In the heart of Thailand, a discovery of ten newly identified trilobite species, hidden for an astounding 490 million years, has opened a door to unraveling an ancient map of Earth’s geography. Trilobites, with their distinctive half-moon-shaped heads, once thrived as sea creatures during the late Cambrian period.

Found in the northern outskirts of Mexico City, the trilobite fossils were entombed in layers of petrified ash in sandstone, remnants of ancient volcanic eruptions that created a layer known as a tuff.

These tuffs, containing resilient zircon crystals formed during eruptions, provide a unique opportunity for dating fossils and understanding the Earth’s history.

Nigel Hughes, a geology professor at UC Riverside and co-author of a 100-page monograph detailing the discovery, explains the rarity of finding tuffs from the late Cambrian period, a period between 497 and 485 million years ago.

The dating of these fossils not only sheds light on the ancient Thai region but also offers insights into parts of the world like China, Australia, and North America, where similar fossils exist in rocks that are challenging to date.

The fossils, discovered on the coast of Ko Tarutao, an island about 40 minutes southwest of Thailand’s mainland, connect the region to other parts of the world, particularly Australia. During the trilobites’ existence, this area was on the outer fringes of Gondwanaland, an ancient supercontinent comprising Africa, India, Australia, South America, and Antarctica.

The discovery includes a species named in honor of Thai Royal Princess Maha Chakri Sirindhorn. Apart from the scientific significance, the fossils contribute to piecing together the puzzle of Earth’s ancient geography as continents shifted over time. As Hughes describes it, researchers are engaged in solving a “moving, shape-shifting, 3D jigsaw puzzle.”

The trilobite discovery encapsulates a chronicle of evolutionary change and extinctions, providing a valuable record for understanding the present-day changes on Earth. The fossils offer a unique glimpse into the intricate history of our planet, allowing scientists to decipher the Earth’s ancient landscapes and the remarkable creatures that once inhabited them.