FOSSILS found near a border village have been identified as from the biggest ever scorpion to walk the Earth – the size of a large dog and thankfully 415 million years ago!

Its pincers measured more than six inches across and it was a metre long, according to experts from the Natural History Museum after an 18-year-long study of fossil fragments.

Evidence of the giant arachnid was found in the St Maughan's Sandstone – spanning Powys across to Worcestershire – including firstly at Rowlestone, three miles west of Grosmont, in 1871, plus Longtown in the Black Mountains and Tredmomen Quarry in Talgarth, near Brecon.

Named Praearcturus gigas, it was among the first large predators to stalk the land and was equally at home in water.

While fossils of the creature have been known about for more than a century, its identity was the subject of controversy until new research confirmed its status as one of the largest prehistoric scorpions, with the findings now published in the journal Palaeontology.

It would have towered over the treeless floodplains 415 million years ago, when life on land was still fairly new during the Early Devonian Period, meaning few other animals would have reached such sizes.

As a result, the giant scorpion would have had its pick of prey as it hunted small arthropods on land.

But Praearcturus would likely have been a fearsome aquatic predator as well, feeding on fish and other large animals.

Dr Richie Howard, the lead author of the study and the Natural History Museum's Curator of Fossil Arthropods, said: “When we think of giant arthropods, people tend to think of enormous millipedes like Arthropleura or the dragonfly-like griffinflies.

"But these species lived in the Carboniferous Period at least 55 million years after Praearcturus, once land-based ecosystems had time to develop.

“Instead, Praearcturus lived when life on land was just starting out and the ancestors of reptiles, mammals and birds were yet to leave the water.

"It suggests that this species might have grown so big because there weren’t any other large predators, allowing it to dominate its environment.

"Confirming that this animal is a scorpion fundamentally changes our understanding of how and when these creatures evolved to such extraordinary sizes."

Scientists used modern techniques and examined recently-documented fossil species in order to definitively establish Praearcturus was a scorpion.

The species was first discovered in Rowlestone some 10 miles north of Abergavenny in 1871 by English paleontologist Henry Woodward, although he thought it was a giant woodlouse-like crustacean rather than an arthropod.

This interpretation is still reflected in its name, as Arcturus is a group of living woodlice.

In the 1980s, scientists first started to suspect that Praearcturus might actually be a scorpion, boosted by the discovery of an ancient specimen called Eramoscorpius in Canada in 2015, which displayed internal structures almost identical to the local fossils.

“Without complex ecosystems to support Praearcturus on land, these animals probably spent part of their lives hunting in water,” Richie adds.

“Some of the fossils found in Wales show that they had flap-like structures known as epimera that are similar to those found in lobsters and crabs.”