England

Seale, Alexander January 2016 (has links)
Predation is a key factor in evolutionary dynamics. It disrupts the potential of fossilisation in prey items and is poorly recorded in the fossil record; failed predation in conical marine gastropods is recorded in scars. Quantifying the scar distribution and collection and taphonomic biases present in the fossil record of the gastropod Neptunea contraria, of the Red Crag Formation, Gelasian, Pleistocene, UK is necessary to approach this dynamic. Neptunea contraria is highly abundant in the Red Crag Formation which is easily accessed. The size and scarring on a large number (450+) of individuals was collected, recorded and measured from pre-existing and new material. The size distribution of Neptunea contraria is non-normal and is enriched in larger individuals, the scar distribution – expected to be Poisson – is not so. Taphonomic and Collection bias had a large influence over the size and scar distributions of Neptunea contraria. Material from the same localities shows very different size distributions. The lack of Poisson distribution suggests different rates of unsuccessful predation over life history of Neptunea contraria, assuming the data is valid. / Predation anses vara en viktig faktor inom ekologi och evolution men till vilken grad har effekterna av predation förändrats genom geologisk tid? Det centrala fokuset i denna studie ligger i att frambringa en förståelse av både population- och predationsfördelningen bland marina snäckor av arten Neptunea contraria av Pleistocen ålder från Red Crag-formationen, East Anglia, Storbritannien.Framgångsrik predation resulterar i förstörelsen av snigeln och dess livshistoria registreras i deras skal. Misslyckad predation bevaras i skalen bland individer som överlevt genom ärrbildningar. Det finns ett okänt samband mellan misslyckad och framgångsrik predation.Samlingen av fossilt material från Sedgwick-museet i Cambridge, Storbritannien, ligger till grund för denna studie. Detta material är ofullständigt (d.v.s. material saknas) och noterbart fragmenterat vilket orsakats av nedbrytande processer, därav tafonomi. Denna studie belyser flertalet källor som ger upphov till ett ofullständigt fossilt register, därav processer direkt relaterade till fossilisering och antropogen insamling. Genom att jämföra flertalet uppsättningar av fossilt material som insamlats av olika personer så kan graden av bias i förhållande till insamlingen undersökas. Resultatet av denna studie visar att samlingen av fossila sniglar som för närvarande finns på Sedgwick-museet är ofullständig. Detta är ett tillstånd som uppkommit delvis på grund av inkomplett insamling.Fördelningen av ärr orsakade av misslyckad predation förväntades följa en poissonfördelning. Denna förutsägelse motsägs sannerligen av nuvarande data. Troligtvis har detta förorsakats av en låg ”miss-lyckad predationsfrekvens”, vilket antyder att graden av predation inte är konstant.Sniglar av en större storlek saknar ärr på den övre delen av sina skal, vilket tyder på att frekvensen av misslyckad predation var låg i de juvenila stadierna. (
136

Occupations humaines de l’Oldowayen ancien et facteurs en-vironnementaux : interrelations et évolutions à partir des en-sembles archéologiques de la Formation de Shungura (Basse Vallée de l'Omo, Éthiopie) / Early oldowan human occupations and environmental factors : interrelation and evolution based on the archeological data of the Shungura Formation (Lower Omo Valley, Ethiopia)

Maurin, Tiphaine 22 December 2017 (has links)
Dans la Formation de Shungura l’apparition du comportement de taille de la pierre coïncide avec l’apparition de l’Oldowayen ancien et se concentre sur un laps de temps relativement resserré (Membre F et partie inférieure du Membre G ; 2,32 Ma à 2 Ma), bien que les hominidés fossiles soient présents tout au long de la séquence (3,6 à 1 Ma). Afin de questionner les interrelations et l’évolution entre les occupations humaines de l’Oldowayen ancien et les facteurs environnementaux, une approche multi-scalaire a été développée. Elle permet d’intégrer les très nombreuses données archéologiques (une centaine d’occurrences dans le Membre F