Psephoderma

Psephoderma is a genus of placodonts very similar to the related genera Placochelys and Cyamodus. Psephoderma had a flattened skull and a narrow, straight rostrum, much narrower than that of its relatives. Inside this skull, embedded in the jaws, were rounded teeth specialized for crushing the shellfish it ate. Unlike henodontid placodonts, Psephoderma's carapace was divided into two pieces, one on the shoulders and back, and another on the ventral end. Psephoderma grew to 180 centimetres (5.9 ft) long, larger than many of its relatives, and lived in the Late Triassic, about 210 million years ago. It was one of the last placodonts to live. Fossils of Psephoderma have been found in the Rhaetian deposits in the Alps and in England, hence the specific names.