-petros-

a. [ See Petrous. ] (Anat.) (a) Hard; stony; petrous; as, the petrosal bone; petrosal part of the temporal bone. (b) Of, pertaining to, or in the region of, the petrous, or petrosal, bone, or the corresponding part of the temporal bone. [ 1913 Webster ]

Petrosal bone (Anat.), a bone corresponding to the petrous portion of the temporal bone of man; or one forming more or less of the periotic capsule. [ 1913 Webster ]