Archaeologists exploring the world’s biggest flooded cave in Mexico have discovered ancient human remains dating to at least 9,000 years ago, Reuters reported on Tuesday. They also found bones of animals who inhabited the earth during the last Ice Age.

A group of divers recently connected two underwater caverns in a cave system in eastern Mexico known as Sac Actun, near the beach resort of Tulum. The researchers found human remains, as well as bones of giant sloths, ancient elephants and extinct bears from the Pleistocene period, Mexico’s Culture Ministry said according to Reuters.

The Pleistocene period, the most recent Ice Age, began 26 lakh years ago and ended around 11,700 years ago.

Reuters said the discovery could help shed new light on the ancient Maya civilisation. Of the 200 archaeological sites researchers have discovered on the Yucatan peninsula, 140 are Mayan.

“I think it is overwhelming. Without a doubt it is the most important underwater archaeological site in the world,” Guillermo de Anda, researcher at Mexico’s National Anthropology and History Institute told the agency.