Most of the bodies that have been found dating from prehistoric times have decayed just to bones - but they do give a few clues about what surgery might have been performed on our distant ancestors.
Australian aborigines in recent times were able to stitch up wounds and to set broken bones by encasing them in mud. Some historians suggest that this shows that prehistoric people could have acquired similar skills. The presence of healed but badly set bones in prehistoric graves, however, suggests that perhaps they had not.
Archaeologists have certainly found examples of trephined [Trephined: The removal of a round disk of bone, usually from the skull. ] (or trepanned) skulls in excavations of prehistoric sites. Historians have suggested that the motivation of these operations was medical, in so far as it was intended to remove an evil spirit which, for example, was causing epilepsy or headaches. This may be true, but cannot be proved.
The skull of Gadevang Man is a well-preserved, prehistoric 'bog body', dated 480-60 BC, found in Denmark. The skull shows signs of a surgical trephination procedure
The precise cuts that can be seen on some of the trephined skulls, and the re-growth of the bone (which proves that the patient/victim survived the operation), do indicate that prehistoric people had the ability and knowledge to be successful surgeons.