Wiwaxia

Wiwaxia is a slug-like creature whose top surface was covered with leafshape ribbed plates (sclerites) and two rows of longer spines. These are often preserved as a flattened mass of armour, which hides the details of the soft tissue. Occasionally a radula bearing two rows of teeth is seen at the anterior (head) end of the organism. Wiwaxia has been considered a polychaete (bristle worm), but this interpretation is controversial. It crawled along the sea floor, feeding on organic detritus.