Gigantic scorpions with formidable pincers over 16 centimetres long once roamed the floodplains of England and Wales, a new fossil study reveals. The metre-long scorpion, named Praearcturus gigas, is the largest of its kind ever to have existed, according to researchers from the University of Manchester.
The species was identified based on fossils from the St Maughan’s sandstone geological formation in Wales. It lived during the Early Devonian period, approximately 415 million years ago, when small plants and fungi had just begun to spread, and complex land ecosystems like forests had yet to emerge. This was a time well before the evolution of trees, when life on land was only just getting started, scientists say.
Fossil History and Identification
The species was identified using a fossil specimen held in the Natural History Museum’s collection for more than 150 years, which had puzzled scientists for over a century. Originally thought to be a giant crustacean, similar to a woodlouse, due to the fragmentary nature of the fossils lacking key features such as a tail for over 100 years, better-preserved fossils discovered in recent years and advanced analytical techniques have now revealed that the fossils belong to a distinct scorpion species.
“Confirming that this animal is a scorpion fundamentally changes our understanding of how and when these creatures evolved to such extraordinary sizes,” said Richard J Howard, lead author of the study published in the journal Palaeontology. “By bringing together material from several collections and using cutting-edge imaging techniques, we've been able to build a clearer picture of the animal than was previously possible,” said Russell Garwood, a palaeontologist at the University of Manchester.
Life and Environment
The scorpion lived at a time when life on land was otherwise very small. To reach such extraordinary sizes, researchers suspect it may have partly lived in water, where life was bigger. It might have grown so large because there were not many competitors of such size on land. Fossils indicate it had flap-like structures on the abdomen – similar to those found in modern crustaceans like lobsters – that may have enabled it to move between water and land.
“The boundary between land and sea was much less defined at this time. Praearcturus gives us a fascinating glimpse into how early animals adapted to these changing environments,” said study co-author Greg Edgecombe from the Natural History Museum. “Specimens collected over a century ago can still hold entirely new insights. By revisiting them with modern techniques, we can uncover discoveries that reshape our understanding of life on Earth,” Dr Howard added.
