A Large Trace Fossil in Nodular Limestones (Lower Devonian,Czech Republic): Sedimentological Consequences,Ethology and Taphonomy

Large star-like trace fossil was found on the upper bedding plane of nodular limestone of the Praha Formation (Pragian, Devonian) at Praha, Czech Republic. It was tentatively placed to the ichnogenus Capodistria. It is interpreted as a feeding trace that originated on the seafloor surface. The structure consists of 10–11 radial rays and its longer axis is 60 cm. The rays are preserved as concave epireliefs, up to 10 mm deep and 25 mm wide. The trace fossil partly intersects nodules that cover surfaces of most bedding planes of the Praha Formation, demonstrating that the nodules formed during the earliest stages of diagenesis.     

New species of syringoporids from Eifelian deposits of the Subpolar Ural Mountains

A high diversity of tabulate corals in Eifelian deposits of the Syv“yu River basin (Subpolar Urals) is reported for the first time. Most of the corals are represented by colonies of syringoporids. Five new species Syringopora parva sp. nov., S. insueta sp. nov., S. indecora sp. nov., Tetraporinus syvjuensis sp. nov., and Armalites serotinus sp. nov. are described.     

Seawater strontium isotope curve at the Silurian/Devonian boundary: a study of the global Silurian/Devonian boundary stratotype

Present application of ⁸⁷Sr/⁸⁶Sr chemostratigraphy to detailed stratigraphical tasks is limited by inaccurate calibration of the general seawater strontium curve to absolute as well as to relative time scales. For this reason, refinement of the general seawater strontium curve has been suggested, using mainly clearly defined global boundary stratotype sections. This study reports the first ⁸⁷Sr/⁸⁶Sr data from the global Silurian/Devonian boundary stratotype section and fills an existing 1-Ma gap in available data. Generally, the data from the stratotype fit the range interpolated from published ⁸⁷Sr/⁸⁶Sr data of the general curve, but the slight differences may suggest an existence of a high-order oscillation near the Silurian/Devonian boundary. Higher ⁸⁷Sr/⁸⁶Sr values in the Devonian part of boundary bed 20 (20-beta) may indicate an exotic material influx of recycled sediment.     

迄今世界最早被子植物花序化石的首次发现

首次报道迄今已知世界最早的被子植物花序化石。该花序花石产于甸黑龙江鸡西早白垩世城子河组,花序由数十枚小花组成,其花粉具典型的被子植物特征,无明确的萌发口器,根据其所在层位下伏海相层化石佐证,以及与以色列等地早期被子植物花粉化石的对比等。该花序持质时代可能为早白垩世晚期,或Ｈａｕｔｅｒｉｖｉａｎ晚期至Ｂａｒｒｅｍｉａｎ早期。文中还讨论了此花序及其花粉化石的发现在研究全球被子植物起源早期演化等的重要意     

Compostional variations and patterns of condont reworking in Late Devonian and early carboniferous calciturbidites (Moravia, Czech Republic)

