Entry record from Roesler (2011): Central Asmat
biwnam
• star-shaped stone with a hole in middle, used in cannibal rituals.
Encyclopedic info: Hole said to come by itself. Hole is not used, one said. Is it possibly used for a handle? Or this hole may be put over the temple to break open the skull and work out the brains. Some skulls show a hole there.
Reference: 4.1216