Seaweed found at an inland settlement in Chile confirms that the village is one of the oldest inhabited sites in the Americas and demonstrates that residents had extensive contact with the coastline, 50 miles away, researchers said Friday.
Radiocarbon dating of the seaweed shows that the samples are 14,100 years old, give or take 120 years. That means the site, called Monte Verde, is at least a millennium older than the so-called Clovis sites in the American Southwest, long believed to be the most ancient in the New World.
The report comes just a month after researchers reported similar dates for fossilized human feces, called coprolites, found in Paisley Cave in Oregon.
Together, the reports support the growing idea that the first immigrants to the Americas arrived from Asia over a land bridge across what is now the Bering Strait and made their way down the Pacific Coast as far as South America, exploiting abundant marine resources as they traveled.
Monte Verde -- now in a peat bog, about 500 miles south of Santiago and 10 miles from the coast -- contained about a dozen huts on a minor creek, 10 miles north of a large bay. Perhaps 20 to 30 people lived there, said archaeologist Tom D. Dillehay of Vanderbilt University in Tennessee, who has been studying the site for 30 years.
Seaweed was found throughout the site, Dillehay and his colleagues reported in the journal Science. Some samples were commingled with plants in cuds obviously chewed by residents for their medicinal value. Others, scattered around the huts, were probably food. The plants are good sources of iodine, iron, zinc and other nutrients.
Dillehay had previously identified four species of seaweed in the cuds. In the new study, they identified five more originating on the coast, and several from the nearby bay.
Other coastal materials at the site included flat beach pebbles and water plants from brackish estuaries.
"Finding seaweed wasn't a surprise, but finding five new species in the abundance that we found them was a surprise," Dillehay said. "The Monte Verdeans were really like beachcombers. The number and frequency of these items suggests very frequent contact with the coast, as if they had a tradition of exploiting coastal resources."
The team also found inland materials, including vegetables, nuts, an extinct species of llama and an elephant-like animal called a gompothere. The fact that both coastal and inland items were found indicates that the Monte Verdeans were spending enough time at each location to learn about geography and resources.
That suggests, Dillehay concluded, that "the peopling of the Americas may not have been the blitzkrieg movement to the south that people have presumed, but a much slower and more deliberate process."