 The region of the pterygoid (another of the palatal bones) that borders the quadrate is squared off.The interpterygoid vacuity (a region enclosed by the left and right pterygoids) is separated into the anterior and posterior interpterygoid vacuities, the former of which is particularly large.The parasphenoid (one of the bones in the braincase) runs over the midline of the narrower posterior interpterygoid vacuity.