Geological and palaeoenvironmental history of the Scotia Sea region as a basis for biological interpretation

There is an extensive literature on the geological development of the Scotia Sea and the Scotia arc, and its relations to the development of the Antarctic Circum-polar Current (ACC) and potential implications for Antarctic glaciation. However, most of the relevant papers have been written from a tectonic or geophysical perspective, with no consideration of the biological implications of the momentous changes involved. This review is an attempt to summarise aspects of the geographical, oceanographical and climate changes that are likely to have had biological consequences for the marine faunas of the Magellan–Antarctic region. There remain many uncertainties over the timing of events and the paucity of information on the palaeogeographical history of the fragments of the Scotia arc. Thus, whilst there is a growing body of evidence to suggest that the first Antarctic ice sheets, the opening of Drake Passage and the development of the ACC occurred within just a few million years of each other, there is not yet enough precision to be sure of the possible interrelationships, if any. Furthermore, an exposed rock record that is very limited in both stratigraphical and geographical extent leaves many uncertainties concerning the distribution of fossil animals in space and time. Despite the difficulties and uncertainties, however, much can be done with the existing data by taking a truly multidisciplinary approach, firstly to reassess possible interrelationships between physical and biological knowledge of the area, and secondly to direct future research in the region.