16,000 YEAR OLD TOOLS DISCOVERED IN TEXAS -- AMONG OLDEST FOUND IN THE WEST

Archaeologists in Texas thought they’d made an important discovery in the 1990s, when they unearthed a trove of stone tools dating back 13,000 years, revealing traces of the oldest widespread culture on the continent.

But then, years later, they made an even more powerful find in the same place — another layer of artifacts that were older still.

About a half-hour north of Austin and a meter deep in water-logged silty clay, researchers have uncovered evidence of human occupation dating back as much as 16,700 years, including fragments of human teeth and more than 90 stone tools.