The existence of rapid and even catastrophic turnovers within the Phanerozoic ecosystems has been the subject of discussion for more than 170 years, becoming even more intensive after the hypothesis of Alvarez which explained the end-Cretaceous mass extinction as the result of a huge asteroid impact on Earth. This volume presents a thorough discussion of the causes of the various global events, and is part of the international research programme on Global Biological Events in Earth History.