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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 282 for “"fossils"”.
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Cretaceous bryozoan fossils from Needs Camp, South Africa
… Published literature regarding bryozoan fossils from South Africa comprise of four papers with the most recent being a little over two decades old. The upper and lower Needs Camp quarries in the Igoda Formation, situated about 20 km northwest of East London, is of great scientific …
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Newly discovered fossils provide novel insights on Cenozoic neotropical snakes
Las serpientes son un grupo de reptiles escamados con una enorme diversidad en el Neotrópico. Sin embargo, el registro fósil de estos vertebrados es escaso en el norte de Sur América. Aquí describo algunos fósiles de serpientes de tres diferentes localidades de Colombia. Primero, del Mioceno del …
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Ichnotaxonomic assessment of Mazon Creek area trace fossils, Illinois, USA
… preserved within siderite concretions. Trace fossils, though less well known, also occur in concretions. Several hundred trace-fossil-bearing concretions were examined from collections at The Field Museum, Chicago, and The University of Kansas Natural History Museum, Lawrence. Identification …
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Are 'exceptionally' preserved skeletal fossils necessarily exceptional chemically and cytologically?
At the macroscopic scale, vertebrate fossils are considered exceptional when non-biomineralized (soft) tissues are preserved. Histologically, high quality is defined by trueness to original shape of a bone, preservation of fine details (e.g. canaliculi), and presence or absence of matrix material …
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Earliest Cambrian - latest Proterozoic ichnofossils and problematic fossils from Inyo County, California
<p>A stratigraphic collection of ichnofossils and problematic body fossils was made from Lower Cambrian to Upper Proterozoic (<em>sensu</em> Cloud, 1973) strata of Inyo County, California. Specimens were collected from the Wyman, Reed, Deep Spring, and Campito Formations in the White-Inyo Mountains …
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Antarctic phytoplankton and climate change using Holocene sedimentary DNA, fossils and chemical proxies.
The West Antarctic Peninsula (WAP) is one of Earth’s fastest-warming regions, of particular concern given its marine-based ice sheets. Since the 1950s, mean air temperature has risen by ~2°C, and most glaciers are retreating with several ice shelves having already thinned or collapsed. Strengthened …
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Memory through re-use : food, fuel, fossils, filth and a few filling stations
This project engages disposable objects and concepts in the design process. Cultural items deemed unusable, obsolete, unfashionable, repugnant, toxic, or otherwise dirty are used as a resource and as a means to access collective memory. In this way the project will redefine for itself that which is …
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Quantifying periods of diffusion in marine and nonmarine vertebrate fossils using rare earth elements
… gradients are generally steeper in marine fossils than in terrestrial fossil bones, indicating longer periods of REE uptake in terrestrial fossils. Calculated periods of diffusion in terrestrial environments are 2.2 +/- 0.5 to 54.8 +/- 1.5 ka (based on a wetness factor of 0.5 +/- 0.1). …
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Constraining the Ediacaran-Cambrian boundary in South China using acanthomorphic acritarchs and Palaeopascichnus fossils
… strata of South China suggest that these microfossils may provide an appropriate biostratigraphic marker for the Ediacaran-Cambrian boundary, because of their wide distribution in chert-phosphorite layers intercalated with carbonates and shales, thus allowing their biostratigraphic occurrences …
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Plants and Fossils: Household Fuel Consumption in Hampshire and the West Riding of Yorkshire 1750-1830
The price and availability of different fuel sources shaped the material lives of English people during the Industrial Revolution. Fuel prices affected the location of industries, population growth and whether poorer people could afford to cook their own food. Fuel supplies were highly regionalized …
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From Fossils to Function: Exploring the Evolutionary And Functional Diversity Of HERV Envelope Proteins Across Primate Lineages
Endogenous retroviruses (ERVs) are remnants of ancient retroviral infections, passed down through the germline in a Mendelian manner. They are prevalent in vertebrates, making up about 8% of the human genome. The ERV genome typically includes four key protein-coding genes: gag, pro, pol, and env, …
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Investigating Microbial Trace-fossils and Abiotic Alteration in Hydrovolcanic Tuffs of the Fort Rock Volcanic Field, Oregon
Microbial ichnofossils in volcanic rocks provide a significant record of subsurface microbes and potentially extraterrestrial biosignatures. Here, the textures, mineralogy, and geochemistry of two continental basaltic hydrovolcanic deposits - Reed Rocks and Black Hills - in the Fort Rock Volcanic …
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Fossil preservation and the effects of groundwater leaching on fossils in the Yorktown Formation (Upper Pliocene), Virginia
… into how shells are altered. This study analyzes fossils in unconsolidated terrigenous sediments from the Virginia Coastal Plain, unlike previous studies conducted mostly in carbonate terranes. The vertical and lateral distribution of diagenetic states was mapped in an outcrop (63 m by 2.1 m) of …
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Contributions and New Methods in Paleontology: Geochemical, Ultrastructural, and Microstructural Characterization of Archean, Proterozoic, and Phanerozoic Fossils
… equipment–have been employed for numerous fossils over the entire range of geologic time, from microfossils to macrofossils and from the Archean (beginning at 3800 Ma) to the Cenozoic (ending at the recent). These techniques, predominantly used for geochemical, morphological, and …
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Paleoclimate Implications from Stable Isotope Analysis of Sedimentary Organic Carbon and Vertebrate Fossils from the Cedar Mountain Formation, UT, U.S.A.
<p>Oxygen and carbon isotopic compositions of fossilized vertebrate teeth and bone were analyzed to determine isotopic values of vertebrate faunal diet from the early Cretaceous Cedar Mountain Formation of Utah. Results for δ18O of PO4 (δ18Op) (Suarez et al., 2014) from the same data set have been …
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Using Geographical Information Systems to Investigate Spatial Patterns in Fossils of Tapirus polkenis from the Gray Fossil Site, Washington County, Tennessee
… early Pliocene time in eastern Tennessee. These fossils occur in sediments consisting of fine-grained clays and sands of lacustrine origin, which were deposited after multiple sinkholes formed in the underlying Knox Group basement carbonates. Three-dimensional nearest neighbor analysis has been …
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Using a multiproxy analysis of springbok fossils to track 2 million years of vegetation changes experienced by hominins in southern Africa.
A causal link between climatic changes and hominin evolution is an established one, yet the exact dynamics of this relationship is debated. Key climatic changes, such as the intensification of the Northern Hemisphere Glaciation, the onset of the Walker Circulation and the Mid-Pleistocene …
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Revision and description of Keuper (Middle Ladinian to Rhaetian) invertebrate trace fossils from the southern part of the Germanic Basin and studies of related material
The invertebrate trace fossils from the Keuper (Upper Triassic) of the southern part of the Germanic Basin are revised. The Keuper sediments of the Germanic Basin are predominantly composed of rocks representing various nonmarine environments dominated by red-bed facies. The Würzburg Formation, the …
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Digital reconstructions of fossil morphologies, Nama Group, Nambia
Previously undescribed fossils of weakly calcified metazoans were recently discovered in the terminal Proterozoic Nama Group of central and southern Namibia (Grotzinger et al., 1995), in sediments that contain the terminal Proterozoic index fossil Cloudina. The new fossils are closely associated …
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