Diplocaulus had a stocky, salamander-like body, but was relatively large, reaching up to 1 metre (3.3 ft) in length. Its most distinctive features were the long protrusions on the sides of its skull, giving the head a boomerang shape.Judging from its weak limbs and relatively short tail, it is presumed to have swum with an up-and-down movement of its body, not unlike cetaceans today. The wide head could have acted like a hydrofoil, helping the creature glide through the water. The University of Michigan's exhibit takes this concept on step further, adding a sheet of loose skin from the tips of the skull to the base of the tail which would have moved in an undulating wave for forward motion. Another possibility is that the shape was defensive, since even a large predator would have a hard t