A mass extinction of life on Earth may have occurred 10 million years before the largest known extinction took place around 250 million years ago, a Japanese scientist said Monday.
Yukio Isozaki, professor of life extinction history at the University of Tokyo, said he made the discovery along with Ayano Ota, a graduate student. They studied the fossils of fusulinidae, a unicellular organism, in a 40-meter-thick layer of limestone in Takachiho, Miyazaki Prefecture.
A study in southern China, which was a shallow sea some 250 million years ago, has led scientists to believe that mass extinction on Earth occurred in two stages. Isozaki said his findings help verify this two-stage hypothesis.