🦂 The largest scorpion ever discovered: over a meter (3.3 ft) long

What was the largest land creature 415 million years ago? A scorpion over a meter long, far more imposing than any of its contemporaries. However, its existence was only confirmed recently, after more than a century of debate.

In the United Kingdom, fossils of Praearcturus gigas had been mistakenly attributed to a giant crustacean. Thanks to new analyses, scientists have finally proven it was indeed a scorpion. Its pincers measured 16 cm (6.3 in), and its body exceeded a meter (3.3 ft), making it the largest scorpion ever known.


This giant lived in the early Devonian, when life on land was in its infancy. It dominated the floodplains, hunting both on land and in water. According to Richie Howard, lead author of the study, this exceptional size is explained by the absence of large competing predators.

Identification was made possible thanks to a better-preserved fossil named Eramoscorpius, found in Canada. Like it, Praearcturus has an elongated sternum with a groove, a characteristic of scorpions. This anatomical detail removed all doubts.

Fossil fragments from Portishead suggest the species survived for at least 40 million years, but additional evidence is needed to unravel the mysteries of this extraordinary predator.

The colonization of land by arthropods

In the Devonian, life was slowly leaving the oceans. The first terrestrial arthropods were small, but some, like Praearcturus, reached gigantic dimensions. This phenomenon is explained by the absence of vertebrate predators on land.

However, these animals had to return to the water to feed or reproduce. Fossils show that Praearcturus had lateral expansions called epimers, similar to those of crabs, useful for swimming. Thus, it led an amphibious life.