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Association of Turonian echinoids at the Nebužely locality (Bohemian Cretaceous Basin)
Bartušková, Nikola ; Fatka, Oldřich (advisor) ; Ziegler, Václav (referee)
This diploma thesis is focused on morphological studies and taxonomic analyses of small regular and irregular echinoids found at the Nebužely locality; at this locality clastic sediments of Teplice Formation of Bohemian Cretaceous Basin are exposed. Presence of the belemnite Praeaxtinocamax bohemicus makes possible to assign the outcrop to late Turonian. Detailed morphological study of more than one hundred specimens enabled to distinguish four echinoids species (Echinogalerus, Glyphocyphus, Nucleolites, Phymosoma), less favourably preserved and/or very limited material is classified as belonging to two orders (Cidaroida, Holectypoida) and one family (Phymosomatidae), respectively. The next part of the thesis contains a possible palaeoecological reconstruction of the environment at the studied locality. Based on bathymetrically indicative molluscs, a shallow−water palaeoenvironment is suspected for this locality. Key words: echinoid, Bohemian Cretaceous Basin, Turonian
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Macroevolutionary and ecological implications of the theory of frozen plasticity
Toman, Jan ; Flegr, Jaroslav (advisor) ; Fatka, Oldřich (referee) ; Mikuláš, Radek (referee)
The frozen plasticity theory is a punctuationalist theory of adaptive evolution. It states that long periods of stasis, during which populations respond to selection pressures only by elastic change in the frequency of already present alleles, alternate in the evolution of sexual species with short periods of plastic evolution, during which alleles can get fixed or eliminated by directed selection. Asexual species are not expected to maintain such high genetic polymorphism in the long term. They should, however, be able to plastically respond to selection pressures throughout their whole existence. This difference between the evolutionary dynamics of sexual and asexual clades has a number of ecological and macroevolutionary implications. Concerning ecology, we could expect different environmental preferences of sexual and asexual species. Accordingly, in our first work that was based on a comparative study, we statistically significantly supported the hypothesis that (ancient) asexual groups of (eukaryotes) inhabit more stable and homogeneous habitats than their related sexual controls. Focusing on actually experienced, i.e. subjective, heterogeneity of the environment turned out to be the crucial factor of this type of research. From the viewpoint of macroevolutionary implications of the frozen...
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"Small carbonaceous fossils (SCFs)": state of art
Kovář, Vojtěch ; Fatka, Oldřich (advisor) ; Dašková, Jiřina (referee)
The thesis deals with the problematics of Small Carbonaceous Fossils (SCF). In the first part of the thesis the term SCF is defined and the presentation of the main palynological approaches used for extraction of SCFs follows, together with an explanation of preservation processes of non-biomineralized organic structures in sediments. The explanation of significance for palaeontology and related disciplines is discussed. The main part of the thesis constitutes of descriptions of the individual published SCFs from the late Ediacaran up to the Devonian, together with stratigraphic context and lithology of the published material. The list of taxa, that were possible to identify among obtained SCF material, is included. All the localities of Phanerozoic age are further plotted into paleogeographic maps corresponding with the appropriate periods. The broad scope of SCF's paleogeographic provenance and the possibility of extraction of SCF from a wide spectrum of lithologies, deposited in various sedimentary environments is discussed and the potential of further studies of SCFs is outlined. Key words: organic microfossils and macrofossils, early Paleozoic, taphonomy, palynological preparation methods
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Eocrinoid echinoderms from mid-Cambrian of the Barrandian area
Nohejlová, Martina ; Fatka, Oldřich (advisor) ; Mergl, Michal (referee) ; Valent, Martin (referee)
This thesis deals with the topic of eocrinoid echinoderms from the Barrandian area (Příbram- Jince Basin, mid-Cambrian, Drumian). The thesis is presented as a compilation of five published papers and an introduction. The introduction is an overview of current knowledge about eocrinoid echinoderms. It also includes links to new information from the five included papers, and serves as a unifying element for these professional publications. The topic of the thesis is focused on a revision of selected specimens of eocrinoid echinoderms, and the study of their ontogeny, phylogeny, palaeoecology and systematic position. This thesis has also improved our understanding of early evolution of basal blastozoans. This is the first study of Cambrian ontogenetic development on eocrinoid material from the Czech Republic. Complete ontogeny was described on the genus Akadocrinus, and it was possible to establish two basic phases in the development of this genus: pre-epispire-bearing phase and epispire-bearing phase. The new primitive blastozoan Felbabkacystis is described from the Jince Formation - its unique body plan highlights evolution of the body wall among blastozoans. Palaeoecology and phylogeny of the genus Vyscystis was studied, and phylogenetic analysis suggests a basal position of lepidocystoids among...