Summary Compositional variations and grain-size properties of both carbonate constituents and conodonts as an alternative component group were used for interpreting the processes governing the deposition of upper Famennian and middle Tournaisian calciturbidites in Moravia, Czech Republic. Both the composition and grain-size properties of conodont element associations showed to be markedly dependant on facies type of their host sediment. Upper Devonian calciturbidite successions deposited on flanks of wide, Moravian-Silesian carbonate platform are composed mainly of echinoderm-and peloid-rich wacke/packstones and intraclastic float/rudstones (fine-grained calciturbidites, “normal” calciturbidites with Tab Bouma sequences, debris-flow breccias) with abundance of shelf-and shelf margin conodont taxa and epipelagic and “mesopelagic” conodonts. Upper Devonian calciturbidites deposited on slopes of volcanic sea-mounts are composed of echinoderm-and peloid-rich wacke/packstones and float/rudstones with increased proportion of intraclasts and volcanigenic lithoclasts (fine-grained calciturbidites, normal calciturbidites), yeilding abundant conodont associations with higher proportion of “mesopelagic” taxa compared to the platform-flank examples. Middle Tournaisian calciturbidite succession composed of crinoid-, peloid-, intraclast-and lithoclast-rich lime mudstones, wacke/packstones and float/rudstones (normal calciturbidites and debris-flow breccias) yielded conodont element associations rich in shelt-and shelf-margin taxa, “mesopelagic” conodonts and reworked Middle-and Upper Devonian conodonts. In general, the ratio of shelf-and shelf margin conodont taxa to “mesopelagic” taxa is distinctly lower in finegrained calciturbidites than it is in normal calciturbidites and debris-flow breccias. Grain-size properties (mean grain size and sorting) and percentage of fragmented conodont elements, too, are markedly dependant on the facies type: in fine-grained calciturbidites the values of mean grain-size and fragmentation are low and the sorting is good to very good whereas in normal calciturbidites and debris-flow breccias the values of mean grain-size and fragmentation are distinctly higher and the sorting is poorer. The interdependence of facies type and composition and grain-size properties of conodont element associations in gravity-flow deposits is explained as resultant from hydrodynamic sorting during turbidity current flow and final deposition of the bed. Compositional variations observed in our sections may thus be attributed to facies variability (coarsening-and thickening-upward trends) rather than to sea-level fluctuations (highstand shedding of carbonate platforms). On the other hand, significant enrichment in reworked conodont taxa in middle Tournaisian normal calciturbidites compared to scarcity and/or absence of such conodonts in essentially identical facies of upper Famennian age indicate sea-level to be the major control governing such compositional variations, with low relative sea-level stand in middle Tournaisian and high relative sea-level stand in upper Famennian. Thorough analysis of conodont evolution, palaeoecology and taphonomy, with emphasis on understanding the processes of deposition of their host rock, are recommended for any biostratigraphic and biofacies study to be done in carbonate sediments deposited under strong hydrodynamic regimes, such as calciturbidites, temperstites, debris-flow deposits, shelf-edge oolitic sands, tidal-channel facies etc.     

Epidemiology of Helicobacter pylori infection in the Czech Republic

BACKGROUND: Prevalence of Helicobacter pylori infection has been estimated to range from 60 to 95% in the former communist countries of Central and Eastern Europe. The aim of this study was to evaluate H. pylori infection prevalence in a representative sample of the Czech population. The second objective was to describe difference of H. pylori prevalence between different social groups of children and adults. MATERIALS AND METHODS: A total of 2509 persons aged 5-100 years, randomly selected out of 30,012 persons of the general population, took part in the study. H. pylori infection was investigated by means of 13C-urea breath test. Breath samples were analyzed by isotope ratio mass spectrometry. Social and demographic characteristics were based on data from self-completed questionnaires. RESULTS: Using the total Czech population as a standard, we estimated the age-standardized prevalence of H. pylori in males aged 5+ years at 41.9% (95% CI 39.0%, 44.8%) and in females aged 5+ years at 41.4% (95% CI 38.6%, 44.3%) in 2001. Prevalence of H. pylori increased with age but was not related to gender. Children of mothers with basic or lower education, living in crowded accommodations, without access to running warm water, and residing in smaller towns appear to be at the highest risk. Low education and heavy smoking are most strongly associated with prevalence of H. pylori positivity in adults and adolescents. CONCLUSIONS: This is a unique study based on a representative sample of the general population in a Central European country. The overall prevalence of H. pylori is lower than previously assumed and could partly reflect a substantial recent decrease in H. pylori prevalence in the Czech Republic. Consistent with earlier studies, H. pylori infection is strongly influenced by socioeconomic conditions and childhood poverty.     

