Modern humans' distant relatives left Africa earlier than previously thought—rewriting a key chapter in humankind's epic prequel, according to a discovery unveiled on Wednesday in Nature.

Nearly a hundred stone tools found at the Shangchen site in central China may push back the spread of our ancient cousins—hominins—out of Africa by more than a quarter million years.

The toolmakers lived at Shangchen on and off for 800,000 years between 2.1 and 1.3 million years ago, leaving behind tools that are unprecedented outside of Africa. The site's oldest tools are roughly 300,000 years older than Dmanisi, a 1.8-million-year-old site in the Republic of Georgia with the oldest known fossils of our extinct cousin Homo erectus.

“Finding artifacts that you knew were around