Search publications of the members of the Royal Belgian institute of natural Sciences
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Calibration of sclerosponge oxygen isotope records to temperature using high-resolution δ18O data
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Class Calcarea
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Clase Calcarea
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Clase Demospongas
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Class Demosponges
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Incorporation du magnésium dans les squelettes calcitiques des échinodermes et des éponges hypercalcifiées
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Living hypercalcified sponges
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Biomineralization in living hypercalcified demosponges: Toward a universal mechanism?
- Massive skeletons of living hypercalcified sponges, representative organisms of basal Metazoa, are uncommon models to improve our knowledge on biomineralization mechanisms and their possible evolution through time. Eight living species belonging to various orders of Demospongiae were selected for a comparative mineralogical characterization of their aragonitic or calcitic massive basal skeleton. The latter was prepared for scanning and transmission electron microscopy (SEM and TEM), selected-area electron diffraction (SAED) and X-ray diffraction (XRD) analyses. SEM results indicated distinctive macro- and micro-structural organizations of the skeleton for each species, likely resulting from a genetically dictated variation in the control exerted on their formation. However, most skeletons investigated shared submicron to nano-scale morphological and crystallographical patterns: (1) single-crystal fibers and bundles were composed of 20 to 100nm large submicronic grains, the smallest structural units, (2) nano-scale likely organic material occurred both within and between these structural units, (3) {110} micro-twin planes were observed along aragonitic fibers, and (4) individual fibers or small bundles protruded from the external growing surface of skeletons. This comparative mineralogical study of phylogenetically distant species brings further evidence to recent biomineralization models already proposed for sponges, corals, mollusks, brachiopods and echinoderms and to the hypothesis of the universal and ancestral character of such mechanisms in Metazoa.
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New datings and considerations on the chronology of Upper Palaeolithic sites in the Great Eurasiatic Plain.
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Paléoenvironnement et chronologie du Paléolithique dans la Grande Plaine eurasiatique depuis 150.000 ans.
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Revised stratigraphy and chronology of the Willendorf II sequence, Lower Austria
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A New Hamburgian Concentration at Siedlnica 17 in the Kopanica Valley (SW Poland).
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Anthracology and Past Vegetation Reconstruction. In J. SVOBODA (ed.): Pavlov I. Northwest. The Upper Paleolithic burial and its settlement context.
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Advantages of high quality SWIR bands for ocean colour processing: Examples from Landsat-8
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SIMilarity Environment Correction (SIMEC) applied to MERIS data over inland and coastal waters
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Cloud and cloud shadow identification for MERIS and Sentinel-3/OLCI
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CoastColour Round Robin datasets: a database to evaluate the performance of algorithms for the retrieval of water quality parameters in coastal waters
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A SWIR based algorithm to retrieve total suspended matter in extremely turbid waters
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A single algorithm to retrieve turbidity from remotely-sensed data in all coastal and estuarine waters
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Salinity predicts the distribution of chlorophyll a spring peak in the southern North Sea continental waters
