Sökning: "Late Cretaceous"
Visar resultat 11 - 15 av 19 avhandlingar innehållade orden Late Cretaceous.
11. Dating Divergence Times in Phylogenies
Sammanfattning : This thesis concerns different aspects of dating divergence times in phylogenetic trees, using molecular data and multiple fossil age constraints.Datings of phylogenetically basal eudicots, monocots and modern birds (Neoaves) are presented. Large phylograms and multiple fossil constraints were used in all these studies. LÄS MER
12. Who ate whom? Paleoecology revealed through synchrotron microtomography of coprolites (fossil feces)
Sammanfattning : Fossil droppings, known as coprolites, are being increasingly recognized as a valuable source of paleoecological information with special regard to diets, parasitism, and physiology of extinct taxa. Here, it is suggested that the excellent preservation and amount of inclusions in the coprolites (e.g. LÄS MER
13. Geological development of the East African coastal basin of Tanzania
Sammanfattning : The East African coastal basin of Tanzania, which is characterised by an extensional tectonic style, is located along the passive continental margin of the western Indian Ocean. The present study is concerned with the Mafia Island and the Mafia Channel which together form a subbasin within the north-south elongated coastal sedimentary basin of Tanzania. LÄS MER
14. The flux of extraterrestrial spinels to Earth associated with He-3 anomalies in Cenozoic and Ordovician sediments
Sammanfattning : The main goal of this thesis is to reconstruct the flux of extraterrestrial matter to Earth in specific time intervals of our past in order to add an astronomical dimension to the understanding of Earth's history. To accomplish this, extraterrestrial chrome-spinel grains have been extracted and analysed. LÄS MER
15. 100 million years of shark macroevolution : A morphometric dive into tooth shape diversity
Sammanfattning : Few vertebrate clades exhibit the evolutionary longevity and versatility of sharks, which constitute nearly half of all current chondrichthyan biodiversity and represent an ecological diversity of mid-to-apex trophic-level predators in both marine and freshwater environments. The rich fossil record of shark teeth from Mesozoic and Cenozoic rocks also makes the group amenable to large-scale quantitative analyses. LÄS MER