For decades, the accepted theory of human migration suggested that Homo sapiens arrived to America around 15,000 years ago, and that they were the very first humans to roam North America. But this week, in a seriously history-changing discovery, researchers revealed that they uncovered evidence of humans living and hunting in what is now southern California a whopping 130,000 years ago. It’s one of the most significant finds in the archeological record, and it rewrites the book on human presence in America.

The report, which was published in Nature, focuses on the dating of Mastodon remains that were initially discovered in the early 90s. The bones were found during a highway expansion project, and show evidence of having been broken down and processed by human tools. For decades, scientists didn’t know exactly how old they were, but this new data puts its age at around 130,000 years.

But before you go thinking that your our ancient ancestors were hanging out on California beaches way back then, you should know that the humans who were apparently here at that time weren’t Homo sapiens at all. Researchers still have no reason to suspect that Homo sapiens even left Africa until 100,000 years ago at the earliest, which means that whoever was swinging axes at Mastodon bones on the West Coast was likely from a different evolutionary fork of humanity, possibly Neanderthals. Whoever they were, they were here a whole lot earlier than archeologists have ever known, and history books might be due for a rewrite.