| Abstract [eng] |
Silurian period was one of the most dynamic time intervals of Earth’s and Life’s evolution. During this time there were several major global biotic perturbations or so called bioevents. Conodonts (primitive vertebrates) were a major part of Silurian ecosystems. Due to the fact that the fossil record of these animals is very abundant and of high quality, its study promises new insights studying macroevolution and macroecology. Using material from seven Lithuanian cores, which span different environments of the Silurian Baltic sedimentary basin, conodont paleoecological dynamics, selectivity of their extinctions, biostratigraphic distribution, and cyclostratigraphy of the basin were studied. During this work three of the most dynamic time intervals of the Silurian were investigated: Ireviken event, Mulde event, and mid- to late Pridoli. Performed statistical analyses of conodont extinction selectivity during the Ireviken event have shown that the most important factors which influenced their survival were environmental preferences and also dynamic structure of their abundance. During this work paleoecological and taxonomic turnover of conodonts was reconstructed for the Mulde bioevent interval. It was shown that conodont abundance dynamics during the Pridoli were characterized by multifractal structure, at least two state shits in correlations between abundances and bio-productivity of seas, and also that abundance was partially driven by astronomic Milankovitch cyclicities. |
