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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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Echinoids, their evolution and response to the Cretaceous paleoenvironmental events
Hedánková, Karolína ; Košťák, Martin (advisor) ; Nohejlová, Martina (referee)
The bachelor thesis briefly summarizes knowledges about the evolution of sea urchins (Echinoidea; Echinodermata) with a focus on the successful order Spatangoida and their diversification in the dynamic Mesozoic environment. Attention is paid in particular to significant palaeoceanic changes, such as anoxic events (OAE = Oceanic Anoxic Event) and extinctions. Responses to OAE1-OAE3, as well as the last mass extinction (within the "Big Five") at the Cretaceous-Paleogene (K-Pg) boundary, are briefly discussed. Sea urchins, as an important part of benthic communities, prove to be a suitable model group not only for understanding the dynamics of evolution, but also successful strategies for surviving crisis events and new adaptations. Key words: Mesozoic, echinoids, evolution, events
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Crustacea (Decapoda, Cirripedia) from the Bohemian Cretaceous Basin
Kočová Veselská, Martina ; Košťák, Martin (advisor) ; Krobicki, Michal (referee) ; Schweigert, Guenter (referee)
This thesis deals with systematic revision, evolutionary trends, palaeoecology and migration patterns of crustaceans (Cirripedia and Decapoda) from the Upper Cretaceous of the Bohemian Cretaceous Basin. Thesis is presented as a compilation of 9 papers that were published in scientific peer-reviewed journals and includes not only old museum material, but also numerous crustacean specimens which have been recovered in the last decade. Besides, short remarks on fossil crustaceans currently under study or in the process of being published (Paraclythia, Oncopareia, Acrothoracica) are also included in this thesis. In view of the fact that the fossil crustaceans from the BCB were most recently recorded in the turn of the 19th and the 20th centuries (and partially revised in the first half of the 20th century) and since the systematics and taxonomy have changed significantly, all papers presented here focus primarily on systematic revision and modern description. The essential part of the thesis thus deals with taphonomy and its bearing on the identification of fossil material. Thanks to a modern description, new species of Ctenocheles fritschi (axiidean shrimp), Archaeochionelasmus nekvasilovae (acorn barnacle), Myolepas reussi and Capitulum sklenari (pedunculate barnacles) were erected. C. fritschi is...
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Problems of the K/T boudary
Pícha, Štěpán ; Košťák, Martin (advisor) ; Holcová, Katarína (referee)
Mass extinction attracts the attention of scientists for a long time. Particularly examined in detail the extinction at the Cretaceous/Tertiary boundary, took place from 65.9 + -0.4 millionyears. There are numerous theories which try to explain the causes that led to the youngest of the five major extinctions in Earth history. Since 1980, when the iridium anomaly has been recorded in sediments , the theory of extraterrestrial cause of the extinctions caused by meteorite or comet was introducet. This theory has partly been confirmed by the findings impact crater in the Gulf of Mexico. Further examination, however, proved that the crater quite significantly precedes the boundary. Attention therefore has turned in another direction,i . e. the terrestrial cause of extinction. More recent scientists pay attention to present-day India and huge volcanic traps that created the Deccan platform.During the examination of the Deccan traps, the unexpected an impact crater structure, which is several times larger than the crater in the Gulf of Mexico, has been discovered This discovery started anew dispute about the main cause of the extinction at the Cretaceous / Tertiary boundary. Based on modern literature, the three major theories of the K/T extinction are discussed. I have tried to focus their causes,...
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Ammonites of the geslinianum zone, Upper Cenomanian (BCB)
Cápová, Andrea ; Košťák, Martin (advisor) ; Ziegler, Václav (referee)
ENGLISH SUMMARY Ammonite assemblage from the Upper Cenomanian of the Bohemian Cretaceous Basin realtively poorly known. Some species have been described herein for the first time: Thomelites cf. sornayi (Thomel) Euomphaloceras septemseriatum (Cragin) Eucalycoceras pentagonum (Gragin) and Allocrioceras annulatum (Shumard.). These records predominantly come from the M. geslinianum zone sediments developed in the higher parts of the Pecinov member (Uličný et al., 1998) of the Peruc - Korycany Formation. The sediments yielding ammonite assemblage represents the Late Cenomanian transgressive tract, accompanied by anoxic event OAE II = Oceanic anoxic Event II, CTBE) worldwide recorded in sediments and showing an increased content of stable isotope δ13 C. The OAE II is suggested to be connected to marine biota crisis and also the mass extinctionas well. The most affected organisms were benthic forms, due to high anoxic conditions at the bottom of the water column. Morphological features of the shells may, depending on the quality preservation shells (or cores) can be used to paleobathymetric interpretations. Most described species lived at depths of 50-80 m (up to 100m). Pelagic ammonites (i.e. Sciponoceras) lived at depths of up to 50 m. Heteromorphic taxa (Allocrioceras) have occurred at a depth of up to 100 m.
