Evolution of flight in maniraptoran dinosaurs is marked by the acquisition of distinct avian characters, such as feathers, as seen in Archaeopteryx from the Solnhofen limestone. These rare fossils were pivotal in confirming the dinosauria-avian lineage. One of the key derived avian characters is the possession of feathers, details of which were remarkably preserved in the Lagerstätte environment. These structures were previously simply assumed to be impressions; however, a detailed chemical analysis has, until now, never been completed on any Archaeopteryx specimen. Here we present chemical imaging via synchrotron rapid scanning X-ray fluorescence (SRS-XRF) of the Thermopolis Archaeopteryx, which shows that portions of the feathers are not impressions but are in fact remnant body fossil structures, maintaining elemental compositions that are completely different from the embedding geological matrix. Our results indicate phosphorous and sulfur retention in soft tissue as well as trace metal (Zn and Cu) retention in bone. Other previously unknown chemical details of Archaeopteryx are also revealed in this study including: bone chemistry, taphonomy (fossilization process), and curation artifacts. SRS-XRF represents a major advancement in the study of the life chemistry and fossilization processes of Archaeopteryx and other extinct organisms because it is now practical to image the chemistry of large specimens rapidly at concentration levels of parts per million. This technique has wider application to the archaeological, forensic, and biological sciences, enabling the mapping of "unseen" compounds critical to understanding biological structures, modes of preservation, and environmental context. trace elements | X-ray absorption spectroscopy A rchaeopteryx (1) are rare but occupy a pivotal place in the development of Darwinian evolution because of their possession of both reptilian (jaws with teeth and a long bony tail) and avian (feathered wings) characters (2). The specimen used in this study is considered to be the most complete and best preserved archaeopterygid (3) belonging to the species A. siemensii (4). Previous analyses of this fossil have relied upon visual inspection, X-ray computer tomography, scanning electron, and ultraviolet/ visible light microscopy. Structural studies have been extensive and strongly indicate that this organism is transitional between dinosaurs and birds; however, detailed chemical analysis has never been performed. Here we apply state-of-the-art synchrotron rapid scanning X-ray fluorescence (SRS-XRF) imaging to this remarkably well-preserved specimen revealing striking and previously unknown details about the chemical preservation of soft tissue, elemental distribution patterns most likely related to the organism's life processes, insights into the chemistry of the fossilization process, and details of curation history. In addition, quantitative chemical analyses and X-ray absorption spectroscopy are presented that not only corroborate the imaging results but also give further det...
Liquid-feed flame spray pyrolysis (LFFSP) of metalloorganic [N(CH2CH2O)3Al, alumatrane, and Al(Acac)3] and inorganic alumina [AlCl3 and Al(NO3)3·9H2O] precursors dissolved in 1:1 ethanol/THF, aerosolized with O2 and ignited can produce quite different alumina nanopowders during the ensuing combustion process. The metalloorganics appear to volatilize and combust easily to give nano-alumina, with particle sizes <20 nm and corresponding surface areas of ≈60 m2/g at rates of 50 g/h. In contrast, the nitrate appears to melt during combustion rather than volatilize, forming large, hollow particles typical of a spray pyrolysis process with particle sizes >70 nm and surface areas of ≈12 m2/g. AlCl3 appears to volatilize easily but does not hydrolyze rapidly in the flame leading to mixtures of alumina and recovered AlCl3. The resulting nanopowders consist of a mixture of transition alumina phases, primarily δ*, that could only be successfully identified and quantified by Rietveld refinement. Because the δ phase is not typically made as a high-surface-area material or in large quantities, it offers the opportunity to serve as a novel catalyst support. On heating to 1000 °C, the dominant phase becomes θ-Al2O3 that was clearly identified by 27Al MAS NMR using ab initio calculations of the 27Al NMR parameters derived from the X-ray structure. At present, the exact mechanism(s) whereby particles nucleate and grow, and phases form from the species generated during combustion, remains unknown.
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