We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

When Did the Earliest Humans Reach North America?

Paleontologists examining mastodon bones found in the San Diego area in 1992 have recently proposed that what we know about early humans in North America may be all wrong. In a study published this year in the journal Nature, the research team claims that they see evidence of early man in North America dating back to around 130,000 years ago. Previous research had pegged the arrival of early man on the continent to around 24,000 years ago, so the much-earlier date is controversial, to say the least. The new research is based on the fact that the mastodon bones -- including two tusks, three molars, 16 ribs, and more than 300 bone fragments -- show impact marks, suggesting that they were struck with hard objects. In fact, the researchers also found five “hulking stones,” which they say could have been used as hammers and anvils.

The mystery of the mastodon bones:

  • Two distinct clusters of broken mastodon bones surrounded the stones, suggesting to the researchers that the bones were smashed in that location.
  • Some of the shattered bones contained spiral fractures, indicating that they were broken while still “fresh,” the authors wrote.
  • Attempts at radiocarbon dating were unsuccessful because the bones did not have enough carbon-containing collagen. Instead, the researchers used uranium-thorium dating -- a technique often used to check the dates derived from radiocarbon dating.
Discussion Comments
WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.

WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.