This thematic volume arose from a desire to acknowledge the pioneering
contributions to mass extinction studies made by Professor Tony Hallam over the
past 50 years and includes papers from several theme sessions held at the annual
meeting of the Geological Society of America held in Denver in October 2013
along with other solicited contributions. They provide both a breadth of
temporal coverage and also reflect the broad spectrum of earth scientists
currently involved in studying these ancient crises, ranging from
palaeontologists to volcanologists to earth system modellers.