et une cinquantaine dans la partie inférieure du Membre G) et paléoenvironnementales (incluant plusieurs milliers de spécimens pa-léontologiques des Membres E et F et les données géologiques de terrain). Selon le degré de préci-sion spatio-temporelle de ces différents registres de données, trois échelles d’analyse ont été rete-nues (complexe archéologique, zone d’étude, formation). L’analyse spatiale et taphonomique des données archéologiques couplée à l’analyse des cortèges fauniques a permis de démontrer que seul un petit nombre d’occurrences correspond à des occupations initiales dans le Membre F. Elles sont localisées à la base du Membre F, à proximité du paléo-fleuve Omo, dans un contexte général d’ouverture et d’aridification croissantes du milieu. À cela s’ajoute une répartition spatiale différen-tielle de certains taxons entre la partie nord et la partie sud de l’aire Type, qui pourrait être le mar-queur d’une plus grande emprise des zones humides dans le paysage de la partie sud de la Formation de Shungura. / The appearance of stone tool making behavior In the Shungura Formation coincides with the appearance of the early Oldowan. It lasts over a limited time period (Member F and the lower part of Member G: 2.32 Ma to 2 Ma), while hominid fossils are present in all members, from 3.6 Ma to 1 Ma. A multi-scalar approach was developed for assessing potential interrelations and co-evolution be-tween Early Oldowan human occupations and environmental factors. This approach has allowed to include an extensive set of archaeological and paleoenvironmental data (a hundred of occurrences in Member F and ca. fifty occurrences in the lower part of Member G, thousands of faunal remains from Members E and F, and field geological data). Depending on the spatial and temporal resolution of these different records, I have defined three scales of analysis, from archeological complex scale, to study area and formation scales. The combination of spatial and taphonomical analyses of archeo-logical data, coupled with the analysis of faunal assemblages, suggest that only few archeological occurrences correspond to primary occupations in Member F. They are all located in the lower part of Member F, in the vicinity of the Omo paleoriver, in a global context of opening up and drying of the environment. Additionally, the differential spatial distribution of several faunal taxa between the northern and southern parts of the Type area could mark a greater extension of wet areas in the southern part of the Shungura Formation.
137

Peleoecologia de mamíferos viventes como ferramente na caracterização do ambiente holocênico de Lagoa Santa / Paleoecology of mammals as a tool of holocenic environment characterisation at Lagoa Santa, MG

Perez, Cassiana Purcino 16 April 2009 (has links)
A região de Lagoa Santa, em Minas Gerais, tem um papel importantíssimo nos estudos paleontológicos e arqueológicos brasileiro. A compreensão da evolução paisagística regional durante todo o Holoceno é crucial para avançarmos nas questões levantadas a mais de 150 anos por Peter Lund. Apesar de décadas de intensa pesquisa relacionada às mudanças ambientais ocorridas durante o Quaternário Brasileiro, no entanto, a falta de precisão no controle cronológico e na resolução temporal dos estudos paleoambientais têm causado dificuldades no estabelecimento da paisagem presente e sua evolução nos últimos 10.000 anos. O estabelecimento de um quadro paleoecológico para a região de Lagoa Santa é fundamental para a compreensão do desenvolvimento e da organização das primeiras sociedades caçadoras-coletoras do continente. Dado esse cenário, o principal objetivo do presente estudo foi reconstituir as mudanças paleoambientais ocorridas na região de Lagoa Santa durante o Holoceno, baseado na paleoecologia da comunidade de mamíferos viventes de dois conjuntos fossilíferos. Como objetivo secundário, foi avaliada a influência dos processos tafonômicos pré- e pós-deposicionais na interpretação do ambiente pretérito a partir do registro faunístico fóssil. Os dados foram obtidos a partir dos conjuntos fósseis de um sítio paleontológico (Gruta Cuvieri) e um sítio arqueológico (Lapa do Santo), ambos