CONICET | Buscador de Institutos y Recursos Humanos

This chapter aims to synthesize the current state of knwledge on the Proterozoic and Lower Paleozoic fossils of Argentina. A wide range of taxonomic groups are considered, specially those from marine environments. First, the paleontological and evolutionary significance of Vendian-Lower Cambrian ichnofaunas is analyzed in order to understand early colonization of marine substrate and the roile played by the microbial communities in the ecologic sstructure. Paleoecology of Ordovician faunas has been the focus of numerous studies, boths at communitie and biofacies scale. Comparative studies among different Ordovician basins allowed to recognize different type-assemblages defined on the basis of the overall taxonomic diversity, alpha diversity and ecospace utilization. The evolutionary faunas model has been critically analyzed from the evidence of gondwanan assemblages, suggesting that it is not entirely applicable at a global scale. A considerable progress has been made in the stratigraphic analysis of the rich Lower Paleozoic conodont, graptolite, trilobite and palinomorph assemblages from the Upper Cambrian, Ordovician and Silurian of Argentina, leading to stablish accurate biostratigraphic schemas.