Royal Commission for AlUla documents 465-million-year-old horseshoe crab fossils

The Royal Commission for AlUla announced a peer-reviewed publication reporting rare horseshoe crab fossils from the Middle Ordovician, about 465 million years old, found at AlGharameel Nature Reserve; a follow-up research phase is planned for the first half of 2026.

The Royal Commission for AlUla has announced the documentation and international publication of rare horseshoe crab fossils discovered at AlGharameel Nature Reserve. The fossils are dated to the Middle Ordovician, about 465 million years ago, and were described in a peer‑reviewed paper in Gondwana Research. Researchers report the specimens are unusually large for the period and were preserved upside down, with trace fossils showing attempts to right themselves. The work was carried out in collaboration with an international team and the specimens have been placed in RCU's museum collections. Known details: - The discovery was published in Gondwana Research and released internationally for the first time. - Fossils date to the Middle Ordovician (approximately 485–444 million years ago) and are reported as about 465 million years old. - All specimens were found preserved upside down, with associated trace fossils indicating efforts by the animals to return to an upright position. - Geological stratigraphic analysis reported signs of repeated intense seasonal storms and shallow coastal conditions that likely contributed to the fossils' preservation. - The fossils appear to represent a previously unclassified species and were studied in collaboration with a team led by Dr Russell Bicknell of Flinders University. - The specimens are held within the Royal Commission for AlUla's museum collections for future research and public engagement. Summary: The find offers new information about AlUla's ancient coastal environment and adds material for ongoing paleontological research. A second phase of the study is scheduled for the first half of 2026 to collect more samples and to prepare the new species for formal scientific classification.