Some of the mountainous areas in Battambang province’s Banan district – near the Kamping Puoy cave – are part of a 10km stretch of hundreds-of-million-year-old limestone, it has been discovered, thanks to the presence of fossils.

In May, a fossil hunting team from the Department of Heritage at the Ministry of Environment discovered many excellent examples in the area.

Experts identified several fossilised examples of marine life on a hill known as Phnom 150, including the remains of snails, coral and insects. Nearby, in Phnom Preah, they discovered fossilised coral and beehives. Some of the fossils were up to 50cm across.

In Ta Kream commune, Banan district – not far from the Kamping Puoy Reservoir – they uncovered fossils which are very similar to examples from the same area which are on display in museums in Vietnam. They were discovered during the French protectorate era and taken to Vietnam.

According to the geological map of Cambodia, some of the mountains in Battambang date back to the Permian period (251-299 million years) in the Paleozoic era. This was confirmed by Lim Vanchan, expert archaeologist with the heritage department.

“Our studies began in 2019. We wanted to gain a deeper understanding of the national history of the Kingdom, including the species that lived here millions of years ago. So far, we have identified 43 sites of archaeological interest. Each has different features. There are potential dinosaur fossils, along with those of marine and plant life,” he said.

Vanchan, who graduated with a bachelor’s degree in archeology from the Royal University of Fine Arts in 2001, said: “In our curriculum, we have primary studies which we excavate for research. Our preliminary goal is to locate fossil sites. Once we identify one, we generally carry out 10 days excavation. Additional investigations will be carried out later.”

The work to determine the age of the mountains of Cambodia has been ongoing for four years. Vanchan is lead on the expeditions.

He was initially employed at the Reyum Institute of Arts and Culture and then at the Ministry of Culture and Fine Arts, but has led the heritage department for the past eight weeks.

“This work is led by me. There are no foreigners involved. There are other teams involved, including cartographers and programme coordinators. I am also the first Cambodian to research the ancient animal fossils of the Kingdom. We have spent the last four years identifying new sites, so they can be protected for future generations of researchers,” he said.

He explained how he was able to determine the age of the mountains.

“Thanks to a geological map of Cambodia – and by the evolutionary stage of each of the fossilised creatures we find – we can gauge the age of the mountain range. To identify the evolution of the animals, we compare our findings with tables of what has been researched and published by different academics in the past,” he said.

“We published our initial findings in a book called ‘Pre-Biodiversity Fossil Records in Cambodia, first edition’ last year,” he added.