Early hominids left Africa earlier than thought.

Stone tools unearthed in China help make a case that early hominid ancestors of humans migrated from Africa more than 2 million years ago.

That’s much earlier than any previous evidence showed. According to the findings published in the journal Nature, the tools were found at Shangchen, a newly discovered Paleolithic site of the southern Chinese Loess Plateau.

Researchers led by Zhaoyu Zhu from the Chinese Academy of Sciences in Guangzhou found 82 flaked stone tools and 14 unflaked stones.

“It suggests a way earlier migration out of Africa than we ever would have imagined,” Michael Petraglia, a paleoanthropologist at the Max Planck Institute for the Science of Human History, who was not involved with the study, told LiveScience. “It’s very exciting.”

Before now, the earliest evidence of hominids outside Africa was from a site in the nation of Georgia.

But it’s not far-fetched to think humans could have lived far from Africa 2 million years ago, or even further back than that. According to Gizmodo:

Katerina Harvati, head of paleoanthropology at the Senckenberg Center for Human Evolution and Paleoenvironment, likes the new study, saying the authors did a good job with their fieldwork, dating, and analysis. She said the artifacts are convincing and the use of paleomagnetic dating was appropriate. But Harvati believes there’s room for improvement, both for the geological study of the site, and in the use of other dating techniques.

“I think the work should be expanded with additional fieldwork, especially further excavations at the discovered sites,” Harvati told Gizmodo. “However, the authors have demonstrated human presence at more than two million years ago in East Asia. If the dating is correct, this would be the earliest human presence out of Africa.”

Harvati says it’s surprising that hominins didn’t expand their geographic range out of Africa earlier, especially after the first appearance of stone tools some three million years ago.