Sedimentary and biofacies records in calciturbidites at the Devonian-Carboniferous boundary in Moravia (Moravian-Silesian Zone, Middle Europe)

Summary At the Devonian/Carboniferous boundary, major climatic and oceanographic changes influenced sedimentation on carbonate platforms and in peri-platfrom asreas. Three deep-water carbonate successions in Moravia, which were selected to represent different paleotectonic settings, have been studied with the aim of testing the influence of eustatic, climatic and tectonic controls on sedimentation and conodont paleoecology and taphonomy. On the slopes of the wide carbonate platforms of the Moravian Karst Development (Lesní lom and Grygov sections), an exemplary highstand shedding systems developed in the upper Famennian (expansa Zone), marked by a pronounced thickness of their respective calciturbidite successions and an abundance of shallow-water skeletal grains.Palamatolepis— andBispathodus-dominated conodont assemblages contain an admixture ofPolygnathus representing a transported, near-shore component. The eustatic sea-level fall in the praesulcata Zone and the lowstand conditions at the D/C boundary resulted in a decline of carbonate platform production and condensed deposition or nondeposition. In the Lesní lom section, a condensed sequence of turrbiditic calcarenites and shales (Middle praesulcata—lowermost sulcata Zone) was followed by lime mud calciturbidites (sulcata and duplicata Zones). In the conodont assemblages, the first event in the Lower praesulcata Zone was associated with the reduction of ‘mesopelagic’Palmatopic and a bloom of epipelagicPolygnathus communis. The second event in the Middle praesulcata Zone corresponds to the onset of polygnathidprotogranthodid biofacies, indicating a carbonate slope environment. In the Grygov section, a pronounced thickening and upward-coarsening succession of tubiditic calcilutites through calcarenites and intraclast breccias, with poor palmatolepid-bispathodid connodont assemblages (expansa Zone), indicates a progradation of the calciturbidite system associated with sea-level highstand. After a break in sedimentation, covering the interval from the Lower praseulcata to the base of Lower crenulata Zone, thick-bedded, fine-grained calciturbidites were deposited in the Lower crenulata Zone, and are associated with poor, mixed assemblages where siphonodellids and polygnathids predominate. At the isosticha-Upper crenulata/Lower typicus boundary, coasre grained, turbiditic calcarenites and breccias rich in clastic quartz grains and mixed conodont assemblages with reworked Frasnian and Famennian conodonts indicate a deep erosion of the source area, presumably due totectonic uplift (relative lowstand). In the Jesenec section, on the flanks of the volcanic seamount (the Drahany Development), a deep-water Upper Famennian condensed succession of calciturbidites and presumably winnowed pelagic limestones is marked by conodont assemblages of palmatolepid-bispathodid biofacies. More proximal calciturbidites with mixed deep-water and shallowwater conodonts prograde at the top of the Upper Famennian succession (Middle to Upper expansa Zone). A striking hiatus, covering the interval from the Early preaesulcata to the base of Lower crenulata Zone, resulted from extreme condensation and submarine bottom current erosion due to sea-level lowstand in the late Famennian and early Tournaisian. The renewed middle Tournaisian calciturbidite sedimentation with strong evidence of erosion at the source area indicates global eustatic rise and tectonic uplift of the Drahany Development seamounts (relative lowstand). The earlier occurrence of the uplift in the Jesenec area, relative to the Grygov section, shows the advance of tectonic processes over time in the Moravian-Silesian basin (orogenic polarity) as a consequence of Variscan orogenic movements.     

Bacterial origin of the Red Pigmentation in the devonian Slivenec Limestone, Czech Republic

Summary The deep-red lenses of the Pragian Slivenec Limestone have been extensively quarried for ornamental purposes since the XII^th century. Petrographic microscope observations indicate that the hematite stainings of the limestone follow ten different patterns. They range from massive non-directional filling of cavities to mineralized films and microstromatolites. Numerous ironrich endolithes are observed. Some could be derived from bacterial or lichen perforations and some related to ferric bacteria. Infiltration along welded calcite crystals, regular mineralized films and microstromatolites suggest a ferric bacterial origin for the pigment. This is confirmed by scanning microscope examinations of polished sections, that show hematite concentrations along micrometric filamentous sheaths.     

