The woolly mammoth ("M. primigenius") was the last species of the genus. Most populations of the woolly mammoth in North America and Eurasia, as well as all the Columbian mammoths ("M. columbi") in North America, died out around the time of the last glacial retreat, as part of a mass extinction of megafauna in northern Eurasia and the Americas. Until recently, the last woolly mammoths were generally assumed to have vanished from Europe and southern Siberia about 12,000 years ago, but new findings show some were still present there about 10,000 years ago. Slightly later, the woolly mammoths also disappeared from continental northern Siberia. A small population survived on St. Paul Island, Alaska, up until 3750 BC, and the small mammoths of Wrangel Island survived until 1650 BC. Recent research of sediments in Alaska indicates mammoths survived on the American mainland until 10,000 years ago.