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Ontogeny of trilobites
Laibl, Lukáš ; Fatka, Oldřich (advisor) ; Budil, Petr (referee)
The thesis summarizes the current state of knowledge about the ontogeny of trilobites. The introductory chapters describe the basic morphology and anatomy of trilobites, and also mention their ecology, occurrence and feeding habits. In the main part of my thesis, I first summarized the existing research in this area, and also dealt in detail with methods of preservation of trilobite larvae, their reproduction, growth, embryology, postembryonal development, segmentation and ecology. I also mentioned the possible usage of this knowledge in other fields (stratigraphy, biogeography, etc.). The last section is a contemporary view on the systematics of trilobites and their position within the Arthropoda.
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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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Ordovician and Silurian chitinozoa from the Prague and Welsh basins: the impact of chitinozoan biology and ecology on biostratigraphic applications
Vodička, Jakub ; Fatka, Oldřich (advisor) ; Verniers, Jacques (referee) ; Miller, Merrell (referee) ; Meidla, Tõnu (referee)
Chitinozoans have a great potential for biostratigraphic correlation of Ordovician through to Devonian marine sedimentary sequences. However, the question of chitinozoan biological affinities remains unresolved. Consequently, also the question of their palaeoecology and mode of life is a matter of discussion. Incorrect interpretation of both these questions can influence the accuracy of chitinozoan-based correlation. Four peer-review studies dealing with chitinozoan biostratigraphy, paleoecology and biological affinities are presented in this thesis. Studied chitinozoan material originated from two areas, the Prague Basin (Czech Republic) and the Welsh Basin (U.K.). Exceptionally preserved chitinozoan clusters with parallel oriented vesicles have been described from the Ordovician rocks of the Welsh and the Prague basins. These clusters have been termed P-clusters and interpreted as remains of an egg mass and support the interpretation of chitinozoans as eggs of unknown metazoans, the chitinozoophorans. The material figured in previous contributions proves the presence of P-clusters in all three chitinozoan families, spanning from the Ordovician to the Devonian and across the palaeo-globe. The P-clusters indicate that a benthic phase must have been included in the chitinozoan spreading cycle....
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Review of phyllocarid crustacenas of the Barrandian area
Šilinger, Matěj ; Fatka, Oldřich (advisor) ; Budil, Petr (referee)
The thesis summarizes the actual knowledge about classification and stratigraphic distribution of phyllocarid crustaceans in Ordovician to Devonian sediments of the Barrandian area. The thesis includes revision of systematic position and classification of individual taxa, mainly on the basis of data and observations published outside of the Czech Republic. The photographic documentation of selected specimens housed in institutional collections is newly provided.
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SCF in Lower Palaeozoic sediments of the Barrandian area
Kovář, Vojtěch ; Fatka, Oldřich (advisor) ; Brocke, Rainer (referee)
1 Abstract In recent years, the term small carbonaceous fossils (SCFs) has been established to accomodate fragile organic-walled fossils of micro- to mesoscopic size that are usually extracted by means of the 'low-manipulation HF extraction' method. This method has so far only been utilized by several authors and no reports have been published on the usage of the method on samples from the Barrandian area. To test the applicability of the method, samples from the Barrandian area were processed. The samples came from eleven localities representing six stratigraphic units (Paseky Shale, Jince Formation, Letná Formation, Kosov Formation, Daleje Shale and Roblín Member). All the units have been studied before by 'standard' methods of palynological processing. Various previously unreported fossils are described, including wiwaxiid sclerites, putative chaetognath remains and acritarch clusters. Furthermore, it is discovered, that the 'low-manipulation HF extraction' can also be used for extraction of originally calcareous fossils. The pilot study provides a further proof that the 'low-manipulation HF extraction' is a useful tool with the potential to significantly expand our knowledge of fossil assemblages. Key words: Small carbonaceous fossils, Cambrian, Ordovician, Devonian, Barrandian area
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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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