Le Paléolithique de la République Tchèque

Bohemia and Moravia, the two parts constituting together the Czech Republic, do not only represent historical countries, but they also display distinct geographies. As Bohemia is surrounded by mountains, its territory is often called the Bohemian Basin. In Moravia, the mountains in the north of the country are interrupted by the Moravian Gate, giving access to the Great Northern Plain of Europe with its rich sources of Northern flints, the best raw material for chipped stone industries available in Central Europe. The southern part opens directly towards the Danubian region with its more temperate environment, and connecting the south of Germany with the Balkans. The morphology of the territory had obviously influenced the Palaeolithic occupation. In the Lower and Middle Palaeolithic when communication did not play any major role, the two countries were settled relatively regularly, although not too densely. The Early Upper Palaeolithic brought a substantial change: In Moravia hundreds of sites proliferate, while there are only few of them in Bohemia. The Pavlovian phase of the Gravettian seems to be completely missing in Bohemia, while in Moravia it is concentrated in several megasites on the banks of the main rivers. This is certainly caused by the presence of the South-North artery of animal migrations and human communication. Since the Epigravettian, the density of occupation became balanced again. The local evolution of the Upper Palaeolithic was interrupted by the invasion of the Magdalenians coming from the West, on the one side along the Danube River, on the other by the northern route through Poland. The Late Palaeolithic, subject to influences coming from the North, gradually transformed into the Mesolithic.     

The tail of Microbrachis (Tetrapoda; Microsauria)

Previously undescribed specimens of the aquatic microsaur Microbrachis pelikani Fritsch from the Upper Carboniferous of Nýřany, Czech Republic, demonstrate the presence of a deep-swimming-adapted tail supported by up to 46 postsacral vertebrae. The tail appears to have lengthened with ontogeny. Most microsaurs appear to have been terrestrial and because the group has been perceived to be related to the amniotes, all (including Microbrachis ) had been reconstructed with slender tapering tails. Microbrachis appears to be an early offshoot of the microsaurs and it is unclear whether the deep tail is a primitive retention or an acquired characteristic of the genus.     

秦岭中泥盆世西汉水群中的几种四射珊瑚化石

本文描述了产自北秦岭中泥盆统西汉水群上部的10属12种四射珊瑚化石,包括3新种。由于其中出现了Temnophyllum waltheri, Grypophyllum tenue, Tabulophyllum annulatum和Disphyllum hsianghsienense等德国、苏联和我国南方Givetian阶的常见分子,因此,甘肃宕昌产上述珊瑚化石的地层时代应属于中泥盆世晚期。本文还根据笔者对保存在加拿大和德国等地自然博物馆中某些珊瑚属模式标本的观察和重新研究,讨论了一些珊瑚属种之间的亲缘关系并厘订了某些属征。     

Effects of different cultivation types on native and alien weed species richness and diversity in Moravia (Czech Republic)

Changes in weed species richness and beta-diversity are partly attributable to different types and intensity of disturbance and partly to broad-scale variation in environmental conditions. We compiled a data set of 434 vegetation plots of weed vegetation in root crop and cereal fields in Moravia (eastern Czech Republic) to compare the effects of environmental conditions and different disturbance regimes on species richness and beta-diversity. To detect changes in species richness, we related the variation in species richness to individual environmental conditions. To assess differences in beta-diversity between the vegetation of cereal and root crop fields, we used Whittaker's measure of beta-diversity. The relative importance of each environmental variable for the variation in species composition was evaluated using canonical correspondence analysis. All analyses were done for all vascular plant species and separately for native species, archaeophytes and neophytes. A comparison of weed vegetation of root crops and cereals showed a distinct dichotomy between these two types of weed vegetation. There was no significant difference in total species richness and native species richness; however, cereal fields were richer in archaeophytes and root crop fields were richer in neophytes. The beta-diversity of weed vegetation was higher in root crops. Environmental factors explained a significant part of the variability in richness of both natives and aliens. The richness of native species increased and beta-diversity decreased with increasing precipitation. The opposite relationship was found for archaeophytes, in both cereals and root crops. These results confirmed the importance of climatic factors and management practices for changes in weed species composition. They also showed a distinct pattern of species richness and beta-diversity of native and alien weed species.     

