What makes you think they were used for surgery?
We have found traces of cuts on skulls in a nearby graveyard. Out of around 700 skulls, 14 have these marks. They could only have been cut with a very sharp tool. At this time, 4000 years ago or more, it could only have been an obsidian blade. The cut marks show that a blade was used to make a rectangular opening all the way through the skull. We know that patients lived at least two to three years after the surgery, because the skull has tried to close the wound.
Have you uncovered any clues to why this surgery was performed?
There seem to be three main reasons. The first is to relieve the pressure of a brain haemorrhage; we found traces of blood on the inside of some of the skulls. The second is to treat patients with brain cancer, as we can see pressure traces from the cancer inside some of the skulls. And the final reason was to treat head injuries, which seem to have been quite common. The people of Ikiztepe got their copper from mines in the local mountains, and we think they had to fight other local people for access to it.