Sternomancy

Sternomancy, from the Greek sternon is a divination practice involving reading the markings or bumps on the chest or breast bone. Sternomancy may have been commonly practiced on victims of sacrifice, including human sacrifice. Sternomancy may also include speaking through the chest.
The size and shape of the sternum bone are taken into consideration, as well as the way in which the bone burns when placed into a fire. The old holiday custom of the breaking of a chicken's or turkey's wishbone by two persons is actually a remnant of this type of divination.
Sternomancy is related to phrenology, palmistry and scapulomancy.