A new study has created a stir among archaeologists. The research claims that ancient humans arrived in the Americas far earlier than previously assumed.
The researchers shared that signs of human activity have been found in California between 120,000 and 140,000 years ago. Based on this assertion, the difference between the new claims and the old assumptions of human settlement in the Americas is more than a 100,000 years.
The researchers of the new study arrived at this conclusion after dating the archaeological remains at the Cerutti Mastodon site, which has pushed back the arrival of ancient humans to 130,000 years rather than just 15,000 years.
"I realize that 130,000 years is a really old date and makes our site the oldest archaeological site in the Americas," Tom Deméré, the study's lead author, told The National Geographic.
Cerutti Mastodon Site: What Was Discovered?
Human remains have not been found at the site of the new study. However, bones and teeth of ancient animals similar to elephants have been discovered at the site. The animal fossil remains bore signs of modification by human hands, stone hammers, and anvils. Based on the circumstantial evidence, the researchers concluded the presence of humans in California 130,000 years ago.
Deméré and his team assume that Cerutti Mastodon was used as a "bone quarry" given the presence of bone flakes, a mastodon skeleton, and several large stones. In ancient times, humans supposedly smashed mastodon bones with the help of stone hammers and anvils to extract bone marrow and raw materials from the skeleton.
Although the site of the new study was discovered in 1992, revelations regarding the same came to the fore in 2011 and 2012 due to difficulty in accurately dating the site.
What Does The Site Evidence Indicate?
Based on the evidence analyzed from Cerutti Mastodon, Deméré and his colleagues arrived at the conclusion that ancient humans arrived 130,000 years ago in California.
Richard Fullagar, an archaeologist at University of Wollongong in Australia and also a team member of the controversial study, shared that the rocks bear signs of wear and tear. These appear to be inflicted from ancient stone tools, especially those used for shattering bones.
The researchers assert that the stone placement also indicated human presence. The Cerutti Mastodon site was entombed with siltstone. However, bigger rocks displaying the signs of wear are far heavier than the surrounding sedimentary siltstones. This indicated that humans brought the rocks.
The archaeologists also revealed that the fractures found on the mastodon bones indicated that they were broken while the bones were still fresh. They also asserted that the bone smashing was a sure result of human activity and not an occurrence of nature.
"Discovered in 1992 during construction work to expand an expressway, the bone fragments "show clear signs of having been deliberately broken by humans with manual dexterity," lead author Steve Holen asserted.
Humans In California 130,000 Years Ago: Other Archaeologists Skeptical?
Several archaeologists are skeptical of the findings, some even dismissed them outright. One of the main criticisms of the study is that it does not conclusively rule out natural causes for the breakage of mastodon bones, presence of stone tools, and breakage patterns on the rock surfaces.
Many archaeologists such as Tom Dillehay, from Vanderbilt University shared that the research fails to entirely exclude the possibility of natural processes involved in the movement of the rocks, or creating the wear pattern on the stones. He also noted that these could have taken place easily if the rocks bumped against each other in a stream.
However, Holen and Deméré are prepared to answer questions, which they are aware could come up once the controversial study is publicized.
"I think we've made a very good case that this is an archaeological site. I think we're quite prepared for the firestorm that's coming," Holen told The National Geographic.
The paper has been published in the journal Nature on Wednesday, April 26