Fascinating new study that combines the most current research on mass extinctions with the theoretical perspectives of the leaders in the field. In 20 engaging essays more than 30 thirty leading palaeobiologists and palaeontologists uncover a wealth of data from the fosil record about changes in species survival and physical environments across the Cretaceaous-Tertiary (K-T) boundary. Together these papers present a much-awaited global perspective on the biological and environmental changes taking place during this critical period in the history of life.