About 252 million years ago the largest extinction in history happened at the end of the Permian period. About 90% of marine life disappeared in a relatively short period and so far paleontologists believed that it took around 8-9 million years before, in the Triassic period, large predators reappeared. Now a study of a group of paleontologists led by Torsten Scheyer and Carlo Romano of the University of Zurich, Switzerland, claims that new predators quickly emerged at the beginning of the Triassic.