The immense fossilised claw of a 2.5m-long (8ft) sea scorpion has been described by European researchers. The 390-million-year-old specimen was found in a German quarry, the journal Biology Letters reports. The creature, which has been named Jaekelopterus rhenaniae, would have paddled in a river or swamp. The size of the beast suggests that spiders, insects, crabs and similar creatures were much larger in the past than previously thought, the team says. The claw itself measures 46cm - indicating its owner would have been longer even than the average-sized human. Overall, the estimated size of the animal exceeds the record for any other sea scorpion (eurypterid) find by nearly 50cm. The eurypterids are believed to be the extinct aquatic ancestors of modern land scorpions and possibly all arachnids (the class of animals that also includes spiders). "The biggest scorpion today is nearly 30cm so that shows you how big this creature was," said Dr Simon Braddy from the Universi