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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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Lower Cretaceous belemnites (including J/K boundary interval) in the NW Tethys, biostratigraphy, palaeobiogeography and palaeoecology
Vaňková, Lucie ; Košťák, Martin (advisor) ; Michalík, Jozef (referee) ; Fozy, István (referee)
This thesis deals with the belemnite fauna from the Outer Western Carpathians Klippen, its systematic classification, stratigraphical and palaeogeographical evaluation. The palaeontological/palaeobiological approach, together with isotope analyses, including of carbon and oxygen stable isotopes and of strontium isotopes, enabled an integrated investigation of the palaeoecological conditions during the Jurassic/Cretaceous (J/K) boundary interval and the Early Cretaceous age. The Tethyan belemnites are not intensively studied in detail in the J/K interval, as they occur rather rarely in the sections, and/or sedimentary conditions were not suitable for their preservation. Therefore, belemnites are described only from a few sites in the Mediterranean Province. On the basis of recent research, the stratigraphic range of several species previously considered to be from the Tithonian age was extended to the earliest Cretaceous. By contrast, the Lower Cretaceous belemnites (since the late Berriasian) are more abundant. In the classical areas of the Tethyan Realm, it is possible to study the Lower Cretaceous belemnites in great detail and, according to their higher abundance, to determine an individual assemblage corresponding to stratigraphical intervals. Their occurrence is also an important basement for...
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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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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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