During the last 540 million years, the history of life on Earth has been punctuated by severe mass extinctions, brief periods when biodiversity collapsed. At the boundary between the Paleozoic and Mesozoic eras (approximately 252 million years ago), the end-Permian mass extinction was the most devastating global-scale event ever recorded, resulting in the loss of more than 90% of marine species. During long and intense debate about the potential causes of this major crisis, considerable effort has been devoted to investigating the unusual ecological patterns that arose during its aftermath. Until recently, several studies suggested that the biosphere took between 5 and 30 million years to reach the levels of biodiversity seen before the extinction. However, recent findings on pelagic organisms such as ammonoids and conodonts indicate a rapid and explosive recovery in less than 2 million years. This duration contrasts radically with patterns observed for benthic biota (living on or within the sea floor), which are based mainly on fragmentary data. It also suggests that recovery rates for numerous taxa need to be reevaluated and that ecosystem reorganization may occur rapidly after a mass extinction.