na região de Lagoa Santa. A reconstrução paleoambiental baseou-se na variação da abundância relativa dos principais taxa de mamíferos presentes no registro fóssil de ambos os sítios, utilizando como unidades analíticas o NISP (number of identifiable specimen) e o MNI (minimum number of individuals). Os processos tafonômicos pré-deposicionais foram analisados qualitativamente, enquanto os processos pós-deposicionais foram analisados quantitativamente através do grau de fragmentação dos elementos ósseos, utilizando a abundância relativa de elementos esqueletais completos (WSE whole skeletal elements) em 3 relação ao NISP, para cada táxon. Os processos tafonômicos responsáveis pela formação dos sítios estudados, não mostraram afetar a análise paleoambiental realizada neste trabalho. Os resultados paleoambientais indicaram que a abundância relativa do NISP dos taxa analisados foi diretamente afetada pelo grau de fragmentação, sugerindo ser o NISP uma unidade analítica a ser evitada nos estudos de reconstituição paleoambiental. Em contra partida, a análise da variação de abundância relativa utilizando o MNI não foi afetada pelo grau de fragmentação dos elementos ósseos. Pelos resultados obtidos vê-se que a utilização da unidade analítica MNI é mais apropriada para estudos paleoambientais realizados a partir da variação de abundância de restos ósseos de mamíferos. A análise paleoambiental, utilizando o MNI, evidenciou um clima homogêneo na região durante o Holoceno Inicial e o Holoceno Médio, com incremento da umidade durante o Holoceno Tardio. / Lagoa Santa region in Minas Gerais plays an important role in Brazilian paleontological and archaeological studies. The understanding of regional landscape evolution during the Holocene is crucial for advancing issues raised 150 years ago by Peter Lund in the region. Despite decades of research on quaternary environmental changes, an understanding of the establishment of todays landscape and its evolution during the past 10,000 years has been hampered by the lack of accurate chronological control and temporal resolution in paleoenvironmental studies. A paleoecological reconstruction for the Lagoa Santa region is key to understand the development and the organization of the first hunter-gathered societies of the continent. Aiming at filling up this gap, the main objective of this study is to reconstruct the paleoenvironmental changes in Lagoa Santa region during the Holocene based on the paleoecology of mammal community of two fossiliferous assemblages. In addition, the pre-burial and post-depositional taphonomic processes associated with the two assemblages were assessed in order to understand the influence of these two variables in the interpretation of the past environment. This study examines the fossil material exhumed from a paleontological site (Gruta Cuvieri) and an archaeological site (Lapa do Santo), both found within the Lagoa Santa region. The paleoenvironmental reconstruction was based on the variation of relative abundance of the main mammals taxa found at both sites, using analytical tools such as NISP (number of identifiable specimen) and MNI (minimum number of individuals). The pre-burial taphonomic processes were analyzed qualitatively, while the postdepositional taphonomic processes were analyzed quantitatively based on abundance of whole skeletal elements (WSE) relative to NISP, for each taxon. The results show that taphonomic processes responsible for site formation did not affect the paleoenvironmental analyzes, and that the relative abundance of NISP is directly affected by the degree of bone fragmentation, 5 thus, suggesting NISP to be a poor analytical tool for paleoenvironmental reconstruction. On the other hand, the analysis of the relative abundance variation based on MNI was not affected by the degree of bone fragmentation. These results suggest that the MNI is more reliable analytical too for paleoenvironmental reconstruction based on the variation of abundance of mammal fossils. Finally, the paleoenvironmental analysis based on MNI revealed a homogeneous climate in the region during the Early and Middle Holocene, and moisture increase during Late Holocene.
