Stegosauria is the suborder to which only stegosaurs belong and it is represented by the basal member Huayangosaurus which shares the following characteristics with the more derived members of the stegosaurs and is distinguished from other Eurypoda. They all have a large oval cavity on the palatal part of the quadrate; back vertebrae with very tall neural arches with highly angled transverse processes; loss of the first digit of the foot; loss of one of the toe bones of the second digit; formation of long spines of plates from the shoulder toward the tip of the tail; a parascapular spine; loss of ossified tendons down the back and tail; a broad and plate-like flange on the forward surface of the shoulder blade; large block-like wrist bones; and an elongation of the prepubic process on the pubic bone.