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Palaeoecological aspects and evolution of the Late Cretaceous oyster assemblages
Rantuch, Jakub ; Košťák, Martin (advisor) ; Mergl, Michal (referee) ; Reháková, Daniela (referee)
The presented thesis explores the palaeoecological aspects of the evolution of the well-known fossil oyster genus Rhynchostreon Bayle, 1874, a significant representative of Cretaceous fauna. The study integrates sedimentological (quartz grain size), geochemical (concentration of major oxides) and palaeobiological (taphonomy) proxies to categorise five oyster-bearing localities in the Bohemian Massif and the Pieniny Klippen Belt (Western Carpathians) into three environments with differing substrate characteristics, environmental energy levels and salinity regimes. Subsequently, the five specific palaeopopulations of Rhynchostreon suborbiculatum (Lamarck, 1801), occupying these habitats (including the dynamic Cenomanian nearshore, the quiet environment of the Turonian hemipelagic sea and the Cenomanian-Turonian marginal marine system influenced by variable fluvial activity), underwent a series of morphological and population studies. These studies involved the analyses of size-frequency distributions, morphotype structure, and shell thickness. Results from this multidisciplinary approach suggest that the salinity tolerance of R. suborbiculatum may be higher than commonly assumed, and its ecological response to climatic changes (i.e. the fluctuation of salinity, level of eutrophism, etc.) aligns with...
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Foraminifera of the Bohemian Cretaceous Basin
Hašková, Barbora ; Holcová, Katarína (advisor) ; Frank, Jiří (referee)
The thesis deals in the compilation part with systematic classification, biology, morphology of the test, ecology and palaeoecology of the Foraminifera. Next research focuses on the history of Cretaceous Foraminifera in our area and the geology of the Bohemian Cretaceous Basin, focusing on Úpohlavy site in the northwestern part of the Bohemian Cretaceous Basin. Three samples from Úpohlavy section were preliminary micropaleontologically analysed. Plankton / bentos ratio was counted. Genus Heterohelix and Planoheterohelix was described and taxonomically studied. Keywords: Upper Cretaceous, Bohemian Cretaceous Basin, Foraminifera, Heterohelix 1
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Planktonic ecosystems of the Upper Jurassic and Cretaceous (calcareous nannoplankton, calpionellids)
Svobodová, Andrea ; Holcová, Katarína (advisor) ; Skupien, Petr (referee) ; Oszczypko-Ciowes, Marta (referee)
The presented PhD thesis is compiled as a commentary to four published papers, which deal with planktonic assamblages of the Upper Jurassic and Cretaceous, namely with calcareous nannofossils and calpionellids. The first part of the dissertation thesis describes the main characteristics of the studied fossil groups with focus on their morphology, palaeoecology, evolution and systematics. The chapter of calcareous nannoplankton gives special attention to the biostratigraphicaly important genus Nannoconus Kampter 1931. Next chapters describe the methods of the laboratory processing of the sediments and the geological settings of the studied areas. The thesis is focused on two areas. At first the selected localities in the Bohemian Cretaceous Basin, i.e. Upper Turonian and Upper Coniacian, are described. Generally, the Upper Cretaceous platform sediments of the middle European basins are rich in calcareous nannoplankton. These fossils represent important marker for biostratigraphical and palaeoecological interpretations. The second part describes carbonate rocks of the Upper Jurassic and Lower Cretaceous of the Tethyan area. In this case, calcareous nannoplankton and calpionellids are an essential part of the modern multidisciplinary form of the Jurassic- Cretaceous (J/K) boundary interval research....
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Facies and architecture analysis of the continental deposits of Klikov Formation, Hosín-Orty locality, Upper Cretaceous, České Budějovice Basin.
