Washington, April 3: Archaeologists digging in a dusty cave in Oregon (US) have unearthed fossilized feces dating back to 14,300 years, which appears to be the oldest biological evidence of humans in North America.

According to a report in Seattle Times, if these results hold up, that means the continent was populated more than 1,000 years before the so-called Clovis culture, long believed to be the first Americans.

“This adds to a growing body of evidence that the human presence in the Americas predates Clovis,” said Michael Waters, an anthropologist at Texas A&M University.

DNA analysis of the dried excrement shows that the people who lived in the caves were closely related to modern Native Americans. Their genetic roots reach across the Bering Strait to Siberia and eastern Asia.

“These are probably the ancestors of some of the Native Americans living in America now,” said Eske Willerslev, director of the Centre for Ancient Genetics at the University of Copenhagen.

Of six coprolites from Oregon identified as human by DNA and protein analysis, three dated to around 14,000 years.

The team collected DNA from all 67 people who might have come in contact with the feces, to rule out the possibility of contamination with modern genetic material.

But the scientists also found traces of DNA from foxes, wolves or coyotes in some of the samples.

“The most likely explanation is that the early humans ate the animals, or that animal urine got mixed with the feces,” said Dennis Jenkins, the University of Oregon archaeologist who led the excavations.

The age of the finding also calls into question the theory that people who crossed the Bering Land Bridge to Alaska migrated south through ice-free corridors as glaciers began to break up.

Geological evidence suggests the corridors weren’t open 14,300 years ago, though the glaciers had pulled back from the coasts.

“People probably came either by boat or maybe even walking along the West Coast,” said Willerslev.

Before the Oregon discovery, the oldest human remains in North America were two sets of bones about 13,000 years old from California and Nevada. (ANI)