Placodus had a stocky body with a long tail, and reached a total length of up to 2 metres (6.6 ft). It had a short neck, and a heavy skull. They were specialized for a durophagous diet of shellfish, such as bivalves. Chisel-like incisors protruded from the anterior margin of the snout, and were probably used to pluck hard-shelled benthic prey from the substrate. The back teeth were broad and flattened, and would have helped to crush the prey.[1] Before the animals' anatomy was known, they were regarded as fishes' teeth. Similar smaller teeth were present on the palatine bones.