Oversized one-million-year-old gastropod fossils have been discovered by French scientists who think the specimens cast doubt on the existence of the “Lilliput effect”, which is the reduction in the size of organisms inhabiting postcrisis biota, normally spanning several million years. “The team's results, published in the February 2010 issue of the journal Geology, have drastically changed paleontologists' current thinking regarding evolutionary dynamics and the way the biosphere functions in the aftermath of a mass extinction event. The history of life on Earth has been punctuated by numerous mass extinctions, brief periods during which biodiversity is considerably reduced, followed by phases of re-conquest of the biosphere, corresponding to the diversification of those species that survived. Over the last 540 million years, around twenty mass extinctions, of greater or lesser intensity, have succeeded one another. The most devastating of these, the Permian-Triassic (P-T) mass extinction, which decimated more than 90% of the marine species existing at the time, occurred 252.6 million years ago with a violence that is still unequalled today. In the aftermath of such events, environmental conditions are severely disrupted.”