http://news.yahoo.com/s/afp/20050705/sc_afp/britainmexico_050705191119
LONDON (AFP) - British scientists said they have found 40,000-year-old human footprints in central Mexico, shattering theories that mankind arrived in the Americas tens of thousands of years later from Asia.
The discovery was made in September 2003 near the city of Puebla, 130 kilometers (88 miles) southeast of Mexico City, said Silvia Gonzalez, from Liverpool John Moores University (LJMU), who led the team of researchers.
The footprints, which were found in an abandoned quarry close to the Cerro Toluquilla volcano, were subsequently studied and dated by a multinational team of scientists.
“The footprints were preserved as trace fossils in volcanic ash along what was the shoreline of an ancient volcanic lake,” Gonzalez said. “Climate variations and the eruption of the Cerro Toluquilla volcano caused lake levels to rise and fall, exposing the volcanic ash layer.”
She said the discovery challenges the traditionally held view that settlers first crossed the Bering Straits, from Russia to Alaska, at the end of the last ice age, around 11,500 to 11,000 years ago.
Evidence for this theory comes from “Clovis Points” tools used to hunt mammoths found in many locations in the American continent.
But the discovery of footprints provides new evidence that humans settled in the Americas as early as 40,000 years ago, Gonzalez said.
“We think there were several migration waves into the Americas at different times by different human groups,” she said.
Working with Gonzalez were LJMU colleague David Huddart and Matthew Bennett of Bournemouth University.
She said the early Americans would have been curious about the volcano erupting and walked across this new shoreline, leaving behind footprints that soon became covered in more ash and lake sediments.
The trails became submerged when the water levels rose again, so preserving the footprints.
Now as hard as concrete, the ash is used locally as a building material.
The team was able to see the footprints without carrying out any excavation as quarry workers had already removed between lake sediments that had been deposited on top of the volcanic ash.
. The word “descended” seems somehow particularly apt…
