Azernews.Az

By Alimat Aliyeva

The Saudi Royal Commission for AlUla announced on Thursday the discovery of horseshoe crab fossils dating back approximately 465 million years, Azernews reports, citing foreign media.

The discovery was detailed in a peer-reviewed study published in Gondwana Research, a leading international journal in geological sciences, according to the Saudi Press Agency.

The fossils were unearthed in the AlGharameel Nature Reserve in AlUla, located in northwest Saudi Arabia. They date to the Ordovician period (approximately 485–444 million years ago), making them among the oldest horseshoe crab fossils ever discovered worldwide.

Notably, the fossils are exceptionally large compared to other specimens from the same era. Remarkably, all fossils were found preserved upside down, a mode of preservation never previously recorded. Alongside them were trace fossils showing attempts by the animals to right themselves, providing rare insights into ancient behavioral patterns.

Geological analysis suggests that these organisms lived in shallow coastal environments subject to intense seasonal storms, which likely contributed to their unique preservation in sedimentary deposits.

Experts say the discovery offers an unprecedented glimpse into the behavior and ecology of early marine life. “It’s not just the age and size that make these fossils extraordinary, but also the story they tell about the challenges these creatures faced hundreds of millions of years ago,” said one paleontologist involved in the study.

The finding also highlights AlUla’s significance as a window into Earth’s deep past, supporting ongoing efforts to develop the region as a hub for geological research and heritage tourism.