138

Caracterização tafonômica e estratigráfica de Cloudina lucianoi (Beurlen & Sommer, 1957) Zaine & Faircild, 1985, no Grupo Corumbá, ediacarano do sudeste do Brasil

Meira, Felipe van Enck 18 October 2011 (has links)
Estudos do fóssil-índice Cloudina Germs 1972, do Neo-ediacarano, representado no Brasil por Cloudina lucianoi (Beurlen & Sommer) Zaine & Fairchild 1985, foram realizados nos calcários da Formação Tamengo, Grupo Corumbá, SW Brasil, nas pedreiras de Saladeiro, Corcal e Laginha na região de Corumbá, MS. Cloudina foi encontrada em cinco fáceis, previamente definidas por outros autores, na Formação Tamengo: grainstones oolíticos, calcários cristalinos maciços, packstones bioclasticos, ritmitos de mudstone calcífero/ folhelhos e mudstones com Cloudina. Estas fáceis foram depositadas numa variedade de contextos deposicionais numa rampa carbonática marcada por depósitos frequentes provocados por tempestades (representados pelos calcários cristalinos maciços e packstones bioclasticos) e caracterizada por bancos e baixios de ooides, que, em direção ao continente, protegiam um habitat calmo não apenas para Cloudina e esteiras microbianas e trombólitos associados, mas possivelmente para o outro metazoário na formação, Corumbella, também. Dentre as descobertas paleontológicas desta pesquisa, destacam-se duas: 1) Uma espécie nova de Cloudina, C. latilabrum nov. sp., caracterizada por seu diâmetro estreito e extensas abas finas partindo da borda distal dos segmentos sucessivos que constituem a concha; 2) A coexistência de fragmentos de colônias de cianobactérias e intraclastos tromboíticos com conchas de Cloudina, uma ocorrência coerente com a bem conhecida associação Cloudina-trombólitos, presente em Namíbia, Canadá e Omã. Fósseis de Cloudina são fragmentos em sua grande maioria, em razão dos processos de transporte, mas espécimes da nova espécie, aparentemente inteiros, e possivelmente autóctones, foram observados na fácies de mudstones com Cloudina, e espécimes quase completos constituem um tempestito na forma de coquinito (packstone bioclástico). Acontribuição estratigráfica mais importante desta pesquisa foi a descoberta de Cloudina na Formação Guaicurus, acima da Formação Tamengo, descoberta esta que estende a biozona de Cloudina até quase o topo do Grupo Corumbá / New studies of the late Ediacaran index fossil Cloudina Germs 1972, as represented in Brazil by Cloudina lucianoi (Beurlen & Sommer) Zaine & Fairchild 1985, were carried out in the limestones of the Tamengo Formation, Corumbá Group, SW Brazil, in the Saladeiro, Corcal and Laginha quarries near Corumbá, MS. Cloudina was found in five facies of this formation previously defined for this region: ooid grainstones, massive crystalline limestone, bioclastic packstones, calciferous mudstone / shale rhythmites, and mudstones with Cloudina. These facies were deposited in a variety of depositional settings on a carbonate ramp marked by frequent storm deposits (represented by the massive crystalline limestone and bioclastic packstone facies) and characterized by banks and shoals of ooid grainstones that landward provided a calm protected habitat not only for Cloudina and associated microbial mats and thrombolites, but also possibly for Corumbella as well. Paleontological discoveries of this research include: 1) a new species of Cloudina, C. latilabrum nov. sp., characterized by narrow diameter and flanges flaring outward from the distal borders of successive segments of the shell; 2) fragments of cyanobacterial colonies and thrombolitic intraclasts together with shells of Cloudina, an occurrence consistent with the well-known Cloudina-thrombolite association of Nambia, Canada, and Oman. Fossils of Cloudina are mostly fragmented as the result of transport, but apparently whole, possibly autochthonous specimens of the new species were observed in the mudstone facies, and nearly complete specimens comprise a coquinite storm deposit (bioclastic packstones). The most important stratigraphic contribution of the present research is the discovery of Cloudina in the Guaicurus Formation overlying the Tamengo Formation, thereby extending the Cloudina biozone almost to the top of the Corumbá Group.
