|
|
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...
|
|
|
Vertebrates of the Lower Palaeozoic from the Barrandian area (Bohemian Massif) and their comparison with faunas of adjacent areas
Vaškaninová, Valéria ; Kraft, Petr (advisor) ; Přikryl, Tomáš (referee) ; Trinajstic, Kate (referee)
This thesis deals with early vertebrate fossil remains from the Lower Palaeozoic strata of the Barrandian area (Bohemian Massif). It is presented as a compilation of four papers that were published or submitted in scientific peer-reviewed journals with impact factor. All included papers are focused on the most abundant and diverse vertebrate fauna from the Barrandian area - the placoderms. Placodermi are early vertebrates characterized by articulated head and trunk shields composed of dermal bony plates. In the Barrandian area, they occur exclusively in the Devonian of the Prague Basin. The main objectives of the thesis are modern taxonomic revisions of the placoderm taxa from the Prague Basin as well as discussions about trends in their abundance, diversity, and distribution in space and time, taphonomy, and the evolutionary and phylogenetic implications of their morphology. Two characteristic placoderm associations were distinguished. In the Lochkovian and Pragian, members of the group Acanthothoraci dominate the placoderm record. Acanthothoracid placoderms are among the most basal jawed vertebrates and thus a detailed study of their morphology has a great potential to illuminate the relationships and evolutionary patterns among the stem jawed vertebrates. They are most abundant in the...
|
|
|
Silurian and Devonian volcanism of the Prague Basin
Tasáryová, Zuzana ; Frýda, Jiří (advisor) ; Renno, Axel D. (referee) ; Awdankiewicz, Marek (referee)
The principal goal of the thesis is to constrain nature of magmatic and alteration processes, character of mantle source(s), geotectonic setting and palaeogeographic implications of the Silurian and Devonian volcanism in Prague Basin (Teplá-Barrandian Unit, Bohemian Massif). The thesis is based on extensive geochemical study covering major- and trace-element geochemistry, neodymium isotope geochemistry and mineral chemistry supported by petrographic and field observations. The most important conclusions of the thesis are as follows: 1. The Silurian volcanic rocks of the Prague Basin represent within-plate, transitional alkali to tholeiitic basalts, which erupted in continental rift setting through thick Cadomian crust. The basalts originated by low degrees of partial melting of garnet peridotite mantle source. Older Wenlock basalts are similar to alkaline ocean island basalts (OIB) derived from subcontinental lithospheric mantle (SCLM), enriched most probably by frozen pods of Ordovician magmas. Younger Ludlow basalts resemble tholeiitic enriched mid-oceanic ridge basalts (EMORB) derived from subduction-modified SCLM depleted by Late Cambrian melting. The Wenlock-Ludlow melting is characterized by contemporaneous mixing of melts derived from both enriched and depleted SCLM mantle domains. 2....
|
|
|
Taxonomy, ecology and palaeogeographical significance of the genus Euorthisima (Brachiopoda) in the Prague Basin
Bartošová, Kateřina ; Mergl, Michal (advisor) ; Sklenář, Jan (referee)
Taxonomic position of the brachiopod genus Euorthisina HAVLÍ EK 1950 from the Ordovician of the Prague Basin (Czech republic) was subjected to wide discussions and disputes in the past. The genus was first classified within the superfamily Syntrophiiacea (order Pentamerida). Later, a separate family Euorthisinidae by Havlí ek (1977) was defined. At present, the family is assigned to the order Orthida and includes genera Euorthisina HAVLÍ EK, 1950, Lesserorthis BENEDETTO, 2007, Notorthisina HAVLÍ EK & BRANISA, 1980 and Protorthisina BENEDETTO, 2007. In this thesis, a revision of genus Euorthisina HAVLÍ EK 1950 with emphasis on taxonomic classification, palaeoecology and palaeogeographic occurrence of species E. moesta and E. minor described from the Ordovician of the Prague Basin has been made. Klí ová slova: Euorthisina, brachiopoda, Ordovician, Prague Basin, Czech republic.
|
|
|
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...
|
|
|
Latest Ludlow chitinozoans from the Prague Basin: significanec for correlations and succession during Kozlowskii/Lau extinction events
Vodička, Jakub ; Fatka, Oldřich (advisor) ; Štorch, Petr (referee)
Two sections, Všeradice and Kosov, represent continuous sedimentary succession situated in the Prague Basin. No detailed research on stratigraphical level equal the N. kozlowskii graptolite zone focusing on chitinozoans, has not yet been conducted in the Prague Basin and is also very scarce globally. Limestone beds, examined for chitinozoans, were not very productive. Chitinozoan reaction on extinction is visible, if we compile data from both sections. The pre-extinct chitinozoan fauna is characterized by the Conochitinidae family. Samples from the post-extinct interval contained no chitinozoas. The interval of fauna recovery is characterized mainly by the Eisenackitina genera. In this interval, global zone for the uppermost Ludfordian, represented by E. barrandei, can be confirmed. In agreement with all the published literature, we have not found E. philipi, index taxa of the former global zone in the Prague Basin. E. lagenomorpha appears stratigraphically only slightly below E. barrandei and therefore it cannot substitute E. philipi, as it is used in Baltika region. chitinozoa, Prague Basin, Kozlowskii, Lau, extinction, Ludfordian, stratigraphy
|
|
|
Tests of selected methods leading to precise stratigraphy of the Králův Dvůr Formation
Bartošová, Jarmila ; Kraft, Petr (advisor) ; Frýda, Jiří (referee)
A model study about the precise stratigraphy of the Kralodvorian Formation was made on the drill core from Ořech near Prague. The exposure at Levín was used as a reference section. Both sections were sedimentologicaly studied and described in detail. The study of thin sections was a supplemented for exact description of the rocks and lithotypes. Chemostratigraphic methods (?13C and TOC) and method of the rock magnetic susceptibility were used for detailed stratigraphic analyse. All the mentioned methods of both sections. Samples for the measurements of the magnetic susceptibility were taken by 0.5 m of thickness. The measurement of ?13C and TOC was taken from the non-wheathered 80 m of the drill core Ořech and from the upper 20 m Králův Dvůr Formation at Levín profile by 2 m. The available data show that Ořech represents low and middle part of the Kralodvorian strata and that all studied thickness (80 m) belongs to only positive excursion of ?13C. This excursion is interpreted to be the upper Katian. It gives an evidence that sedimentation of the Kralův Dvůr Formation was very fast. Identification and interpretation of this excursion makes possible the accurate interregional corelation of the strata. A precise regional stratigraphic subdivision is based on inhomogenities caused by different materials or...