Kavková, Radana ; Martínek, Karel (advisor) ; Lojka, Richard (referee)
The Klikov Formation (Upper Cretaceous) represents the lowest stratigraphic unit of the South Bohemian basins. It provides record of continental deposits related to fluvial processes. Analysis of facies and architectures supplemented with paleocurrents data provided a basis for interpretation of depositional system exposed underground on the locality Hosín-Orty. In this study identifies sedimentary facies corresponding to high-energy river environmnent with dominance of traction current deposition are identified. Next to this, facies corresponding to low-energy deposition from suspension is preserved. From the perspective of architecture analysis depositional record represent active river channels and their fills eventuelly fills of abandoned channels. Low dispersion of paleocurrent values is consistent with a low-sinuosity river. Vertical aggradation of channels, dominance of river bars in channel-fill, downstream accretion, absence of ripples, point-bars, lateraly accreted patterns and floodplain deposits correspond with braided river environment. Stratigraphic units A, B, C, D, E, F corresponding to fluvial environment or environment of abandoned channel were distinguished. The direction of river flow is interpreted to northeast in unit A, and northwest in unit B, respectively. Autogenic and...
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Nautiloidea of Upper Cretaceous epicontinental seas in Europe
Frank, Jiří
The post-Triassic Nautiloidea are not as popular theme within fossils cephalopods research as for example ammonites. They are not very abundant in the fossil records except some rare localities and areas, their morphology is quite conservative and due to the usually poor preservation, their determination and assigning to the species even to genera level is often complicated. Exceptional are taxa with very specific morphology and short stratigraphic and endemic occurrence, which are even suitable for biostratigraphic interpretations. Problematic is also the often poor taxonomical representation of the type material and revision of many taxa is needed. Still nautilids are often represented by reasonable amount in the paleontological collections of natural history museums due to the long history of fossils collecting. Also the scientific literature has been dedicating at least some space to this group since 19 century. The aim of this study is to create an overview about the post- Triassic, especially Upper Cretaceous nautiolidea in the European region of epicontinental seas and prepare a good basement for extensive study of this group. Due to this aim the study is primarily focused on determination of morphological features and also problematic with their interpretation according to the variable...
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Planktonic ecosystems of the Upper Jurassic and Cretaceous (calcareous nannoplankton, calpionellids)
Svobodová, Andrea ; Holcová, Katarína (advisor) ; Skupien, Petr (referee) ; Oszczypko-Ciowes, Marta (referee)
The presented PhD thesis is compiled as a commentary to four published papers, which deal with planktonic assamblages of the Upper Jurassic and Cretaceous, namely with calcareous nannofossils and calpionellids. The first part of the dissertation thesis describes the main characteristics of the studied fossil groups with focus on their morphology, palaeoecology, evolution and systematics. The chapter of calcareous nannoplankton gives special attention to the biostratigraphicaly important genus Nannoconus Kampter 1931. Next chapters describe the methods of the laboratory processing of the sediments and the geological settings of the studied areas. The thesis is focused on two areas. At first the selected localities in the Bohemian Cretaceous Basin, i.e. Upper Turonian and Upper Coniacian, are described. Generally, the Upper Cretaceous platform sediments of the middle European basins are rich in calcareous nannoplankton. These fossils represent important marker for biostratigraphical and palaeoecological interpretations. The second part describes carbonate rocks of the Upper Jurassic and Lower Cretaceous of the Tethyan area. In this case, calcareous nannoplankton and calpionellids are an essential part of the modern multidisciplinary form of the Jurassic- Cretaceous (J/K) boundary interval research....
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Facies and architecture analysis of the continental deposits of Klikov Formation, Hosín-Orty locality, Upper Cretaceous, České Budějovice Basin.
Kavková, Radana ; Martínek, Karel (advisor) ; Lojka, Richard (referee)
The Klikov Formation (Upper Cretaceous) represents the lowest stratigraphic unit of the South Bohemian basins. It provides record of continental deposits related to fluvial processes. Analysis of facies and architectures supplemented with paleocurrents data provided a basis for interpretation of depositional system exposed underground on the locality Hosín-Orty. In this study identifies sedimentary facies corresponding to high-energy river environmnent with dominance of traction current deposition are identified. Next to this, facies corresponding to low-energy deposition from suspension is preserved. From the perspective of architecture analysis depositional record represent active river channels and their fills eventuelly fills of abandoned channels. Low dispersion of paleocurrent values is consistent with a low-sinuosity river. Vertical aggradation of channels, dominance of river bars in channel-fill, downstream accretion, absence of ripples, point-bars, lateraly accreted patterns and floodplain deposits correspond with braided river environment. Stratigraphic units A, B, C, D, E, F corresponding to fluvial environment or environment of abandoned channel were distinguished. The direction of river flow is interpreted to northeast in unit A, and northwest in unit B, respectively. Autogenic and...
