Prickly Slug Fossil.

Paleontologists discovered fossils of a slug-like creature covered with prickly armors that lived on the ocean floor about 500 million years ago:

Called Orthrozanclus reburrus, the new animal was about half the size of a potato bug (called a garden pill bug by some) and had a front shell and long spines covering its entire body with a border of shorter spines along the edges …

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See also: World’s Strangest Dinosaur Names