When did the first Americans arrive on Turtle Island?

Clovis claim in jeopardy...

WASHINGTON - The Clovis people, known for their distinctive spear points, likely were not the first humans in the Americas, according to research placing their presence as more recent than previously believed.
Using advanced radiocarbon dating techniques, researchers writing in Friday's issue of the journal Science said the Clovis people, hunters of large Ice Age animals such as mammoths and mastodons, dated from about 13,100 to 12,900 years ago.
That would make the Clovis culture, known from artifacts discovered at various sites including the town of Clovis, N.M., both younger and shorter-lived than previously thought. Previous estimates had dated the culture to about 13,600 years ago.

For the source and the rest of the story go to
http://www.msnbc.msn.com/id/17298212/?GT1=9033