Giant scorpions are not just something out of mythology or fantasy, they actually lived on this planet and the biggest has been discovered. Say hello to Jaekelopterus rhenaniae.

This creature lived on earth about 390 million years ago, and is of the Arthropod family—the same family that includes spiders, scorpions and centipedes. What sets this sea scorpion apart from his brethren is that he grew to be larger than a full grown man. Scientist unearthed one of Jaekelopterus rhenaniae‘s claws and the claw itself measured 18 inches long, which makes scientists estimate it’s size at over 8 feet long. That’s about the size of a large crocodile.

The Diet of a Giant Sea Scorpion

Jaekelopterus rhenaniae terrorized coastal swamp waters feeding on fish, by ambushing them with its almost spring-loaded arms, then slicing them up with it’s spiked claws that were capable of holding onto even the most slippery of fish. Jaekelopterus rhenaniae didn’t just feed on fish, it was also a known cannibal. J. rhenaniae was the top predator of it’s day and conquered it’s swampy landscape with no challenge from any other animal. The sea scorpion’s dominance of the food chain, might have even been the reason some fish of the era evolved bony shields to help them survive against attacks from the massive sea scorpion!

Massive Size Helped Lead to the Creature’s Demise

Scientists have long known about our planet’s sordid past filled with giant horrifying insects and arthropods, but according to paleobiologist Simon Braddy of the University of Bristol in the United Kingdom (a member of the team who discovered the fossilized claw in a German Quarry near the city of Prum,) it’s the first time they’ve ever discovered one this gargantuan! The second biggest fossil of an arthropod found is that of a 6 foot long giant millipede. While J. rhenaniae sat frighteningly at the top of it’s food chain, it wasn’t a flawless design by mother nature at all. In fact, it’s legs were so frail that they would snap on land without the aid of buoyancy in water against the creature’s massive body weight.

How Did Jaekelopterus Rhenaniae Get So Big?

J. rhenaniae and it’s family members were hypothesized by some in the scientific community to have reached such epic proportions simply because no other creature could challenge it. Fish hadn’t developed jaws, and other vertebrates hadn’t yet began to evolve ways to defend against these highly adapted sea scorpions and challenge them for food. Others in the scientific community believe that the increased levels of oxygen in the atmosphere could be what fueled the growth of these massive arthropods. These creatures were wiped out during the largest mass extinction of sea life in history about 250 million years ago and their closest relatives could not compete against the new breed of larger vertebrate predators. This forced various arthropods to shrink in size and eventually move to land! The largest arthropods on our planet today are lobsters and spider crabs which are only a fraction of the size of Jaekelopterus rhenaniae.


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