Snail shell.
According to the first interpretation the carving on the seashell represents the end of the war that is resolved through the exchange of prisoners between the two ruling lords who are again sitting on thrones facing each other. The character on the right has a plant in his hand, wearing a headdress ornaments and has fierce face with open mouth showing teeth. The character on the left is carrying two individuals, one under his right arm and the other on his shoulder; it has a headdress shaped like a bird and ornaments crest and like the previous one, has a fierce face showing teeth. Above both characters the plumed serpent with a forked tongue witnesses the agreement.