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Taphonomie osseuse humaine au micro-scanner / Human bone taphonomy with microCT

Le Garff, Erwan 10 December 2018 (has links)
Introduction : l’estimation du délai post mortem (délai entre la découverte d’un cadavre et le moment du décès) est un élément important dans une enquête de police. Cette estimation est difficile lorsque le corps retrouvé est à l’état de squelette. Il existe peu d’outil pour effectuer cela.Ce travail s’inscrit dans la volonté d’élaborer des méthodes d’estimation de l’intervalle post mortem sur des restes osseux. Cette thèse s’attache à apporter des données nouvelles à l’aide de la micro-imagerie en taphonomie osseuse. Plus particulièrement, nous tentons de mettre en évidence les interactions entre l’os humain post mortem et son environnement.Matériels et méthodes : Des os humains issus de plusieurs dons du corps à la science ont été étudiés au micro-scanner. Ces os ont été conservés prospectivement pendant des périodes connues de temps connues. Les os ont été examinés au décours d’une conservation dans un environnement contrôlé et stable en température et en hygrométrie. Quatre axes d’expérimentation ont été retenus.Un premier axe de travail a porté sur la mesure de la précision du micro-scanner lors de mesures répétées. Ce travail a été réalisé sur des fragments de voûtes crâniennes et des phalanges.Un deuxième axe de travail a été réalisé sur l’impact du mode de conservation initiale de l’échantillon. Nous avons comparé l’évolution architecturale au micro-scanner de fragments de voûte crânienne conservés dans du formol à 10% ou en congélation à -20°C. Chaque échantillon a été conservé pendant 12 mois.Un troisième axe de travail s’est attaché à décrire l’évolution micro-scannographique de fragments osseux conservés en milieu standard sur diverse période (fragments de voûte crânienne sur 4 semaines et 10 semaines - fragments de côtes sur 6 et 36 mois).Résultats : Il a été mis en évidence que les acquisitions faites au micro-scanner sont précises et reproductibles.Nous avons montré qu’il existe de nombreuses variations architecturales lors de la mise en conservation d’os en milieu formolé ou en congélation. Cela montre l’importance du travail sur os frais dans un contexte taphonomique.Il a été mis en évidence des modifications architecturales significatives lors de la conservation d’os en milieu dit standard et contrôlé. Ces modifications surviennent dès les deux premières semaines de conservations pour les fragments de voûtes et sont également observées après 6 et 36 mois de conservation pour les fragments de côtes.Discussion et conclusion : Ce travail a permis de mettre en évidence l’intérêt que représente la micro-imagerie pour l’étude de l’architecture osseuse. Il s’agit d’une technologie précise et non destructrice de l’échantillon. L’apport du micro-scanner réside dans la capacité d’analyse architecturale de volumes importants. Nos résultats confirment l’influence du milieu de conservation et du temps sur le substrat osseux. Des modifications architecturales sont déjà observables après des temps de conservation variables (de quelques semaines plusieurs mois). Ces délais sont très courts au regard du délai de prescription en matière pénale et de la taphonomie en archéologie. Ces résultats méritent d’être confrontés à des données sur un plus grand nombre d’individus, sur des durées de conservation plus longues et avec de nombreux milieux de conservation. / Introduction: Estimating post-mortem delay (the time between the discovery of a dead body and the time of death) is an important element in a police investigation. This estimate is difficult when the body found is in the skeleton state. There is little tool to do this.This work is part of the desire to develop methods for estimating the post mortem interval on bone remains. This thesis focuses on providing new data using micro-imaging in bone taphonomy. In particular, we try to highlight the interactions between post mortem human bone and its environment.Materials and methods: Human bones from several body donations to science were studied by micro-scanning. These bones have been conserved prospectively for known periods of time. The bones were examined during conservation in a controlled environment and stable in temperature and hygrometry. Four axes of experimentation were retained.A first line of work focused on measuring the precision of the micro-scanner during repeated measurements. This work was done on fragments of cranial vaults and phalanges.A second line of work was carried out on the impact of the initial mode