|
|
|
Sedimentologic and microfacies study of the Suchomasty Limestone at Zlatý kůň Hill near Koněprusy (Lower Devonian - Dalejan)
Polecha, Roman ; Vacek, František (advisor) ; Čáp, Pavel (referee)
This master thesis comprises results of sedimentologic, microfacies and physical stratigraphic research of the Suchomasty Limestone at Zlatý kůň Hill near Koněprusy (Prague Basin, Lower Devonian - Dalejan). Six instructive sections have been selected for detailed study. Physical stratigraphic records (MS and GRS) have been used for correlation of two lithologically different sections (Section I - to the East of the Herget Quarry and Section IV - near the entrance to the Koněprusy Caves). This comparison showed that both sections correspond to the same stratigraphic level, and thus can be included in one sedimentary system. This assumption is also supported by preliminary results of studies on stratigraphic distribution of conodonts. Stratigraphic variations in MS and GRS may also be used for reconstructions of sedimentary environment and its evolution (e.g., changes in sea level). However, all measured parameters show only low oscillations and reflect probably only local conditions. Five microfacies types corresponding to three facies belts have been identified in the studied sections. The lower part of the Suchomasty Lm. is dominated by fine-grained limestones (MF 1 - tentaculite wackestone/packstone) in the NW part of the area (Section IV - near the entrance to the Koněprusy Caves). They deposited in a...
|
|
|
Placodermi of the Prague Basin (Lower Palaeozoic of the Barrandian area)
Kašpar Vaškaninová, Valéria ; Kraft, Petr (advisor) ; Zajíc, Jaroslav (referee)
Placoderms are restricted to the Devonian in the Prague Basin, occuring on localities dated from the Lochkovian to the Givetian. Černá rokle near Kosoř with the Radotin Limestone is the richest placoderm bearing locality. A revision of specimens from collections of the National Museum in Pra- gue confirms occurences of three species of two genera belonging to the pla- coderm order Acanthothoraci: Radotina kosorensis Gross, 1950; Radotina tesselata Gross, 1958 and Kosoraspis peckai Gross, 1959. Genus Holopeta- lichthys was accepted as valid and a diagnosis of H. primus (Barrande, 1872) was amended. Its assignment to higher taxonomic units remains uncertain. Four morphological types of undeterminable specimens classified in the order Arthrodira are defined. Some previously unpublished morphological structures are figured and described: the median dorsal plate of the thoracic armour of R. kosorensis and its relation to the head shield, the cranial cavities and trunk shield plates of R. tesselata, a well preserved neurocranium and scales of K. peckai, the trunk shield and vertebral column of H. primus and large dermal plates of each Arthrodiran morphotype. The placoderm diversity in the Prague Basin was lower compared to ne- ighbouring areas at the beginning of the Devonian (Lochkovian and Pra- gian). Only...
|
|
|
Silurian and Devonian volcanism of the Prague Basin
Tasáryová, Zuzana
The principal goal of the thesis is to constrain nature of magmatic and alteration processes, character of mantle source(s), geotectonic setting and palaeogeographic implications of the Silurian and Devonian volcanism in Prague Basin (Teplá-Barrandian Unit, Bohemian Massif). The thesis is based on extensive geochemical study covering major- and trace-element geochemistry, neodymium isotope geochemistry and mineral chemistry supported by petrographic and field observations. The most important conclusions of the thesis are as follows: 1. The Silurian volcanic rocks of the Prague Basin represent within-plate, transitional alkali to tholeiitic basalts, which erupted in continental rift setting through thick Cadomian crust. The basalts originated by low degrees of partial melting of garnet peridotite mantle source. Older Wenlock basalts are similar to alkaline ocean island basalts (OIB) derived from subcontinental lithospheric mantle (SCLM), enriched most probably by frozen pods of Ordovician magmas. Younger Ludlow basalts resemble tholeiitic enriched mid-oceanic ridge basalts (EMORB) derived from subduction-modified SCLM depleted by Late Cambrian melting. The Wenlock-Ludlow melting is characterized by contemporaneous mixing of melts derived from both enriched and depleted SCLM mantle domains. 2....
|
guest ::