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Cephalopods and biostratigraphy of North Bohemian Jurassic sediments
Hrbek, Jan ; Košťák, Martin (advisor) ; Ziegler, Václav (referee)
The Jurassic ammonites from the Northern Bohemia has been revised on the base of the material stored in the National Museum in Prague and the Faculty of Science, Charles University in Prague. 23 species and 19 genera, belonging to 7 families were described on the basis of this systematical revision. This ammonite assemblage indicates a proportional occurence of the Boreal, Tethyan and also cosmopolitan taxa. Stratigraphically important taxa suggest a considerably longer period of sedimentation, predominantly represented by the Upper Jurassic carbonates. This interval may contain up to 9 ammonite zones. A pilot microfacial analysis of carbonates from Peškova stráň area (in Krásná Lípa vicinity) indicates a considerably higher variability of sedimentation area. The presence of micritic carbonates suggests the existence of a widespread areas in the Late Jurassic sea covering the Bohemian Massif. The biostratigraphy and palaeogeography is briefly discussed in the European Late Jurassic context. Key words: ammonites, Upper Jurassic, Northern Bohemia, carbonate sediments, biostratigraphy, palaeogeography
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Selected cephalopods from the Ordovician of the Prague Basin (Bohemia) and Baltica (Estonia and Sweden): taxonomy, paleobiogeography and paleoecology
Aubrechtová, Martina ; Košťák, Martin (advisor) ; Klug, Christian (referee) ; King, Andrew H. (referee)
This dissertation thesis is a summary of five studies published in peer- reviewed, impacted scientific journals. All of the publications are taxonomic revisions of previously unknown or little known collections of fossil cephalopods from the Early Paleozoic strata of Bohemia, Estonia and Sweden. Paleogeogra- phical and stratigraphical distributions of the respective taxa were summarized, refined and compared with contemporary fossil assemblages known from other regions. Implications on the paleoecology of the cephalopods and original envi- ronmental conditions were made. The text of the thesis is divided into three main parts. In the first part, the morphology of cephalopods is explained, stressing out the most important diagnostic characters used for their descriptions. The current systematics of the Cephalopoda is overviewed and the main cephalopod groups during the Ordovician are briefly introduced. The second part of the thesis describes the geological development and settings of the regions, from which the studied fossil cephalopods originate. The third and final part of the thesis provides a discussion and interpretation of the results of the published studies in the context of the previously published research. The genus Bactroceras Holm, 1898 and some members of the order Litui- tida were studied...
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Rudist assemblages of the Upper Cretaceous "pocket" infills in the Teplice rhyolite - systeamtics, palaeoecology, stratigraphy
Křížová, Barbora ; Košťák, Martin (advisor) ; Čech, Stanislav (referee)
The study (MS, diploma thesis) is based on more than 1500 rudist samples from the Upper Cretaceous sediments of localities Písečný vrch and Na Stínadlech (near Teplice). Investigated samples come mainly from the collection of A. H. Fassel and were collected at the end of the 19th century, currently stored in the Regional museum in Teplice and National museum in Prague. The rudist shells were determined by generic and species levels, including five genera and eight species. The stratigraphic age of both localities has been a subject of discussion since the second half of the 19th century. In the recent decades, the opinion on the lower turonian age prevailed. However, five of the eight species present in the studied localities demonstrate the upper cenomanian age of the assemblages, making them probably the oldest known rudist-corals assemblages of its kind. The palaeoecological analysis and the ecological relationships proposal for the studied localities is based on the research in literature on palaeoecology and evolution of the rudists, also presented in the study. Key words: Bohemian Cretaceous Basin, Cenomanian - Turonian, rudists, corals, palaeoenvironment, Teplice rhyolite
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Lower Cretaceous belemnites and their occurrence in Czech Republic
Vaňková, Lucie ; Košťák, Martin (advisor) ; Marek, Jaroslav (referee)
The thesis deals with an complex overview of the Lower Cretaceous belemnites, and their occurrence in the Czech Republic, especially in Štramberk locality. First part provides a brief introduction to the Lower Cretaceous and to belemnite morfology with emphasis on internal skeleton especially of rostrum. Next chapter includes short review of morfometric analysis, which is the most important feature for taxonomy. The following part presents systematics and taxonomy of the Lower Cretaceous belemnite, and their paleoecological use as an indicators for paleotemperatures. There are also mentioned geographical occurrences and migrations of certain belemnite taxa and their stratigraphical evidence in the Lower Cretaceous sediments. The last part deals with the locality Štramberk, which is unique in the Czech Republic because of its stratigraphical evidence of the Lower Cretaceous belemnite fauna. Key words: Belemnites, Lower Cretaceous, systematice, palaeobiogeography, palaeoecology, Štramberk
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