of preservation of the sample. We compared the architectural evolution with micro-scanning of cranial vault fragments preserved in 10% formalin or freezing at -20 ° C. Each sample was kept for 12 months.A third line of work focused on describing the microCT evolution of bone fragments preserved in standard medium over various periods (cranial vault fragments over 4 weeks and 10 weeks - rib fragments over 6 and 36 months).Results: It has been shown that micro-scanner acquisitions are accurate and reproducible.We have shown that there are many architectural variations in the storage of bone in formaldehyde or freezing. This shows the importance of fresh bone work in a taphonomic context.Significant architectural modifications have been demonstrated during bone conservation in a standard and controlled environment. These changes occur as early as the first two weeks of storage for the vault fragments and are also observed after 6 and 36 months of storage for the rib fragments.Discussion and conclusion: This work has made it possible to highlight the interest that micro-imaging represents for the study of bone architecture. This is a precise and non-destructive technology of the sample. The contribution of the micro-scanner lies in the capacity of architectural analysis of large volumes. Our results confirm the influence of conservation medium and time on the bone substrate. Architectural modifications are already observable after variable conservation times (from a few weeks to several months). These delays are very short with regard to the limitation period in criminal cases and taphonomy in archeology. These results deserve to be confronted with data on a larger number of individuals, longer storage periods, and many conservation environments.
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Actuopaleontologia em moluscos bivalves no complexo estuarino de Paranaguá: implicações paleoambientais e paleoecológicas em diferentes áreas de aporte energético / Actuopaleontology in bivalve mulluscs in the Paranaguá Estuarine Complex: paleoenvironmental and paleoecological implications in different areas of energy intake.

Marcondes, Andrea Thays Paganella 28 April 2015 (has links)
A Actuopaleontologia é o ramo da Paleontologia que visa aperfeiçoar as interpretações paleoambientais e paleoecológicas através das assinaturas tafonômicas, principalmente aquelas presentes em conchas bivalves. Tais estudos tafonômicos com bivalves marinhos têm sido conduzidos em ambientes sedimentares do Holoceno, porém, no Brasil, investigações similares são ainda incipientes, tendo sua predominância no litoral norte do Estado de São Paulo. O Complexo Estuarino de Paranaguá (CEP), situado na porção centro-norte do litoral do Paraná, possui feições fisiográficas distintas das encontradas no litoral norte do Estado de São Paulo. Com o objetivo de gerar dados comparativos entre os diferentes ambientes da costa brasileira, este estudo pretende caracterizar tafonomicamente as associações de moluscos bivalves em 11 pontos de coleta ao longo do CEP. Foram coletados oito litros de sedimento com a utilização de pegador de fundo tipo Petersen, em parceria com o Laboratório de Oceanografia Geológica (LOGeo CEM/UFPR). As assinaturas tafonômicas analisadas, podendo ser de origem química, física e/ou biológica, foram: articulação, tipo de valva, fragmentação, modificação da margem da concha, corrasion, perióstraco, brilho, cor, bioerosão, incrustação e predação. A ação dessas assinaturas pode resultar em outra assinatura tafonômica aqui analisada, a alteração da textura da superficial da concha. Foram analisados 150 bioclastos de cada um dos pontos de coleta, e cada assinatura tafonômica foi classificada individualmente. Os bioclastos foram peneirados em malhas de 2 mm para que as menores classes de tamanho não fossem excluídas das análises tafonômicas. Além dos bioclastos, foram coletadas amostras da água junto ao fundo dos locais amostrados, para registro de pH, salinidade, temperatura e turbidez. Ao total, 1.438 bioclastos foram utilizados nas análises tafonômicas e, das 11 estações de coleta, apenas duas não apresentaram o n mínimo de 150 conchas. Os dados abióticos não apresentaram grandes diferenças nas diferentes estações de coleta. A análise de cluster foi feita levando-se em consideração todas as assinaturas tafonômicas estudadas, e um dendograma geral relacionou os 9 pontos de coleta em que obteve-se o mínimo de 150 bioclastos. O dendograma gerado nesta análise mostrou quais as acumulações de moluscos bivalves e seus respectivos pontos de coleta estão mais semelhantes. Há um