An artist’s impression of Jaekelopterus rhenaniae, a sea scorpion that lived approximately 390 million years ago and is one of the largest arthropods ever discovered.Credit...Ja Chirinos/Science Source
The New York Times Trilobites column has an interesting story about eurypterids. Previously, the giant sea scorpions of the Paleozoic were known to be apex predators, some growing quite large... 9 feet long or more. And, as if it couldn't get any more horrific, it seems that they could swim long distances, even crossing oceans. Research published in the journal Gondwana Research found they "effectively functioned as sharks" and "were absolutely pushing the limits of what we know arthropods could do".
What are commonly known as sea scorpions were a diverse group of arthropods called eurypterids. They came in many shapes and sizes but are perhaps best known for their largest representatives, which could grow to more than nine feet long. With huge claws, a beefy exoskeleton and a strong set of legs for swimming, the larger sea scorpions most likely ruled the seas.
However fearsome these arthropods must have been to Paleozoic prey, they went extinct without much of a bang. The fossil record of eurypterids peaked in the Silurian period, which started about 444 million years ago, and they then abruptly died out after the early Devonian period ended about 393 million years ago.That sudden turn of fate has left scientists bewildered.
“They appear, they start doing really well, they get very big, and then they go extinct,” said James Lamsdell, a paleobiologist at West Virginia University who was not involved in the study. “For a while they were so dominant, and then they just burned out.”
