Footprints left behind by prehistoric people may be some of the strongest evidence yet that humans arrived in the Americas earlier than previously thought.
Over 60 “ghost tracks” — so-called because they pop up and disappear across the landscape — show that people romped through what’s now New Mexico 23,000 to 21,000 years ago, geoscientist Matthew Bennett and colleagues report in the Sept. 24 Science. If true, the fossil findings would be definitive proof that humans were in North America during the height of the last ice age, which peaked around 21,500 years ago.
When people first arrived in the Americas is highly contested. Scientists have historically thought that humans traveled across the Bering land bridge that connected Asia to North America around 13,000 years ago, after the massive Laurentide Ice Sheet that once blanketed much of North America had started retreating into the Arctic (SN: 6/26/18). But a slew of more recent discoveries from across North and South America — including roughly 30,000-year-old animal bones from a Mexican cave (SN: 6/9/21) and stone tools from Texas (SN: 7/11/18) — suggest that humans may have arrived far earlier.
At White Sands National Park in New Mexico, Bennett, of Bournemouth University in Poole, England, and colleagues used several methods to calculate the ages of the newly described tracks, including radiocarbon dating of aquatic plants embedded in and between the footprints.
To provide the best experiences, we use technologies like cookies to store and/or access device information. Consenting to these technologies will allow us to process data such as browsing behavior or unique IDs on this site. Not consenting or withdrawing consent, may adversely affect certain features and functions.
Functional
Always active
The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network.
Preferences
The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user.
Statistics
The technical storage or access that is used exclusively for statistical purposes.The technical storage or access that is used exclusively for anonymous statistical purposes. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you.
Marketing
The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes.