 The head shape is wide and flat, with a seemingly “smiling” face created by the jaw closure.The skull lacks the epipterygoid bone (bone above the pterygoid extending to parietal bone) and parietal-squamosal contact but possesses an internal carotid canal and strong postorbital-squamosal contact.The mud terrapins are either semiaquatic or fully aquatic and typically walk on the floor of slow-moving waters.