This group specialises in analysing the Palaeozoic biota recorded in different marine and transitional environments, integrating the diverse palaeontological data in the construction of a biostratigraphic scale of the highest possible precision, allowing global correlations to be integrated and contributing to the elaboration of the International Stratigraphic Chart. These data are also used in the recognition of Events (Geo and Bio, local and global), and in palaeoecological, palaeoclimatic and palaeogeographical reconstructions.