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Morphology of genal caeca in selected trilobites from the Barrandian area
Vyhnánková, Iva ; Fatka, Oldřich (advisor) ; Laibl, Lukáš (referee)
The term "genal caeca" refers to branching and anastomosing ridges developed with varying intensity on free and fixed cheeks and preglabellar field in many trilobites, including the trilobites from Barrandian area of the Czech Republic. This diploma thesis presents the first detailed study of the morphology of genal caeca preserved on cephalons of Cambrian trilobite genera Ptychoparia Hawle & Corda, 1847, Mikaparia Kordule, 2006 and Conocoryphe Hawle & Corda, 1847 from Příbram-Jince and Skryje-Týřovice basins of the Barrandian area. Based on a detailed morphological description and measurements, separate fields of genal caeca occurrence were defined and frequency of their preservation on the studied specimens was compared. The variability of the number of ridges in each field and the frequency of their preservation do not show any convincing connection with cranidial size of the specimens or the locality. Keywords: trilobites, Barrandian area, genal caeca
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Recent knowledge of sea urchins in the Bohemian Cretaceous Basin
Bartušková, Nikola ; Fatka, Oldřich (advisor) ; Vodrážka, Radek (referee)
This thesis is focused on an overview of recent knowledge of sea urchins in the Bohemian Cretaceous Basin. In the first part is a summary of basic information about Bohemian Cretaceous Basin, including chronostratigraphic, lithostratigraphic classification and palaeogeography. The second part of the thesis contains an overview of partial synonymy of echinoids of the given regional - geological unit. Mentioned are also strata, from which are sea urchins described. Key words: sea urchins, Bohemian Cretaceous Basin
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Ontogeny of selected taxa of middle Cambrian trilobites and agnostoids of the Barrandian area
Laibl, Lukáš ; Fatka, Oldřich (advisor) ; Mergl, Michal (referee) ; Edgecombe, Greg (referee)
This thesis deals with the ontogeny of trilobites and agnostids from the Cambrian of the Skryje-Týřovice and Příbram-Jince basins (Barrandian area, Bohemian Massif). Thesis is presented as a compilation of four papers that were published in scientific peer-reviewed journals. The introduction of the thesis serves as a general overview of the trilobite post- embryonic development and connects all published papers together. All four papers presented here are focussed on modern description of the post-embryonic development of Sao hirsuta, Ptychopariida sp. A, Ptychopariida sp. B, Ptychopariida sp. C, Ellipsocephalus hoffi, Ellipsocephalus polytomus, Hydrocephalus carens and Ecca- paradoxides pusillus. In addition, a discussion about the life-history strategies of early developmental trilobite stages is presented. It has been suggested that Sao hirsuta and Ptychopariida sp. A had benthic protaspides and that the early ontogenetic stages of Ptychopariida sp. B, Eccaparadoxides pusillus and Hydrocephalus carens were likely lecithortophic. Consequently, it has been documented that species with benthic protaspides show a strongly restricted geographic distribution and that lecithotrophic taxa seem to be associated with higher latitude areas. The developmental patterns of Ellipsocephalus hoffi and...
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Silurian Scolekodonts of the Barrandian area
Tonarová, Petra ; Fatka, Oldřich (advisor) ; Slavík, Ladislav (referee) ; Michalík, Jozef (referee)
Scolecodonts (= jaws of the polychaete worms) have always been a relatively neglected group of microfossils. In the Prague Basin (Czech Republic), only two major studies exclusively focused on scolecodonts have been published. The aim of the present research was to fill in this gap - by a restudy of the historical collections of Žebera and Šnajdr, and its comparison with results gained from newly collected late Silurian samples and scolecodont faunas from other areas. It has turned out that the jawed polychaete fauna in the Prague Basin was much more diversified than previously reported. The last report on late Silurian scolecodonts by Šnajdr (1951) concluded that there are four determined and two species left in open nomenclature present. Restudy of the original collection has shown that there are at least 11 different species from families Mochtyellidae, Polychaetaspidae, Ramphoprionidae, Paulinitidae, Atraktoprionidae, Skalenoprionidae and Hadoprionidae. The new collection from similar stratigraphical level gained at least 25 species, including one newly described ("Mochtyella" pragensis). The taxonomic re-study also focused on the species Kettnerites kosoviensis that is a type species of the genus and was described in the Prague Basin. The new samples come from the limestone which is in contrast to...
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