primeiro grupo formado pelas estações 683, 336, 482, 696 e 32. Com exceção da estação 32, as estações reunidas no primeiro grupo são os pontos de coleta mais próximos às desembocaduras do CEP, região de maiores profundidades e fortes correntes de marés. O segundo grupo é formado pelas estações 607, 152, 645 e 472, sendo pontos de coleta mais internos na área do CEP, próximos a ilhas, manguezais e bancos de areia. As assinaturas alteração da cor, brilho, modificação da margem, perióstraco e corrasion não parecem ser assinaturas úteis na identificação ou para uma possível caracterização dos diferentes ambientes do CEP. Isto porque elas não são variáveis entre esses diferentes ambientes. Houve predominância de desarticulação e fragmentação das valvas em todos os ambientes estudados, sendo possível que a fragmentação esteja sobre maior influência dos danos biológicos. Bioerosão e incrustação não apareceram em frequências expressivas, porém, apenas as estações de coleta próximas a desembocadura do CEP apresentaram bioeorosão, enquanto incrustação apareceu em todas as estações. A textura superficial da concha correlacionou-se positivamente com as assinaturas corrasion e bioerosão. / Actuopaleontology is the branch of Paleontology that aims to enhance paleoecological and paleoenvironmental interpretations, through the taphonomic signatures, especially those in bivalve shells. Such taphonomic studies with marine bivalves have been conducted in sedimentary Holocene environments, however, in Brazil, similar investigations are still incipient, having its predominance in the northern coast of São Paulo. The Paranaguá Estuarine Complex (CEP), situated in the north central portion of the Paraná coast, has different physiographic characteristics of those found in the north coast of São Paulo. In order to generate comparative data between different environments of the Brazilian coast, this study aims to characterize the taphonomy of bivalve mollusk associations from 11 collection stations along the CEP. Eight liters of sediment were collected with background catcher Petersen, in partnership with the Laboratory of Geological Oceanography (LOGeo - CEM/UFPR). The taphonomic signatures analyzed, which may be of chemical, physical and/or biological origin, were: articulation, valve type, fragmentation, edge modification, corrasion, periostracum, brightness, color, bioerosion, encrustation and predation. The action of these signatures may result in other taphonomic signature analyzed here, the alteration of shell superficial texture. 150 bioclasts were analyzed from each collection point and each taphonomic signature was individually classified. The bioclasts were sieved through mesh of two millimeter, so that classes of smaller size were not excluded from the taphonomic analyzes. In addition, water samples were collected at the bottom of each station for analysis of pH, salinity, temperature and turbidity. In total, 1,438 bioclasts were used in the taphonomic analysis and only two stations did not show the minimum n of 150 shells. Abiotic data showed no great differences in the different sampling stations. The cluster analysis was performed taking into account all studied taphonomic signatures, and a general dendrogram listed the collection points that showed the minimum of 150 bioclasts. The dendrogram generated in this analysis showed which accumulations of bivalve molluscs and their respective collection points are more similar. There is a first group formed by the stations 683, 336, 482, 696 and 32. With the exception of station 32, the stations on the first group are the closest to the mouths of the CEP, region of greater depths and strong tidal currents. The second group is formed by stations 607, 152, 645 and 472, being the more internal collection points, near islands, mangroves and sandbanks. The signatures color, brightness, edge modification, periostracum and corrasion do not seem to be useful in identifying or for a possible characterization of the different environments of the CEP, because they are not variable between these different environments. There was predominance of disarticulation and fragmentation of the valves in all study sites, being possible that the fragmentation was influenced more by biological damages. Bioerosion and encrustation did not appear in expressive frequencies, however, only the stations near the mouth of the CEP presented bioeorosão, while encrustation appeared in all stations. The surface texture of the shell was correlated positively with the sigantures corrasion and bioerosion.

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