With another skull in the background, veteran climber Pete Athans is seen recovering human remains from a severely eroded cliffside cave in Nepal's Mustang region last year (Mustang region map).
The 1,500-year-old bones are among the remains of 27 human corpses—many of which had been stripped of flesh—found in the human-made cave system. The findings point to a previously unknown Himalayan death ritual, the team announced Friday.
Because the caves—and the entire cliff face—are highly unstable, retrieving the remains could be done only by expert climbers.
Bioarchaeologist Jacqueline Eng of Western Michigan University catalogs the human remains found in the Mustang caves above the village of Samdzong last year.
More than a thousand years ago the corpses had been neatly laid to rest on wide wooden shelves, the researchers speculate. But due to centuries of exposure to the elements, the bones and their bunks had collapsed by the time the team entered the chambers.
Also in the jumble: goat, cow, and horse remains—perhaps sacrificial offerings for the dead, though their purpose remains a mystery.
Climber Matt Segal gently removes human remains from the interior of the cave system above Samdzong, Nepal.
In ancient times, rock outcrops and probably ladders would have eased access to the caves. Since then, however, erosion has rendered the chambers accessible to only expert climbers, such as Segal and Everest veteran Pete Athans, who co-led the team.
"Clues to when these caves were built, and by whom, are melting before our eyes," Athans said in a press statement. "The cave tomb we found is under great threat. It is situated in a fragile rock matrix that has already collapsed some time in the past. I don't believe the tomb would've lasted one more monsoon."
An ancient cave system—much like the one that held the newfound human remains—looms over the village of Drakkmar, Nepal, in the Upper Mustang region.
he new finds are only the latest signs of an ancient human presence in the remote cliffs, whose allure may have been heightened by their isolation, according to anthropologist Mark Turin.
"Monks can now practice and reside in monasteries, but we're talking about long before the establishment of any monastery," said Turin, director of the Digital Himalaya Project at the University of Cambridge.
Bioarchaeologist Jacqueline Eng (left) and archaeologist Mark Aldenderfer discuss a jawbone recovered from the cave tombs found in Nepal's Mustang region last year.
Aldenderfer and his team think the practice of defleshing corpses and entombing them in caves might be a previously unknown bridge between two other known death rituals: the later Tibetan sky burial and an earlier Zoroastrian practice of stripping corpses and feeding the flesh to animals.