Timeline of Life in Cambodia | From Permian Seas to Dinosaurs

When most people think of Cambodia, their mind jumps to Angkor Wat or the rich heritage of the Khmer Empire. But beneath the surface lies a much older story—hundreds of millions of years old. It’s a story told not through stone temples, but through the fossils embedded in ancient rock formations, waiting to be discovered.

Cambodia’s deep past has remained mostly hidden until recent years. But thanks to new research and local discoveries, scientists are now beginning to uncover the incredible timeline of life that once thrived here—from warm tropical seas to forests filled with dinosaurs.

Life in the Permian Period (299–252 Million Years Ago)

The journey begins in the Permian period, when Cambodia was a very different place. Back then, large parts of the country were covered by shallow tropical seas, much like the coral reefs we see in modern-day Thailand.

Fossils found in northwestern provinces like Banteay Meanchey and Battambang have revealed rich marine life from that time. In limestone hills like Phnom Svay and Phnom Bak, scientists have found corals, brachiopods, fusulinids (tiny shelled organisms), and even ammonites – ancient cousins of today’s squid.

But it wasn’t just sea life. In the Kang Va Mountains, researchers found petrified wood, dating back over 250 million years. That means forests of large trees grew near these oceans. It’s likely that islands with dense vegetation existed along the ancient coast, with trees occasionally falling into rivers and becoming fossilised after being buried in sediment.

So the Permian Cambodia was a place of reefs and coastal forests, a mix of land and sea where life thrived in very warm, humid conditions.

The Triassic Period (252–201 Million Years Ago): Oceans Retreat

Moving into the Triassic period, the planet was recovering from the largest extinction in history. In Cambodia, some areas remained under shallow seas, especially in the north, where ammonite fossils have been found in the Rovieng district of Preah Vihear province.

These spiral-shaped fossils are a clue that marine life was still present. But at the same time, the seas were beginning to retreat. Tectonic forces were reshaping the region, creating river plains and coastal lagoons. This shift left behind red sandstones and siltstones—known as “red beds”—which tell us that rivers were now cutting across the land.

Sadly, there’s not a lot of fossil evidence from this period. No bones, no footprints—at least not yet. But based on what’s been found in neighboring countries, we can guess that early dinosaurs and reptiles might have begun to appear in Cambodia’s changing landscapes. The lack of fossils doesn’t mean they weren’t there, only that we haven’t found them.

Jurassic Period (201–145 Million Years Ago): Oceans Return, Forests Expand

The Jurassic period is often thought of as the “Golden Age of Dinosaurs”, and it’s quite likely they roamed Cambodia too—though we haven’t yet found their bones from this time.

But we have found something else. In the Sre Pok River Valley near the Vietnamese border, ammonite fossils dating to the Middle Jurassic have been discovered. This confirms that, once again, Cambodia saw a return of marine conditions, at least in parts.

In other areas, especially in the west and southwest, rivers and forests dominated. Thick layers of sandstones and conglomerates were laid down by ancient rivers, forming what would later become fossil-rich zones. These were ideal environments for dinosaurs, but their fossils haven’t turned up yet.

That said, reports of possible dinosaur footprints in Battambang province have sparked interest, though no official confirmation has been made. Perhaps with more fieldwork, the Jurassic dinosaur story of Cambodia will be told more fully.

Cretaceous Period (145–66 Million Years Ago): The Age of Dinosaurs in Cambodia

It’s in the Cretaceous that Cambodia’s prehistoric life truly comes to light. By this period, the landscape was filled with rivers, swamps, and thick forests. Huge sediment layers known as the Grès Supérieurs (Upper Sandstones) were deposited across Kampot, Koh Kong, and other provinces.

In 1972, fossil plants including ferns and petrified conifer wood were found in the Bokor sandstone formation. Later studies confirmed they were from the Early Cretaceous. This suggested a warm, wet environment with lush plant life—ideal for large herbivorous dinosaurs.

The biggest breakthrough came in 2021, when a 70-centimetre-long dinosaur leg bone was found on Koh Paur Island in Koh Kong province. It turned out to be the first confirmed dinosaur fossil in Cambodia. The bone belonged to a sauropod—a giant, long-necked, plant-eating dinosaur that probably roamed the region’s floodplains.

This discovery changed everything. Cambodia was no longer a blank space on the dinosaur map of Asia.

Besides the Koh Kong find, researchers have identified dinosaur-like footprints and fossil leaf imprints in other provinces like Preah Vihear and Battambang. Pieces of petrified wood—some more than 3 metres long—have been unearthed in different sites across the country, adding to our understanding of the ancient forest ecosystems.

These discoveries suggest that Cretaceous Cambodia was a vibrant landscape of forests, rivers, and roaming dinosaurs.

Fossil Hotspots: Where Ancient Life is Found

Some of the most significant fossil locations in Cambodia include:

• Sisophon, Banteay Meanchey – Rich Permian marine fossils and petrified wood
• Rovieng, Preah Vihear – Triassic ammonites
• Bokor Hill, Kampot – Early Cretaceous flora and pollen
• Koh Paur Island, Koh Kong – Cambodia’s first dinosaur fossil
• Phnom Prampi, Battambang – Fossils and possible dinosaur trackways
• Sre Pok River Valley – Jurassic ammonites

These sites are slowly being mapped and protected, with growing interest in creating educational parks and exhibits.

Also read, Cambodia Discovers 67 Fossil Sites in 13 Provinces, Including Its First-Ever Dinosaur Bone

A New Frontier for Science and Tourism

For many years, Cambodia lagged behind its neighbors in fossil research. Conflict, lack of resources, and difficult terrain slowed progress. But in the past few years, the tide has turned.

The Ministry of Environment, working with international experts, has launched an ambitious fossil research program. As of 2025, 67 fossil sites have been identified across 13 provinces. This includes fossils of marine invertebrates, petrified forests, dinosaur bones, and even Ice Age mammal remains.

There’s a real opportunity here—not just for science, but for tourism, education, and national pride. Imagine a dinosaur trail in Koh Kong, or a fossil forest park in Banteay Meanchey. Cambodia’s deep-time heritage could become a source of wonder for locals and visitors alike.

Final Thoughts

Cambodia’s ancient life story is just beginning to be told. From coral-filled oceans to dinosaur-filled floodplains, the country holds a timeline stretching back 300 million years.

What makes this timeline so exciting is that it’s still being written. Every fossil discovered adds another chapter. And while the Kingdom is best known for its temples, its oldest history is written in stone beneath the ground—waiting to be brought to light.

As exploration continues, one thing is clear: Cambodia was never just a land of empires. It was, long before that, a land of life.