Archeologists unveiled on Thursday (November 16) an ornate carving of an Aztec god they found that could be the massive headstone of one of the civilization's final rulers. The Aztecs, a warlike and deeply religious people who built numerous monumental works, ruled an empire encompassing much of modern-day central Mexico until they were overthrown by the Spanish in 1521. The 12.4 tonne stone slab, 46 feet (14 m) in surface area, is covered with a detailed full-body engraving of earth god Tlaltecuhtli. It is in excellent condition, despite being split in several places and scientists call it one of the most important Aztec findings ever. The deity is carved with a giant male head ringed by masses of curly hair and a sharp extended tongue representing a stream of blood. Around his body are skulls, crossed bones and a rabbit with several dots that researchers may date the sculpture to 1502. They say the monolith may be the headstone of Ahuizotl, the eighth ruler of Tenochtitlan, whose successor Moctezuma II ruled the Aztec empire at the start of the Spanish conquest of Mexico. The stone was found in Mexico City's Templo Mayor, a main Aztec temple used for human sacrifice, whose ruins are now steps from choking traffic hemming the city's traditional colonial centre.