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Nautiloidea of Upper Cretaceous epicontinental seas in Europe
Frank, Jiří
The post-Triassic Nautiloidea are not as popular theme within fossils cephalopods research as for example ammonites. They are not very abundant in the fossil records except some rare localities and areas, their morphology is quite conservative and due to the usually poor preservation, their determination and assigning to the species even to genera level is often complicated. Exceptional are taxa with very specific morphology and short stratigraphic and endemic occurrence, which are even suitable for biostratigraphic interpretations. Problematic is also the often poor taxonomical representation of the type material and revision of many taxa is needed. Still nautilids are often represented by reasonable amount in the paleontological collections of natural history museums due to the long history of fossils collecting. Also the scientific literature has been dedicating at least some space to this group since 19 century. The aim of this study is to create an overview about the post- Triassic, especially Upper Cretaceous nautiolidea in the European region of epicontinental seas and prepare a good basement for extensive study of this group. Due to this aim the study is primarily focused on determination of morphological features and also problematic with their interpretation according to the variable...
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Nautiloidea of Upper Cretaceous epicontinental seas in Europe
Frank, Jiří ; Košťák, Martin (advisor) ; Turek, Vojtěch (referee) ; Schlögl, Ján (referee)
The post-Triassic Nautiloidea are not as popular theme within fossils cephalopods research as for example ammonites. They are not very abundant in the fossil records except some rare localities and areas, their morphology is quite conservative and due to the usually poor preservation, their determination and assigning to the species even to genera level is often complicated. Exceptional are taxa with very specific morphology and short stratigraphic and endemic occurrence, which are even suitable for biostratigraphic interpretations. Problematic is also the often poor taxonomical representation of the type material and revision of many taxa is needed. Still nautilids are often represented by reasonable amount in the paleontological collections of natural history museums due to the long history of fossils collecting. Also the scientific literature has been dedicating at least some space to this group since 19 century. The aim of this study is to create an overview about the post- Triassic, especially Upper Cretaceous nautiolidea in the European region of epicontinental seas and prepare a good basement for extensive study of this group. Due to this aim the study is primarily focused on determination of morphological features and also problematic with their interpretation according to the variable...
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Brachiopoda and polychaeta in Taphocenoses of the Bohemian Cretaceous Basis
Sklenář, Jan ; Košťák, Martin (advisor) ; Michalík, Jozef (referee) ; Vašíček, Zdeněk (referee)
The sesile suspension feeders of Brachiopoda and Polychaeta phyla are relatively well represented in the Bohemian Cretaceous Basin (BCB), and show significant diversity. All three subphyla of Brachiopoda (Linguliformea, Craniiformea and Rhynchonelliformea) are present in the fossil record of the sedimentary basin infill; from Polychaeta, there has hith- erto been evidence of only the Canalipalpata subclass members that created solid, usually carbonatic tubes. In both abundancy and diversity, the most richest associations of fossil brachiopods and polychaets occure in near-shore facies of the Cenomanian to the Lower Turonian, and hemipelagic facies of the Late Turonian age. Prior research, as shows the literature survey given by the author, has been focused mainly on representatives of both groups of near-shore facies origin. The aim of this thesis is to fill in the existing gaps in our understanding of these groups within the BCB. This objective is accomplished in the form of a series of studies (Sklenář & Simon 2009, Vodrážka & al. 2009, Sklenář & al., in press) elaborating the following topics in detail: (A) taxonomy, distribution, morphology, variabil- ity, evolutionary relationships and stratigraphic significance of cancellothyrid brachiopod Gyrosoria abundant in the Middle and particularly in...
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