Deep in the water of a Yucatán Peninsula cave, one of the oldest human skeletons found in North America has been discovered. 

"Naia" is the the researchers' name for the teenage girl who went underground, presumably to seek water, and fell to her death in a large pit named Hoyo Negro - "black hole" in Spanish.

The girl's skeleton is between 13,000 and 12,000 years old and genetic analysis shows the prehistoric girl and living Native Americans came from the same place during the initial peopling of the Americas. The near-complete human skeleton -- with an intact cranium and preserved DNA -- was discovered lying 130 feet below sea level near a variety of extinct animals, including an elephant-like creature called a gomphothere. These remains helped scientists establish the age of the skeleton. 

Divers transport the skull, part of the oldest complete skeleton yet discovered in the Americas, for 3-D scanning. Photograph By Paul Nicklen, National Geographic

Led by Pilar Luna of the Mexican government's National Institute of Anthropology and History (INAH) and James Chatters of Applied Paleoscience, 15 experts from a wide range of fields have been focused on telling the story of the young woman and Hoyo Negro since the skeleton's discovery in 2011. 

"The preservation of all the bones in this deep water-filled cave is amazing -- the bones are beautifully laid out," said cave-diving scientist Patricia A. Beddows of Northwestern University, who has hovered underwater above the skeleton's site and prospected in the area. "The girl's skeleton is exceptionally complete because of the environment in which she died -- she ended up in the right water and in a quiet place without any soil. Her pristine preservation enabled our team to extract enough DNA to determine her shared genetic code with modern Native Americans."  

"Research in flooded caves is much like space exploration, with divers similar to astronauts reporting back to 'mission control' -- a much larger scientific team at the surface," Beddows said. "It all has to be done on SCUBA, which is our life support system. Our science team has been supported by a great number of dedicated non-science cave divers who have committed hundreds of hours at very dangerous depths to complete this exploration."

Part of her remains have been removed from Hoyo Negro for safekeeping, after unauthorized divers entered the chamber to take photographs, moving and damaging some bones in the process. "We tried to keep everything in situ," Mariá del Pilar Luna Erreguerena, head of underwater archaeology for Mexico's National Institute of Anthropology and History, told National Geographic. But leaving Naia's remains in place was deemed too big a risk. Her watery grave is an attractive target, one Chatters likens to "a mini La Brea Tar Pits, only without the tar and considerably better preservation."