Paul B WignallPaul B. Wignall is Professor of Palaeoenvironments at the University of Leeds, and a leading expert on extinctions. He has published over 200 papers on a multitude of research areas, including the causes of major environmental change such as the deoxgenation of the oceans, and the establishment of super greenhouse climates. In addition to his considerable research output, he has authored a popular science book, The Worst of Times, and has contributed articles to popular science magazines. He has also appeared in many television documentaries, including the recent Walking through Time. Read More Read Less