贵州独山泥盆纪生物地层以及珊瑚的四次灭绝事件的研究

贵州省独山县县城附近的泥盆纪浅海相地层发育良好,底栖生物化石丰富,研究历史悠久,是我国南方浅海相泥盆系的标准剖面之一。文章从珊瑚化石的角度进行生物地层和群落生态的分析,并建立独山中、晚泥盆世7个珊瑚组合。文章最后还着重阐述独山泥盆纪珊瑚的4次灭绝事件：1)mid-Eifelian event(发生在龙洞水段之顶);2)late-Givetian event(发生在鸡窝寨段之顶);3)F-Fevent(发生在靠近尧梭组之底);4)D-Cevent(发生在革老河组之顶)。其中,F-F大灭绝事件对珊瑚群的影响最大。     

Seasonal growth bands in Famennian rugose coral Scruttonia kunthi and their environmental significance

Large colonies of rugose coral Scruttonia kunthi occurring in the upper Famennian of Sudetes (southern Poland) reveal distinct growth banding in their skeletons. They were investigated for internal structural characteristics and stable isotopic composition. The skeletal tissue consists of alternating light and dark bands which differ in thickness, density and morphology of structural elements, and in occurrence of corallite contraction and rejuvenescense. Darker parts with densely arranged thick skeletal elements are thin in comparison to lighter parts. In addition, they include frequently offsets and contraction of corallites. A couplet of dense and less dense bands is interpreted to represent most probably an annual cycle. The calculated growth rate for Scruttonia kunthi varied from 6 mm/yr to 12 mm/yr. Growth-band formation was influenced environmentally. Oxygen isotopic data provide an evidence that high-density bands were formed in the season of higher environmental stress, with relatively warmer temperatures and higher sedimentation rates. Carbon isotopic signatures are very uniform, and thus enigmatic. They indicate that at least growth rate of the skeleton and seawater temperature had no influence on the coral δ¹³C.     

Spontaneous succession in Central‐European man‐made habitats: What information can be used in restoration practice?

Abstract. The results of previous studies concerning spontaneous vegetation succession in various man‐made or disturbed habitats in Central Europe are discussed in relation to restoration ecology. An attempt is made to answer the main questions which are important to restoration programs. These concern the rate and direction of succession; participation of target species and communities, woody species, ruderals and aliens; arresting or diverting succession; changes in species diversity; variability of successional pathways and the role of abiotic environmental conditions. The great potential for using successional theory in restoration programs is emphasized.     

