Orientador: José Xavier Neto / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-26T23:19:54Z (GMT). No. of bitstreams: 1 Maldanis_Lara_M.pdf: 4885819 bytes, checksum: 910f4a57ca690308f94da690a16295dd (MD5) Previous issue date: 2015 / Resumo: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: The complete Abstract is available with the full electronic digital thesis or dissertation / Mestrado / Farmacologia / Mestra em Farmacologia

1 Abstract In recent years, the term small carbonaceous fossils (SCFs) has been established to accomodate fragile organic-walled fossils of micro- to mesoscopic size that are usually extracted by means of the 'low-manipulation HF extraction' method. This method has so far only been utilized by several authors and no reports have been published on the usage of the method on samples from the Barrandian area. To test the applicability of the method, samples from the Barrandian area were processed. The samples came from eleven localities representing six stratigraphic units (Paseky Shale, Jince Formation, Letná Formation, Kosov Formation, Daleje Shale and Roblín Member). All the units have been studied before by 'standard' methods of palynological processing. Various previously unreported fossils are described, including wiwaxiid sclerites, putative chaetognath remains and acritarch clusters. Furthermore, it is discovered, that the 'low-manipulation HF extraction' can also be used for extraction of originally calcareous fossils. The pilot study provides a further proof that the 'low-manipulation HF extraction' is a useful tool with the potential to significantly expand our knowledge of fossil assemblages. Key words: Small carbonaceous fossils, Cambrian, Ordovician, Devonian, Barrandian area

Few studies utilise modern species distribution data and modeling to make predictions for examining potential fossil localities. Instead, species distribution modeling is often used for palaeoenvironmental interpretations. Using palaeoclimate data to model potential past distributions for a species provides a prediction showing areas where its fossil remains may be found. In this study, the current, Last Glacial Maximum, and Last Interglacial potential distributions of the arid steppe-obligate saiga antelope (Artiodactyla: Bovidae, Saiga tatarica) were modeled using the species distribution model Maxent. Few fossil records exist, but available fossil locality records were used to validate both palaeo models, resulting in speculative predictions about where the saiga may have lived. Known fossil localities of saiga from the Last Glacial Maximum time period were located within predicted moderately suitable environments, while four of seven Last Interglacial fossil localities were located within predicted moderately suitable environments, suggesting that models can accurately identify areas where fossils for the saiga can be found. Specifically, these models suggest saiga fossils may be located in northwestern and northeastern China, the western and central regions of the Middle East, and southern Alaska. The predicted areas in northeastern China are of particular interest because saiga fossils have not been identified in this region, but some palaeontologists theorize that northeast China may have been suitable for saiga in the past. The models lend credence to this argument.

Life on early earth has long been the topic of discussion for many researchers: how did it come to be? Which cells came first? Where can we find them? The most ancient rocks on our planet may hold some of the answers to these questions, but many may only be answered in laboratories. Chemical and morphological traces can be found from Archaean deposits, tantalisingly similar to modern day prokaryotes. Often, they are interpreted as the fossilised remains of bacteria or archaea. However, the caveat remains the abiotic mechanisms with which many similar traces and markers can be formed. The purpose of this thesis was to look into the similarities and differences in abiotic and biological formation of filamentous structures in rocks and observe whether there are chemical or morphological factors that allow for distinguishing between the two. Various laboratory methods were used: chemical gardens to form filamentous abiotic structures and experimental mineralisation of a filamentous methanogen in carbonate, phosphate, and silicate in order to compare and contrast the various mineralisation mechanisms in the fidelity of preservation of the microbes. In the former experiment, analysis with electron paramagnetic resonance (EPR) spectroscopy was carried out to identify potential chemical biomarkers. A combination of scanning and transmission electron microscopy, energy dispersive X-ray (EDX) analysis, X-ray diffraction (XRD) and Raman spectroscopy were also used to analyse the minerals and precipitates formed in both sets of experiments. The results of this research indicate that morphology of filamentous structures and the chemical signatures in biominerals may not be reliable as biogenic indicators. Furthermore, the work on experimental mineralisation reveals the possible biases in the rock record of microbial preservation which is highly dependent on the structure of the cell wall, chemistry of the environment, and the mineral formed. Finally, this work has important outcomes for the search for biomarkers on earth and on other planets and for the recognition of pseudofossils versus microbial fossils in the rock record.

