If you’ve ever found yourself playing Fallout: New Vegas and thanking your lucky stars that you don’t live in a world infested with gigantic scorpions, well, I hate to break it to you, but you do. Or at least, you used to. According to new research published in the journal Palaeontology and led by Richard Howard of the Natural History Museum, scientists have confirmed that a massive scorpion once crept across what is now England and Wales.

Praearcturus gigas, as it’s called, lived around 415 million years ago during the Early Devonian period. Fossil fragments pulled from the St Maughan’s Sandstone Formation show a predator with 16-centimeter pincers and an estimated body length of nearly one meter, or roughly three feet. A scorpion as long as a toddler is tall. This would make it the largest scorpion ever identified in the fossil record.

No Way That Massive Thing Is a Scorpion, Scientists Thought

The fossils themselves have been sitting in museum collections since the 1870s, mystifying scientists for almost 200 years before people started to figure out what they actually were. A lot of the early researchers figured it was a scorpion, but dismissed those theories since the incomplete remains looked a bit more like the remnants of a giant crustacean.

Modern CT scanning and 3D modeling tech, paired with some better-preserved scorpion fossils that were found in Canada back in 2015, suggested that its triangular sternum made it much more likely to be a scorpion.

Creatures that historically have existed in higher oxygen environments tend to be bigger. But the Praearcturus lived at a time before the world was covered in sheets of forests that pumped oxygen into the atmosphere. In its time, it was mostly surrounded by small plants and fungi. So, how did he get so big? Researchers think that probably had more to do with there being fewer predators, allowing it to take up that space by growing larger.

Some of the fossils suggested it might’ve split its time between land and freshwater, which makes sense considering this was an era of land-dwelling creatures experimenting with being landlubbers.