Survival rates in the Czech Republic of introduced plants known as wool aliens

The paper analyses an unintentional experiment conducted 40 years ago with species termed wool aliens which were observed in employee garden allotments of a wool-processing factory in Brno, Czech Republic. The waste from processing was used as a garden fertilizer, and alien species were recorded by Dvořák and Kühn (1966) Zavlečené rostliny na pozemcích přádelny vlny ‘Mosilana’ n.p. v Brně. Preslia 38: 327–332. The survival of these species was assessed by their occurrence in the current alien flora of the Czech Republic. Of the 56 species introduced in the 1960s and classified as wool aliens, 18 are still present in the Czech alien flora. The remaining 38 species are considered extinct, i.e. alien plants not capable of long-term survival in the country. The resulting survival rate of wool aliens is 22.1%. Three species on the list (5.4%) were clearly capable of naturalization. Compared to the other alien flora of the Czech Republic, wool aliens were disproportionally introduced from Australia, Africa and South and Central America. Species from Europe and Africa tended to survive the best. Grasses were most strongly represented, contributing 62.5% to wool alien species but only 7.9% to the total Czech neophyte flora. All surviving species were annuals, whereas none of the perennials survived; the survival rate in annuals was 37.5%. Survival of species introduced with wool was significantly comparable to their performance in the UK and in Central Europe, indicating that survival is not determined by mere chance and that the same species tend to be successful elsewhere in Europe. Maximum height and the month of first flowering were not significantly related to the species survival. The role of specific events in the enrichment of alien floras is discussed.     

Ichnogenus Astropolichnus in the Middle Cambrian of the Barrandian area,Czech Republic

Imperfectly preserved specimen of a supposed hydrozoan Medusites cf. radiatus Linnars., originally described by Pompeckj (1896 Pompeckj, J. F. 1896. Die Fauna des Kambriums von Tej?ovic und Skrej in Böhmen. Jahrbuch der Keiserlichen-königlichen geologischen Reichanstalt, 45:495–615. [Google Scholar]) from the “Pod trním” locality near Tý?ovice (Slapnice Member of the Buchava Formation, Skryje–Tý?ovice Basin) is revised. Recent study of the original specimen and a more complete topotype specimen testify the affiliation to the pineapple-shaped ichnogenus Astropolichnus Crimes and Anderson, 1985. A new ichnospecies A. bohemicus is established on the material from the Buchava Formation. This material is the first occurrence of Astropolichnus in the middle Cambrian as well as the first report of this ichnogenus in the Barrandian area of Czech Republic.     

Terrestrial insect bioerosion and the possibilities of its fossilization (Holocene to recent,Czech republic)

Cylindrical tunnels, representing bee's nests, are present at and immediately beneath exposed surfaces of Late Cretaceous castellated sandstones in the Czech Republic. The tunnels originated either in weathered rock of overhanging surfaces, or in a thin layer of weathered sandstone formed between hard opaline crusts on rock surfaces and material not affected strongly by recent exogenic processes. Degraded rock crusts, which may bear parts of the biogenic structures, are present in sandy talus deposits usually representing all of the Holocene. Insect “borings” within lithified substrates in terrestrial settings are an unusual phenomenon; their fossilization potential in the Holocene sediments of the Bohemian castellated rocks may be relatively high.     

Presence of the mosquito Anopheles hyrcanus in South Moravia, Czech Republic

During a survey of mosquitoes in the South Moravian lowland area, the mosquito Anopheles hyrcanus (Pallas) (Diptera: Culicidae) was found breeding in an ancient fishpond (Nesyt). It is not clear whether this southern Palaearctic species, a known vector of malaria in Asia which has not been recorded in the Czech Republic until this year, has gone undetected in the past or whether it has recently moved into the region as a result of climate change.     

New distributional data and an updated and commented list of Czech and Slovak Sarcophagidae (Diptera)

Based on a revision of large recent collections housed by Czech University of Life Sciences Prague, Masaryk University, Brno, and in the private collection of Yu. Verves (Kyiv, Ukraine), new distributional data and an updated and commented list of Czech and Slovak Sarcophagidae are presented. The following six species are firstly recorded from the Czech Republic: Macronychia (s. str.) substriginervis Verves & Khrokalo, 2006, Paragusia multipunctata (Rondani, 1859), Oebalia praeclusa (Pandellé, 1895), Nyctia lugubris (Macquart, 1843), Blaesoxipha dupuisi Léonide & Léonide, 1973, and B. grylloctona Loew, 1861. As a result, 143 species of the family Sarcophagidae are currently known from the Czech Republic (109 from Bohemia and 129 from Moravia), and 131 species are known from Slovakia.