Scientists suggest ancient humans arrived here earlier
Mastodon marks could be Neanderthal’s work
In a provocative claim, scientists say a scattering of bones and stones suggests ancestral humans reached the New World more than 100,000 years earlier than previously thought.
Most genetic and archaeological evidence shows humans first entered the Americas about 15,000 years ago. But a study nearly 25 years in the making in this week’s Nature found that the 130,000- year- old bones of a mastodon, an extinct relative of the mammoth, un- earthed in California were split open with blows from rocks. Rocks near the bones bear the hallmarks of use as hammers, the scientists reported.
The smashed bones may have been the handiwork of a Neanderthal, the scientists say, or the more ancient human relative called Homo erectus, or even our own species, Homo sapiens.
“We are making a claim that’s kind of out there,” acknowledges study co- author Daniel Fisher of the University of Michigan.
Experts not involved in the study question the claim, in part because of the lack of other evidence of a human presence so long ago. “Broken bones and stones alone do not make a credible archaeological site,” says Jon Erlandson of the University of Oregon, who was not involved in the study.
In 1992, a backhoe revealed mastodon remains during construction in San Diego.
The bone fragments, some from a mastodon’s stout thigh, were scarred with marks and notches that are hallmarks of a violent blow on fresh bone. The researchers found three bulky “hammer stones,” possibly used to bash the bones.
The scientists tested their interpretations on skeletons from modern- day elephants. When the scientists slammed rocks into the elephant bones, they recreated the damage seen on the mastodon bones. Aside from ancient humans, none of the predators of 130,000 years ago could break open a mastodon thighbone, researchers say. They ruled out damage by water and by animals stepping on the bones.