9,000 years old human remains along with and other mammals bones from the latest Ice Age have been found inside of an underwater cave system in Mexico, the largest urderwater system in the world.
A group of archeologists, speleologists and divers have been researching the Sac Actun (Yucatec Mayan for “White Cave”) for years and they recently connected it with the Dos Ojos system, making it the largest known underwater cave system in the world with 347 kilometers.
“I think it’s overwhelming. Without a doubt it’s the most important underwater archaeological site in the world,” said Guillermo de Anda, a researcher at Mexico’s National Anthropology and History Institute (INAH).
The system has 248 visible “openings”, called cenotes, that give access to it and is located within the Tulum municipality in Quintana Roo, also an archeological site on its surface and a tourist resort. The cenotes are of spiritual importance for the Mayan people who still inhabit the peninsula.
About 198 sites of archeological interest have been found inside the cave system, 138 of them related to the Mayan civilization.
Ceramic ceremonial articles have also been found, and researchers think the cave system could've been a peregrination site.
The human remains have to be further investigated to determine a more exact date of origin, but experts say they are at least 9,000 years old.
Bones of megafauna such as giant sloths, elephants and extinct bears from the Pleistocene period were also found.
“I ask myself in where else can one find archeological sites of such a wide time-span, which range from 15,000 years ago until the castes war in the 19th century,” said de Anda in a press conference.
De Anda is also director of the Gran Acuifero Maya (GAM), a project dedicated to the study and preservation of the subterranean waters of the Yucatan peninsula.
The discovery was made thanks to a group of international divers led by German explorer Robert Schmittner, who has been researching the cave system for 14 years and are working along with the National Geographic Society.
On January 10, Schmittner was exploring the cave by himself when he felt a current coming from an opening. He took off his oxygen tanks for a moment so he could pass through it, connecting the Sac Actun system with Dos Ojos.
Schmittner and his team, composed by divers Marty O'Farrell, Jim Josiak and Sev Regehr, had been looking for the connection between both cave systems by diving into previously unexplored cenotes, and they suspect the cave is much bigger than what has been already confirmed.
“There are other caves around Sac Actun that might be connected. We're already close to the next one and they're probably linked. That other one is 18 kilometers long and is called 'The Mother of all Cenotes.' It goes 20 meters deep and is located north of Sac Actun. If so, the cave system would be longer than 500 km, and it seems to have no end,” said Schmittner.
He has referred to the cave system as an "enormous octopus" that probably is connected to other three systems.
De Anda also shows himself confident that new paths will be discovered. “We're certain it will grow. It will expand because the exploration is still going on and we're sure we will make an even bigger connection,” said the researcher.
Because of its archeological and environmental importance, the researching team is preparing a petition to enlist the cave system as a “Mixed Heritage” site protected by the UNESCO. The INAH and the Congress are supporting this initiative.
The cave system has not always been flooded, which allowed humans and extinct mammals from the Pleistocene to come in. When the last Ice Age ended almost 12 thousand years ago, the water levels rose 100 meters and flooded it, creating “ideal conditions for the preservation of the remains of extinct megafauna from the Pleistocene.”