The Cambrian explosion not only shaped the ecosystems of the Phanerozoic, but fundamentally changed how biota interacts with the environment, including the substrate. Cambrian trace fossils Alectorurus and Syringomorpha as well as Ordovician-Silurian Daedalus represent novel modes of faunal interaction with the newly innovated shallow marine mixed-ground and have surprisingly limited stratigraphic ranges. This study investigates vertically oriented spreiten trace fossils from the Armorican Quartzite Formation near Castañar de Ibor, Spain and the File Haidar Formation near Hällekis, Sweden. Site and trace fossil description was conducted to compare and contrast their morphology, ecological relationships, and potential affinities. While all these fossils feature J-shaped vertically oriented spreiten structures, Alectorurus is the most closely comparable Cambrian ichnofossil to the largely Ordovician Daedalus due to their similarity in overall size, morphology, and sedimentary environment. Alectorurus represents the earliest known occurrence of animal behavior comparable to Daedalus within similar facies. This short-lived ichnofossils may have gone extinct due to complexifying trophic chains in the shallow marine realm as brought forth from heightened predation and land-plant derived organics. Interpretations of the affinity of Daedalus, regarding the construction, and ecological niche can be extended to Alectorurus and may be used to help piece together the construction, ecology and affinities of these enigmatic Cambrian and Ordovician trace fossils.

Pliocene-Pleistocene sediments in the southeastern Acambay graben, central Mexico have yielded mammal fossils, including Equus simplicidens, cf. Rhynchotherium, ?Camelops, Mammuthus sp., Bison sp., and Antilocapra sp. The fossiliferous sediments include a period of lacustrine sedimentation in the late Pliocene-early Pleistocene that interrupted fluvial and alluvial sedimentation during the early Pliocene and Pleistocene. The sediments deposited in this late Pliocene paleolake record a history of lake level fluctuations, shown by lithologic variations in lacustrine sediments and abundance of vertebrate burrows. Volcanic and tectonic events in the Acambay graben were the major controls on sedimentation during Pliocene-Pleistocene time. Various local volcanic structures produced source rocks for Pliocene-Pleistocene sediments, and intra-arc extensional tectonics caused basin subsidence. Blockage of stream drainages by lava flows or perhaps increased basin subsidence contributed to the appearance of and fluctuations in the lacustrine system during the late Pliocene. Diatom assemblages from lacustrine sediments indicate slightly higher precipitation and humidity than present-day conditions in the Acambay graben. Therefore, climatic forcing may have also contributed to the development of the late Pliocene paleolake in the Acambay graben. Pliocene-Pleistocene volcanic rocks in this part of the Acambay graben range from basaltic andesite to rhyolite. The calc-alkaline composition of these volcanic rocks is similar to others in the modern Mexican Volcanic Belt; they have a continental arc affinity, which is consistent with a tectonic setting within the Mexican Volcanic Belt. The major eruptive episode in the Acambay graben occurred during the early Pliocene, although volcanism, represented by small volcanic structures, continued until the late Pleistocene. This observed decline in volcanism in the Acambay graben correlates with a early Pliocene through Quaternary trenchward migration of volcanism in the Mexican Volcanic Belt.

Ice crawlers (Insecta: Grylloblattodea) are rarely encountered insects that consist of five genera representing 26 species from North America and Asia. Asian grylloblattids are the most diverse, but North American ice crawlers (genus Grylloblatta) are known for their adaptation to cold conditions. Phylogenetic relationships among grylloblattid species and genera are not known. Late Pleistocene glaciations had a major effect on the current Grylloblatta distribution, because their specific habitat requirements restrict them to small geographical areas. Six genes were sampled in 37 individuals for 18S rRNA, 28S rRNA, histone 3, 12S rRNA, 16S rRNA, and cytochrome oxidase II (COII) from 27 populations of Grylloblatta, three populations from Japan (genus Galloisiana), and three populations from Russia (genus Grylloblattina). An additional 35 individuals from these localities were sampled for COII only. Phylogenetic analysis with two mantophasmid outgroups in POY indicates monophyletic genera, with Grylloblatta as sister to Grylloblattina. Two major lineages exist within Grylloblatta: a clade in Northern California and Oregon and a clade in Washington and Oregon. One new species and up to six candidate spacies are possible based on these data. Fossils and geological events provide little evidence for dating grylloblattid divergence times. At least six Grylloblatta lineages existed before the end of the Pleistocene glaciation. Conservation status for each lineage is proposed, based on IUCN Red List Conservation Criteria.

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Thesis (MSc (Botany and Zoology. Palaeontology))--University of Stellenbosch, 2001. / The fossil sites and fossils reported here range from the Archaean to the Recent. Information is presented on the circumstances of the discovery of some fossil sites in Southern Africa. A number of fossil sites, some of which can no longer be studied, are photographically recorded. Some recorded sites were relocated, while failure to locate others is noted. The assemblages at selected fossil sites are compiled, including some additions to their floras and faunas. Certain individual fossils are illustrated and discussed. Techniques which are not standard are outlined.