These eurypterids were about six feet in length with a long head and a sleek body .Photo by Patrick Lynch, Yale University
Ok. It is not really a scorpion but the artist’s rendition of this most unusual eurypterids (an extinct group of chelicerates) looks a heck of a lot like the terrestrial arachnids of today. The sea scorpion, Pentecopterus decorahensis, was described in the journal BMC Evolutionary Biology, and like its terrestrial namesake, is a carnivore, but has more in common with the horseshoe crab than the arthropod of the Scorpiones order.
Photo by Patrick Lynch, Yale University
Pentecopterus was probably intimidating during its time, and if humans were around, they might have thought twice about swimming in the sea. These eurypterids were about six feet in length with a long head and a sleek body. They sported large appendages with inward pointing spines that were perfect for grasping and holding prey. The animal lived more than 467 million years ago. They were discovered in an Iowa fossil bed in the Upper Iowa River in 2010 and just described in 2015.
The paper describing the sea scorpion, Pentecopterus decorahensis was published today. You can read it at BMC Evolutionary Biology.