Overview
- The study, published on Wednesday 3 June 2026, formally identifies Praearcturus gigas as a scorpion about one metre long and the largest known scorpion species.
- Researchers re-examined fragmentary specimens held at the Natural History Museum together with newer fossils using X-ray tomography and comparative anatomy to reunite and reclassify the material.
- Fossil anatomy includes very large pincers with fixed and movable fingers, a stridulatory surface, a scorpion-like sternum, and flap-like abdominal appendages that suggest some aquatic ability.
- Because Praearcturus lived in Early Devonian floodplain and freshwater settings before forests and high atmospheric oxygen, the authors argue its size likely reflects ecological opportunity and partial water use rather than oxygen-driven gigantism alone.
- Specimens attributable to the species come from several UK sites including Herefordshire, Worcestershire and Tredomen Quarry in Wales, and the revision highlights the research value of long‑held museum collections and interdisciplinary imaging methods.