This photo at first appears to be of an odd creature resembling a sea scorpion, or a eurypterid, which have been extinct for about 200 million years. It was for a time even displayed on various sites as a strange new cryptid that was found, according to the ‘story,’ by farmer Ted Litton in 1971. It is, however, a fake, and is in fact an animatronic prop from the BBC televesion series ‘Sea Monsters.’ It was modeled after the Megalograptus, one of the earliest eurypterids known.
Eurypterids (from the Greek word eury- meaning “broad” or “wide” and the Greek word pteron meaning “wing”) are an extinct group of arthropods related to arachnids which include the largest known arthropods that ever lived. Eurypterids predate the earliest fishes. The largest, such as Jaekelopterus, reached 2.5 metres (8 ft 2 in) or more in length. They were formidable predators that thrived in warm shallow water, in both seas and lakes.