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Impact of being evergreen or deciduous on the wood anatomy of the trees in polar regions during the warm geological period : case study from Upper Cretaceous of the James Ross Island (Antarctic Peninsula)
Chernomorets, Oleksandra ; Sakala, Jakub (advisor) ; Gryc, Vladimír (referee)
Global warming and its influence on the environment has become a popular and widespread issue. Nowadays, an analogy of a high latitude ecosystem during the greenhouse type of climate does not exist. The Cretaceous polar ecosystem gave us a unique possibility of understanding these extreme ecosystems and the specific adaptations of organisms to these conditions. Such types of ecosystem are crucial for a better understanding of possible future climate changes. This thesis focusses on the adaptation strategies of land plants during the Late Cretaceous in the Arctic peninsula. The land plants responded to these specific solar conditionals in two different ways: evergreen or deciduous. The fossil material for this study comes from Brandy Bay and Crame Col, James Ross Island, Antarctic. The material was collected in a continuous sequence from Kotic point to Santa Marta Formation (Cenomanian - Companian). A detailed and systematic analysis was performed on five out of fifty-five samples that well represented the studied region and age: Agathoxylon kellerense, Agathoxylon antarcticus, Araucarioxylon chapmanae, Podocarpoxylon multiparenchymatosum and Phoroxylon sp. Based on the detailed study of Agathoxylon kellerense (sample number AN34) wood anatomy and growth rings structure, adaptation strategies were...
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Aspects of the high latitude environments in Cretaceous and Paleogene with special respect to land plants
Chernomorets, Oleksandra ; Sakala, Jakub (advisor) ; Dašková, Jiřina (referee)
This work is focused on the problematics of high latitudes in Cretaceous and Paleogene. The introduction describes and defines high latitude regions as well as their main characteristics nowadays. This allows one to achieve a better understanding of the substantial differences of these regions nowadays and in the geological past. The work itself then provides a brief description of the palaeographic position of the Arctic and Antarctic regions, their palaeoclimatic situations, organisms inhabiting their terrestrial and marine environments and their adaptation mechanisms. Further, a more detailed review of the land plants is presented. The last part is dedicated to the specific survival strategies of the land plants in the polar regions during the warm geological periods. On the basis of the studied literature, this work attempts to answer the questions: which strategy for adaptation to the high latitudes was used by the plants and whether being evergreen or deciduous was more effective on survival during the long and relatively warm polar nights. In conclusion, the relevance of the research of high latitude regions during the Cretaceous and Paleogene greenhouse type of climate is introduced in relation to the possible future consequences of the global warming. Key words: Cretaceous, Paleogene, land...
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Lower Turonian ammonites of the Bohemian Cretaceous Basin: taxonomic synopsis, stratigraphy and palaeoecology
Kohout, Ondřej ; Košťák, Martin (advisor) ; Ziegler, Václav (referee)
This thesis summarizes the findings of lower Turonian ammonites of the Bohemian Cretaceous Basin (BCB). It presents an overview of the most important taxonomic species and their brief morphology and paleoecology. Marginally, it describes sedimentary facies of the BCB which belongs to the lower Turonian ("Bílá Hora" Formation). Part is devoted to determining the stratotype between Cenomanian and Turonian, to the events that occurred during this period (CTBE, OAE II) and their impact on biocoenosis of early Turonian ammonites. This thesis tries to comprehend the importance of ammonites biostratigraphy to define the Lower Turonian and basic ammonites zones, which belongs to this period. Defining stratotype Cenomanian / Turonian has not yet been satisfactorily resolved and this work is the basis for further research and study. Key words: ammonite, Bohemian Cretaceous Basin, biostratigraphy, Turonian, paleoecology
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Autecological study of selected Cretaceous plants using stable Carbon isotopes
Zahajská, Petra ; Kvaček, Jiří (advisor) ; Diefendorf, Aaron (referee)
1 Abstract This thesis presents an analysis of fossil plants from the Cenomanian Peruc-Korycany Formation of the Bohemian Cretaceous Basin and from the Bückeberg Formation of the Lower Saxony Basin in Germany. Based on earlier studies, both areas provide sediments that are considered to have developed in tidally influenced fluvial systems. Studied fossil plants are represented by ginkgoalean plant leaves (Ertemophyllum, Tritaenia), branches of conifers (Frenelopsis) and lauroid angiosperms (Eucalyptolaurus). Frenelopsis, Eretmophyllum and Tritaenia are considered to be halophytic plants, while Lauroid angiosperms were considered to grow in fresh water conditions. The fossil plants were studied using cuticle analysis and two methods of stable carbon isotope analysis: Bulk carbon isotope analysis and Compound Specific Isotope analysis. For cuticle analysis samples were observed and documented macroscopically and microscopically. To specify the environmental conditions, recent samples from three salt marshes in Great Britain were studied and analysed using the same methods as the fossil samples. The data from all observations and measurements were processed and their interpretation supported the modelled environment based on the sedimentological data. Frenelopsis were growing in a haline environment with low...
