NEW YORK – Stone tools salvaged during a dig in China suggest that our evolutionary ancestors walked earlier than we thought.

Until now, the earliest evidence of human creatures outside of Africa came from 1.8 million years ago. artifacts and skulls found in the Georgian city of Dmanisi. But the new discovery is pushing it back at least 250,000 years.

"It's absolutely a new story," said archaeologist Michael Petraglia of the Max Planck Institute for the Science of Human History in Jena, Germany, which does not Did not participate in the study. "This means that the first humans were coming out of Africa sooner than we had ever realized."

This exit came well before our own species, Homo sapiens, appeared. The researchers believe the tools were made by another member of the evolutionary Homo group.

Items included several chipped rocks, fragments and hammer stones. The 96 artifacts were unearthed in an area known as the Loess Plateau, north of the Qinling Mountains, which divide north and south China.

Some of them were as old as 2.1 million years old. Nature Journal

"We were very excited," said Zhaoyu Zhu, a professor at the Guangzhou Institute of Geochemistry, who led the field work. "One of my colleagues suddenly noticed a stone embedded in a steep spur and after a short while, more artifacts were found – one after the other."

The tools were distributed through the layers of land. the same site again and again, maybe follow animals to hunt. The researchers also found bones of pigs and deer, but were not able to provide evidence that the tools were used for hunting.

Some experts who do not participate in research believe that the results should be taken with caution. I am skeptical, "said Geoffrey Pope, an anthropologist at the William Paterson University of New Jersey. "I suspect that this discovery will change very little."

The problem, he said, is that sometimes nature can model stones in a way that they seem to have been handcrafted. Scientists know, for example, that rocks broken together in a stream can acquire sharp edges.

But Sonia Harmand, archaeologist at Stony Brook University in New York, does not agree

. The most important (archaeological) sites in the world, "said Harmand, who studies stone tools