Sea scorpions roamed the ancient ocean 500 million years ago. They were kind of like a cross between a horseshoe crab and a scorpion, and could grow to be the size of a crocodile. But these fearsome creatures might have something in common with Victorian ladies and hermit crabs – they might have worn hats (or pants, depending on your perspective) made out of other animals.
Based on uneven sea scorpion tracks, researchers figured out that sea scorpions must have been carrying weight on their left side. From National Geographic:
The odd drag marks could have been from the coiled shells of snails or similar critters, which the ocean-dwelling scorpions stuffed their tails into so they could venture above water, the researchers suggest.
Humid air trapped inside the shells might have protected the sea scorpions’ gills from drying out during brief forays into the open air—like reverse scuba gear.
No word on whether they went shopping with the helmet-shrimp.