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Paleoecology of the Turonian Ostracoda from the Úpohlavy section
Houdková, Markéta ; Kyška Pipík, Radovan (advisor) ; Seko, Michal (referee)
This thesis deals with the class Ostracoda from the Úpohlavy quarry, which is an important paleontological site of the Turonian in the Czech Cretaceous Basin with abundant and well- preserved fauna. Twenty samples from marls and limestones of Jizera and Teplice formation were colected in which 36 marine middle and upper Turonian ostracods species were identified. Ostracods of the studied profile are characterized by gradual increase of species richness and decline of dominance of Cytherella cf. ovata (Roemer, 1840). The lowest diversity is in the Jizera formation and the highest diversity in the Teplice formation. The order Platycopida prevails on the order Podocopida in the Jizera formation, in which percentages of Platycopida is in the range 67-89%, while its percentage in the Teplice formatiion is lower in the range 25-59 %. Using the Platycopida Signal Hypothesis in a sense of Whatley et al. (2003), which compares percentages of Platycopida and Podocopida, a low O2 content in Jizera formation and in the Coprolite bed (monotonous dark marls) of Teplice formation is supposed. This is in accordance with low number of species (5-11 per sample) and with higher TOC content (0.34-0.74 %). With the beginning of limestone and marl sedimentation of the Teplice formation a number of species increases...
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Ostracods from the Czech Creatacous Basin - current state of knowledge and revision of prof. Pokorny collection
Houdková, Markéta ; Pipík, Radovan (advisor) ; Seko, Michal (referee)
The class Ostracoda is a group of microfossils, which is important in cases where other leading fossils are missing. In the paleontological record Ostracods show ecological and paleogeographic conditions or may help determine the age of the sediment. Professor Vladimír Pokorný dealt with Ostracods in the Czech Cretaceous Basin. The main result of this work is a summary of his articles about that. The subclass Podocopa is the most common group. For ostracod determination is necessary detailed knowledge of the morphology and ornamentation of the carapace, so part of the work is about these characters. Key words: Ostracoda, Cretaceous, Czech Cretaceous Basin
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Paleomagnetism and magnetomineralogy of rocks from the Bohemian Massif and Tethyan Realm
Schnabl, Petr ; Pruner, Petr (advisor) ; Hrouda, František (referee) ; Petrovský, Eduard (referee)
Mgr. Petr Schnabl - Dissertation Paleomagnetism and magnetomineralogy of rocks from the Bohemian Massif and Tethyan Realm Abstract The thesis deals with paleomagnetic and rock magnetic properties of Silurian/Devonian and Jurassic/Cretaceous limestones, Paleogene/Neogene basaltic rocks and altered Silurian basalts. The main goal is to determine the history of the Earths' magnetic field from the Silurian to the present. Two lithostratigraphic formations are defined in the Jičín volcanic field on the basis of volcanology, paleomagnetism and radiometric dating. The Trosky Formation (24.6?/18.3 - 15.7 Ma) is composed of several Strombolian-type volcanoes, while the Kozákov Formation (5.2 - 4.6 Ma) is represented by effusive products with a crater vent of a single giant volcano. One Pliocene (4.3-3.3 Ma) and two Pleistocene phases (2.6 -2.1 Ma and 1.8 - 1.1 Ma) of volcanic activity Magnetostratigraphy is a very important tool for the definition of the J/K boundary. The boundary between the Crassicolaria and Calpionella zones is present within geopolarity zone M19n. The boundary between the ammonite zones Jacobi and Durangites also lies close to this point. Paleomagnetic directions of Silurian and Devonian rocks in the Bohemian Massif are very difficult to interpret and have been studied as a challenging problem...
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Cretaceous Foraminifera from the Březno section
Hašková, Barbora ; Holcová, Katarína (advisor) ; Tomanová, Pavla (referee)
Thesis is focused on foraminifera from classical Březno section. It describes the basic charakteristics of foraminifera, Czech Cretaceous Basin, Březno section near Louny and history of research of Cretaceous foraminifera in Czech Republic. Taxonomically studied planktonic foraminifera species are from family Heterohelicidae Cushman, 1927, and benthos species are from family Lagenidae Reuss, 1862, Nodosariidae Ehrenberg, 1838, and Vaginulinidae Reuss, 1860. Key words: Foraminifera, Cretaceous, Březno near Louny, Heterohelicidae, Lagenidae, Nodosariidae, Vaginulinidae
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Cretaceous Radiolaria from the Březno section
Müllerová, Petra ; Holcová, Katarína (advisor) ; Vajskebrová, Markéta (referee)
The presented thesis is focused on the Radiolaria of the Czech Cretaceous Basin. The studied material was collected in Březno u Loun and in the Úpohlavy quarry. Biology, ecology and morphology, as well as systematics of the whole group is discussed. An important part of this thesis constitutes of the geological settings of Cretaceous, Czech Cretaceous Basin and both localities. 26 samples from Březno and 24 samples from the Úpohlavy quarry have been studied using several methods with the aim to obtain most numerous and best preserved communities possible. Despite poor preservation of the shells, 9 species have been identified. Several shells have been assigned at least to the genus or order levels. Species of Dictyomitra communis (Squinabol, 1904), Dictyomitra cf. napaensis Pessagno, 1976, Turbocapsula cf. giennensis O'Dogherty, 1994, Novixitus cf. mclaughlini Pessagno, 1977, Stichomitra cf. stocki (Campbell & Clark, 1944), Stichomitra communis Squinabol, 1903, Stichomitra japonica (Nakaseko & Nishimura), in Nakaseko et. al., 1979, Holocryptocanium barbui Dumitrica, 1970, cf. Pseudoaulophacus pargueraensis Pessagno, 1963 and genera of Orbiculiforma, Stichomitra, cf. Cryptamphorella have been reported in the Czech Cretaceous Basin for the first time.
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