The Collaborative International Dictionary of English v.0.48:

Supraoccipital \Su`pra*oc*cip"i*tal\, a. (Anat.)
   Situated over, or in the upper part of, the occiput; of or
   pertaining to the supraoccipital bone. -- n. The
   supraoccipital bone.
   [1913 Webster]

   Supraoccipital bone (Anat.), a bone on the dorsal side of
      the great foramen of the skull, usually forming a part of
      the occipital in the adult, but distinct in the young.
      [1913 Webster]