Giant scorpions may have terrorized the seas some 460 million years ago.
The species of sea scorpion, Pentecopterus decorahensis, stretched up to 1.7 meters long — almost as long as a twin-sized bed. Scientists unearthed more than 150 fragmentary remnants from the sandy shale of an impact crater in what is now Iowa.
The sea predator may have used its forelimbs to capture prey and its paddlelike hind limbs to swim or dig, Yale University paleobiologist James Lamsdell and colleagues report September 1 in BMC Evolutionary Biology. Pressed between layers of rock for hundreds of millions of years, the specimens lay so well preserved that researchers could make out very fine hairs bristling from the scorpion’s underside.
Pentecopterus is the earliest sea scorpion yet discovered, edging out the previous record holder by some 9 million years.