This work is focused on systematic research of cephalopod jaws from the Late Cretaceous. Samples of 147 newly recorded nautiloid rhyncholites from the Bohemian Cretacoeus Basin and one new ammonite rhyncholite from Řepov village were systematically analyzed. The new collection of lower ammonite jaws (aptychi) consists of 32 specimens. Nautiloid rhyncholites from localities Turkaňk, Úpohlavy, and Dreisen were determined as Nautilorhynchus simplex. Conchorhynchs from locality Vinary u Vysokého Mýta belong to the species Conchorhynchus cretaceous, which is associated with the commonmost species Eutrephoceras sublaevigatum. Ammonite rhyncholite is left in the open nomenclature due to its uncertain systematic position and it is not assigned to any ammonite species. Records of aptychi from the locality of Úpohlavy and Pecínov represent mainly species of heteromorphic ammonites - baculitids (Baculites, Sciponoceras). The total diversity of species from both localities reaches 20 ammonite species. The two jaw morphotypes (2 species of aptychi) are reported from the Bohemian Cretaceous Basin for the first time herein. Of the high importance, it is a record of ammonite Prionocyclus germari from Úpohlavy with associated lower jaws in situ within the body chamber. Aptychus of this taxon has never been...

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this work were analyzed the Spatangoids Echinoids of the species Mecaster batnensis (Coquand, 1862), Mecaster fourneli (Agassiz & Desor, 1847) and Mecaster africanus (Coquand, 1862) from the Sergipe sub-basin of the Fundação Paleontológica Phoenix collection. Among the specimens studied, there were found exemplars of the species Mecaster texanus (Roemer, 1849), that were recorded for the first time in the Sergipe Cretaceous. It was observed that the species M. batnensis and M. africanus, distributed from the Cenomanian to the Turonian showed a lower number of pore pars in the ambulacra III when compared to the others Mecaster species in this same interval. This data could indicate that this species lived in lower depths in the sediment, since the podia of those pores would be sparser. On the other hand, M. fourneli and M. texanus distributed between the Turonian and Coniacian showed a higher number of pore pairs in the ambulacra III, what could indicate that these species lived at more profound depths in the sediment and their contacts with the water-sediment interface through the podia were more effective. All the Mecaster species were present at the basin during the Turonian where they had occupied different habitats, M. batnensis and M. africanus on the other hand would search more profound places where they would live borrowed closer to the water-sediment interface and protected from predators. M. fourneli and M. texanus would prefer shallow environments where they would ride from their predadors burrowed deeply in the sediment. / Neste trabalho foram analisados os equinoides espatangoides Mecaster batnensis (Coquand, 1862), Mecaster fourneli (Agassiz & Desor, 1847) e Mecaster africanus (Coquand, 1862) provenientes da sub-bacia de Sergipe e depositados nas coleções de Invertebrados fósseis da Fundação Paleontológica Phoenix. Entre os espécimes estudados foram encontrados exemplares de Mecaster texanus (Roemer, 1849) sendo esta espécie registrada pela primeira vez para o Cretáceo de Sergipe. Foi observado que as espécies Mecaster batnensis e M. africanus distribuídos do Cenomaniano ao Turoniano apresentaram um número menor de pares de poros no ambulacro III do que as demais espécies neste mesmo intervalo, o que poderia indicar que teriam tido a capacidade de se enterrar a uma menor profundidade no sedimento, já que os pódios destes poros seriam mais espaçados. As espécies Mecaster fourneli e M. texanus foram distribuídas entre o Turoniano e o Coniaciano e apresentaram um maior número de pares de poros no ambulacro III, podendo indicar que estas espécies teriam se enterrado mais profundamente e seu contato com a interface água/sedimento através dos pódios mais efetivo. Todas as espécies de Mecaster estiveram presentes na bacia durante o Turoniano, onde teriam ocupado habitat distinto. Enquanto Mecaster batnensis e M. africanus teriam procurado locais talvez mais profundos onde teriam vivido enterrados mais próximo da interface sedimento/água e afastados de prováveis predadores, M. fourneli e M. texanus teriam preferido ambientes mais rasos onde teriam driblado seus predadores se enterrando mais profundamente no sedimento.

