Norwegian fossils may be evidence of major extinction event

Science : There are currently five widely accepted major extinction events . New evidence collected by David Bond of the University of Hull in the UK and his colleagues suggests a sixth event may be added to that list. Occurring 260 million years ago, the extinction marks the end of the Capitanian age . Initial evidence for the extinction event was found in China in the early 1990s. Fossils of foraminifera and brachiopods were found in rocks formed in an ancient tropical sea. But, according to the rock record, they suddenly disappeared. A similar extinction of brachiopods has now been found by Bond’s team in rocks on an island in Norway. The researchers connected the two events by comparing isotope levels, which showed similar variations. The finding suggests that global-scale changes occurred in ocean chemistry. However, because the dating of the event in Norway has not yet been verified, that extinction could have been a separate, regional event.