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Problematické aspekty ichntaxonomie: tafosérie, "fotosérie" a "grafosérie"
Mikuláš, Radek
The probability of misidentification of trace fossils is extremely high if the authors did not see the original material but used only published photographs. Clearly, it is impracticable to visit all the collections containing the revised material and impossible to visit all type localities, but further caution against the use of photos or drawings must be done here. Photographed material can result in the effect named here “photoseries”: just the method of illumination of the object can make it classifiable as two different ichnotaxa. Diffuse light enables an annulate tunnel to be featured as Rhabdoglyphus, but raking light depicts instead “invaginated segments” of Fustiglyphus of idealized drawings is obviously even more problematic, as shown by nice “graphoseries” if we consider the original specimen, the method of its preparation, and the published figure.
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Echinoderm taphonomy in the Lower Cretaceous of Štramberk
Žítt, Jiří
Taphonomy of echinoderms (echinoids, asteroids, crinoids) from the Plaňava Formation and Kopřivnice Member (Upper Valnginian - Hauterivian)is evaluated. Principal taphonomic features of echinoderm remains (disarticulation, encrustation, fragmentation, abrasion) are studied, showing special characters in both sedimentary units.
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Microbiostratgraphical research of the Upper Cretaceous sediments of the Gosau Formation in the Northern Calcareous Alps, Austria
Hradecká, L. ; Svobodová, Marcela ; Švábenická, L.
Isolated outcrops of the sediments of the Lower (middle Turonian-Campanian)and Upper Gosau Subgroup were biostratigraphically evaluated on the base of the presence of foraminifers, calcareous nannoplankton and palynomorphs. The oldiest sediments corresponds to Middle Turonian (Eisenbach, Weissenbachalm), upper Coniacian was found in the Finstergraben, Weissenbachalm, upper Coniacian to Santonian in the Finstergraben, Hofergraben, Schattau, Nussensee, Weisenbachalm, Campanian age in the Hühnerkogel, Mooshuben aj., Maastrichtian in the Krampen, Grünbach-Neue Welt and the youngest sedeiments of the Paleocene age in Mooshuben and Grünbach-Zweiersdorf.
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The earliest growth stages of amphiporids and archaeocyaths - a comparison
Hladil, Jindřich
The initial growth stages of amphiporids and archaeocyaths are mutually similar to identical. They both consist of (1) rudimentary bottom disc (covered by small tubercles or septum-like bulges), (2) first chamber, (3) smooth first tube and (4) an interval with relatively rapid metamorphosis to complex adult morphologies. Probably no sponges can produce such an earliest skeletal formation that consists of the first chamber and tube, both resembling an external wall, because the typical sponge gemmules usually produce a number of cells that expand laterally very fast, forming a soft network, and it is a very different process. The great degree of similarity between the earliest growth stages of amphiporids and archaeocyaths suggests that there was a sharply separated group of "archaeocyathid-amphiporid" organisms (working name "Amphicyathida"), which was different from other corals, sponges or stromatoporoids.
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Mercury content and speciation in contaminated soils
Hojdová, Maria ; Rohovec, Jan ; Navrátil, Tomáš
The study deals with the determination of Hg distribution and speciation in soils with different level of contamination in the CR. The highest concentrations of Hg were found in topsoil horizons and declined with increasing depth and decreasing content of humus. Thermodesorption analysis distinguished Hg2+ weakly bound to clay minerals from Hg bound to organic matter or sulfides.
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