Upper Turonian and Lower Coniacian calcareous nannoplankton stratigraphy in the borehole V 800 Střeleč, Bohemian Cretaceous Basin Number of biostratigraphic studies has been performed within the Upper Cretaceous platform sediments of the NW Europe, however, the problem of Turonian-Coniacan boundary has not yet been satisfactorily resolved using available methods in the field of micropaleontology. The proposed thesis has described the species composition of calcareous nannoplankton assemblages in the Bohemian Cretaceous Basin, across the Upper Turonian- Lower Coniacian interval, focusing on the stratigraphically and paleoecologically important species. Seventy-three taxa of calcareous nannofossils in the studied material have been determined and signifiant species have been discussed (Marthasterites furcatus, Kamptnerius magnificus, Lucianorhabdus sp., Braarudosphaera sp., Nannoconus sp., Watznaueria barnesae, Uniplanarius gothicus, Quadrum gartneri, Thoracosphaera operculata). For purposes of this thesis, a suitable material from the V 800 Střeleč borehole, one of the key cretaceous profil in the Český ráj area, was obtained.

As part of the wider European GTS Next project, I propose new constraints on the ages of the Late Cretaceous, derived from a multitude of geochronological techniques, and successful stratigraphic interpretations from Canada and Japan. In the Western Canada Sedimentary Basin, we propose a new constraint on the age of the K/Pg boundary in the Red Deer River section (Alberta, Canada). We were able to cyclostratigraphically tune sediments in a non-marine, fluvial environment utilising high-resolution proxy records suggesting a 11-12 precession related cyclicity. Assuming the 40Ar/39Ar method is inter-calibrated with the cyclostratigraphy, the apparent age for C29r suggests that the K/Pg boundary falls between eccentricity maxima and minima, yielding an age of the C29r between 65.89 ± 0.08 and 66.30 ± 0.08 Ma. Assuming that the bundle containing the coal horizon represents a precession cycle, the K/Pg boundary is within the analytical uncertainty of the youngest zircon population achieving a revised age for the K/Pg boundary as 65.75 ± 0.06 Ma. The Campanian - Maastrichtian boundary is preserved in the sedimentary succession of the Horseshoe Canyon Formation and has been placed ~8 m below Coal nr. 10. Cyclostratigraphic studies show that the formation of these depositional sequences (alternations) of all scales are influenced directly by sea-level changes due to precession but more dominated by eccentricity cycles proved in the cyclostratigraphic framework and is mainly controlled by sand horizons, which have been related by autocyclicity in a dynamic sedimentary setting. Our work shows that the Campanian - Maastrichtian boundary in the Western Canada Sedimentary Basin coincides with ~2.5 eccentricity cycles above the youngest zircon age population at the bottom of the section and ~4.9 Myr before the Cretaceous - Palaeogene boundary (K/Pg), and thus corresponds to an absolute age of 70.65 ± 0.09 Ma producing an ~1.4 Myr younger age than recent published ages. Finally, using advances with terrestrial carbon isotope and planktonic foraminifera records within central Hokkaido, Northwest Pacific, sections from the Cretaceous Yezo group were correlated to that of European and North American counterparts. Datable ash layers throughout the Kotanbetsu and Shumarinai section were analysed using both 40Ar/39Ar and U-Pb methods. We successfully dated two ash tuff layers falling either side of the Turonian - Coniacian boundary, yielding an age range for the boundary between 89.31 ± 0.11 Ma and 89.57 ± 0.11 Ma or a boundary age of 89.44 ± 0.24 Ma. Combining these U-Pb ages with recent published ages we are able to reduce the age limit once more and propose an age for the Turonian - Coniacian boundary as 89.62 ± 0.04 Ma.

