Based on direct radiocarbon dating of tooth enamel and indirect uranium-thorium dating of flowerlike crystalline deposits on Naia's bones, the researchers suggest her remains are 12,000 to 13,000 years old.
This hinted that she could help reveal a long-standing controversy regarding the mysterious relationship between the earliest Americans and modern Native Americans.
"The people themselves were few; they were highly nomadic and seem to have buried or cremated the dead where they fell, making the locations of graves unpredictable; also, geologic processes have destroyed or deeply buried their graves." Until now, the skeletal remains of the earliest Americans that scientists discovered were typically only fragments.
In addition, most were estimated to be younger than 10,000 years old — the earliest Americans reached the Americas long before that.
"We had no idea what we might find when we initially entered the cave, which is the allure of cave diving," said study author Alberto Nava of Bay Area Underwater Explorers in Berkeley, California.
"The moment we entered the site, we knew it was an incredible place.
"Paleoamerican skeletons are rare for several reasons," Chatters said.The ancient skeleton of a teenage girl found in an underwater cave in Mexico may be the missing link that solves the long-standing mystery behind the identity of the first Americans, researchers say.These findings, the first time researchers have been able to connect an early American skeleton with modern Native American DNA, suggest the earliest Americans are indeed close relatives of modern Native Americans, scientists added."The floor of that cave is a mess, littered with boulders, some of which are room-sized, and the skull could have dropped another 5 meters (16 feet) into a gap where there would have been no room for a diver," Chatters said."The area is now fenced off." Moreover, "the divers had never picked up Naia's skull before, so we didn't know how strong it was," Chatters recalled.