Trace Fossils
Mostrando 1-9 de 9 artigos, teses e dissertações.
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1. Fossils in quaternary micrites of Bodoquena Range, Bonito-MS and their application in paleoenvironmental studies / Fósseis em micritos quaternários da Serra da Bodoquena, Bonito-MS e sua aplicação em estudos paleoambientais
Bonito town and surrounding areas in Mato Grosso do Sul state are tourist attractions related with many quaternary carbonate deposits which form waterfalls, dams and render almost zero turbidity waters. That area is part of the National Park of Bodoquena Range and Pantanal Biosphere Reserve (UNESCO). Calcareous tufa are porous rocks formed by calcium carbona
Publicado em: 2009
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2. Caracterização tafonômica das concentrações fossilíferas da Formação Cape Melville, Grupo Moby Dick (Mioceno Inferior), Ilha Rei George, Antártica / Taphonomic characterization of fossil concentrations from the Cape Melville Formation, Moby Dick Group (Early Miocene), King Georg Island, Antactica
Works focusing on the taphonomy of fossil concentrations generated in glacial or periglacial environment are rare. In this context, the present dissertation carried out the taphonomic characterization of the fossil concentrations of the Cape Melville Formation, Moby Dick Group (Lower Miocene), King George Island, Antarctica, in order to elucidate the genesis
Publicado em: 2007
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3. Assinaturas icnológicas em depósitos glaciogênicos do grupo Itararé no RS
A revisão icnotaxonômica da paleoicnofauna Grupo Itararé no RS revelou a presença de uma icnofauna dominada por trilhas de artrópodes, com impressões de repouso e pistas de deslocamento intraestratal de artrópodes e escavações rasas de organismos vermiformes subordinadas, além de icnofábricas de Chondrites-Planolites-Palaeophycus. Duas novas icnoe
Publicado em: 2006
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4. Ediacaran biota from Sonora, Mexico.
The Ediacaran biota is the earliest diverse community of macroscopic animals and protoctists. Body and trace fossils in the Clemente Formation of northwestern Sonora extend downward the geologic range of Ediacaran forms. Taxa present in the Clemente Formation include cf. Cyclomedusa plana, Sekwia sp., an erniettid (bearing an air mattress-like "pneu" body co
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5. Trace fossils and substrates of the terminal Proterozoic–Cambrian transition: Implications for the record of early bilaterians and sediment mixing
The trace fossil record is important in determining the timing of the appearance of bilaterian animals. A conservative estimate puts this time at ≈555 million years ago. The preservational potential of traces made close to the sediment–water interface is crucial to detecting early benthic activity. Our studies on earliest Cambrian sediments suggest that
The National Academy of Sciences.
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6. Nondestructive, in situ, cellular-scale mapping of elemental abundances including organic carbon in permineralized fossils
The electron microprobe allows elemental abundances to be mapped at the μm scale, but until now high resolution mapping of light elements has been challenging. Modifications of electron microprobe procedure permit fine-scale mapping of carbon. When applied to permineralized fossils, this technique allows simultaneous mapping of organic material, major
The National Academy of Sciences.
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7. Pellet microfossils: Possible evidence for metazoan life in Early Proterozoic time
Microfossils resembling fecal pellets occur in acid-resistant residues and thin sections of Middle Cambrian to Early Proterozoic shale. The cylindrical microfossils average 50 × 110 μm and are the size and shape of fecal pellets produced by microscopic animals today. Pellets occur in dark gray and black rocks that were deposited in the facies that also pre
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8. Late Precambrian bilaterians: grades and clades.
A broad variety of body plans and subplans appear during a period of perhaps 8 million years (my) within the Early Cambrian, an unequaled explosion of morphological novelty, the ancestral lineages represented chiefly or entirely by trace fossils. Evidence from the fossil record can be combined with that from molecular phylogenetic trees to suggest that the l
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9. Bilaterians of the Precambrian—Cambrian transition and the annelid—arthropod relationship
The Late Proterozoic fossil record contains the remains of animals that may represent a grade of organization not found among living metazoans. These forms were segmented and large enough to require a hemocoel, yet evidently were not capable of forming penetrating burrows, which are essentially absent from contemporaneous sediments containing locally common