WASHINGTON, Jan. 15 (Xinhua) -- The frozen carcass of a prehistoric mammoth with signs of weapon-inflicted injuries suggested that humans were present in the Arctic 10,000 years earlier than previously thought, a Russian study has found.
The results, published in the Friday issue of the U.S. journal Science, provided perhaps the earliest known evidence of human survival in the Arctic region, dating human presence there to roughly 45,000 years ago, instead of 35,000 years ago, as previously thought.
The remains of the male woolly mammoth were excavated in 2012 by Alexei Tikhonov and his colleagues with the Russian Academy of Sciences from frozen sediments in a coastal bluff on the eastern shore of Yenisei Bay, in the central Siberian Arctic.
Through radiocarbon dating of the animal's tibia bone and surrounding materials, the researchers dated it at 45,000 years old.
The mammoth's bones exhibited a number of unusual injuries on the cheekbone, ribs and mandible, including dents likely from sharp weapon tips such as thrusting spears, the researchers said.
Damage to the only preserved tusk, the right tusk, of the mammoth reflected an attempt by humans to separate the outside of the tusk by chopping, they said.
Thus, the mammoth bone remains provided well-supported evidence for human involvement in its death, indicating people were present in the central Siberian Arctic by about 45,000 years ago, they concluded.
"Apparently, humans' ability to survive in the Arctic environment, and their spread within the region as early as 45 ka (thousand years ago), represents an important cultural and adaptational shift," they wrote in the paper. "We speculate that adaptation changes that ensured human survival there may be related to innovations in mammoth hunting. Sustained development of the populations, secured by an abundant food source, could have led to their rapid spread across the Siberian Arctic."
In the end, the early arrival of humans in the area close to the Bering land bridge that once linked Siberia and North America may have provided them an opportunity to enter the New World about 20,000 years ago, the researchers added.