Dans le cadre du projet Européen GTS Next, nous avons obtenu des nouvelles contraintes sur l’âge des étages du Crétacé Supérieur à partir de plusieurs techniques de géochronologie et d’interprétations stratigraphiques au Canada et au Japon. Dans le bassin sédimentaire du Western Interior Canada, nous proposons une nouvelle détermination de l’âge de la limite Crétacé - Tertiaire (K/Pg) enregistrée dans la coupe de Red Deer River (Alberta). Il a été possible de calibrer par cyclostratigraphie haute-résolution cette série sédimentaire fluviatile non-marine et d’identifier 11-12 cycles associés à la précession orbitale de la Terre. En considérant la technique 40Ar/39Ar intercalibrée avec la cyclostratigraphie, l’âge apparent de la base du chron magnétique C29r suggère que la limite K/Pg se trouve entre un minimum et un maximum de l’excentricité, avec une durée pour C29r de 66.30 ± 0.08 à 65.89 ± 0.08 Ma. En supposant que le cycle contenant le niveau de charbon soit associé à un cycle de précession, l’âge révisé de la limite Crétacé - Tertiaire est donné par la plus jeune des populations de zircon datée par U-Pb à 65.75 ± 0.06 Ma.La limite Campanien – Maastrichtien est également enregistrée dans ce même bassin canadien, et se trouve à environ 8 m sous le niveau de charbon No. 10 dans la formation de Horseshoe Canyon. L’étude cyclostratigraphique montre que le dépôt de cette séquence sédimentaire est directement influencé par les changements du niveau marin dû à la précession et dominés par l’excentricité Notre travail montre que la position de la limite Campanien – Maastrichtien dans ce bassin sédimentaire du Western Canada est placée à environ 2.5 cycles d’excentricité au dessus d’un niveau de téphra de la base de la coupe dont l’âge U-Pb est donné par la plus jeune population des zircons, et ~4.9 Myr avant la limite Crétacé - Tertiaire. Nous en déduisons un âge absolu de 70.65 ± 0.09 Ma pour la limite Campanien – Maastrichtien, ce qui est ~1.4 Myr plus jeune que les études récemment publiées.Enfin, à partir des isotopes du carbone et des foraminifères planctoniques enregistrés au centre d’Hokkaido (Pacifique Nord-Ouest), les coupes Crétacé du groupe Yezo ont été corrélée avec les séries européennes et nord-américaines. Plusieurs niveaux de téphra prélevés au sein des coupes de Kotanbetsu et Shumarinai ont été datés par les méthodes 40Ar/39Ar and U-Pb. Deux d’entre eux, placés de part et d’autre de la limite Turonien – Coniacien, ont donné des âges de 89.31 ± 0.11 et 89.57 ± 0.11 Ma, ce qui suggère un âge de 89.44 ± 0.24 Ma pour cette limite. En combinant notre résultat avec les âges récemment publiés, nous pouvons proposer un âge de 89.62 ± 0.04 Ma pour la limite Turonien – Coniacien. / As part of the wider European GTS Next project, I propose new constraints on the ages of the Late Cretaceous, derived from a multitude of geochronological techniques, and successful stratigraphic interpretations from Canada and Japan. In the Western Canada Sedimentary Basin, we propose a new constraint on the age of the K/Pg boundary in the Red Deer River section (Alberta, Canada). We were able to cyclostratigraphically tune sediments in a non-marine, fluvial environment utilising high-resolution proxy records suggesting a 11-12 precession related cyclicity. Assuming the 40Ar/39Ar method is inter-calibrated with the cyclostratigraphy, the apparent age for C29r suggests that the K/Pg boundary falls between eccentricity maxima and minima, yielding an age of the C29r between 65.89 ± 0.08 and 66.30 ± 0.08 Ma. Assuming that the bundle containing the coal horizon represents a precession cycle, the K/Pg boundary is within the analytical uncertainty of the youngest zircon population achieving a revised age for the K/Pg boundary as 65.75 ± 0.06 Ma. The Campanian - Maastrichtian boundary is preserved in the sedimentary succession of the Horseshoe Canyon Formation and has been placed ~8 m below Coal nr. 10. Cyclostratigraphic studies show that the formation of these depositional sequences (alternations) of all scales are influenced directly by sea-level changes due to precession but more dominated by eccentricity cycles proved in the cyclostratigraphic framework and is mainly controlled by sand horizons, which have been related by autocyclicity in a dynamic sedimentary setting. Our work shows that the Campanian - Maastrichtian boundary in the Western Canada Sedimentary Basin coincides with ~2.5 eccentricity cycles above the youngest zircon age population at the bottom of the section and ~4.9 Myr before the Cretaceous - Palaeogene boundary (K/Pg), and thus corresponds to an absolute age of 70.65 ± 0.09 Ma producing an ~1.4 Myr younger age than recent published ages. Finally, using advances with terrestrial carbon isotope and planktonic foraminifera records within central Hokkaido, Northwest Pacific, sections from the Cretaceous Yezo group were correlated to that of European and North American counterparts. Datable ash layers throughout the Kotanbetsu and Shumarinai section were analysed using both 40Ar/39Ar and U-Pb methods. We successfully dated two ash tuff layers falling either side of the Turonian - Coniacian boundary, yielding an age range for the boundary between 89.31 ± 0.11 Ma and 89.57 ± 0.11 Ma or a boundary age of 89.44 ± 0.24 Ma. Combining these U-Pb ages with recent published ages we are able to reduce the age limit once more and propose an age for the Turonian - Coniacian boundary as 89.62 ± 0.04 Ma.