Oregon stone tools enliven 'earliest Americans' debate

Scientists studying how North America was first settled have found stone spearheads and darts in Oregon, US, that date back more than 13,000 years.

The hunting implements, which are of the "Western Stemmed" tradition, are at least as old as the famous Clovis tools thought for a long time to belong to the continent's earliest inhabitants.

Precise carbon dating of dried human faeces discovered alongside the stone specimens tied down their antiquity.

It has published the scholarly findings of an international team investigating the Paisley Cave complex in south-central Oregon....