Serra da Capivara National Park Piauí Brazil

Pedra Furada is the most controversial of the excavated prehistoric settlements in the Americas, indicating a human presence there as early as 50,000 BCE.

Pedra Furada ("drilled rock") is an important collection of over eight hundred archaeological sites and rock paintings in Brazil that suggest a human presence prior to the arrival of Clovis people in North America.

The discoveries are the subject of debate as they apparently contradict the "Clovis first" view for humans in the Americas, or short chronology theory, with the first movement beyond Alaska into the New World occurring no earlier than fifteen thousand to seventen thousand years ago, followed by successive waves of immigrants.

Pedra Furada provides arguments for the proponents of the long chronology theory, which states that the first group of people entered the hemisphere at a much earlier date, possibly twenty one thousand to forty thousand ears ago, with a much later mass secondary wave of immigrants.

Genetic studies of indigenous peoples have concluded that the "colonizing founders" of the Americas emerged from a single-source ancestral population that evolved in isolation, likely in Beringia.

The isolation in Beringia might have lasted ten thousand to twenty thousand years.

Age estimates based on Y-chromosome micro-satellite place diversity of the American Haplogroup Q1a3a (Y-DNA) at around ten thousand to fifteen thousand years ago.

This does not address if there were any previous failed colonization attempts by other genetic groups, which could be represented by those settling the Pedra Furada site, as genetic testing can only address current population ancestral heritage.