Villagers in Chu Gu Commune of Krong Pa found the 30 oddly shaped mounds scattered over 100-square-meters along the Ba River in June, each 20-30 cm in diameter.
Some mounds remain intact, with others badly eroded.
While locals believe them to be relics from the ancient Cham Kingdom that stretched from Vietnam’s central coast into modern-day Cambodia and Laos, experts have another theory.
Hanoi-based La The Phuc, former director of the Geological Museum of Vietnam, said judging from the photos sent him by Gia Lai authorities, the mounds are fossils of the ammonite, a group of extinct marine mollusk.
"It is a soft-bodied snail with a hard shell that used to live on the continental shelf. Ammonite fossils normally date back 150-200 million years," he said.
Around 30 round mounds suspected to be ammonite fossils lie scattered along a river bank in Gia Lai Province. Photo by VnExpress/Quang Tue. |
Alongside other experts, he believes the mounds have only now been exposed due to river bank erosion.
The southern part of the Central Highlands used to be ocean which, after receding, left scores of trapped and compressed creatures to fossilize deep underground, they explained.
Working at the UNESCO Dak Nong Geopark, located in the Central Highlands province of Dak Nong, Phuc himself had discovered many ammonite fossils.
"At the end of this year, I will travel to Gia Lai to determine whether the mounds indeed fossilized ammonites and how long they had been trapped there."
Nguyen Quang Tue, head of the cultural heritage management office under Gia Lai’s Department of Culture, Sports and Tourism, said authorities would protect the mounds and prevent all access to their location pending further research.
Aside from Dak Nong Province, ammonite fossils have also been found in Cao Bang Province in northern Vietnam.