Instead of blood, 7 serpents sprout from where his head was removed. Seven serpent was also the name of the god of ripe corn. The harvest of corn was symbollicaly like beheading; the former to feed humans, the latter to feed the gods.
They dug up a pyramid "Las Higueras" with original frescoes depicting mythological scenes, ceremonies and ball games. In ancient Mesoamerica it was thought that there was a chance the world might end once every 52 years. So whenever it did not, they would add a new level onto their pyramids to make them more grandiose. The result is that the layers of murals show 3 centuries of changing beliefs and artistic styles.