A newly discovered temple complex in the Valley of Oaxaca, Mexico, reveals hints of a specialized hierarchy of priests -- who may have committed human sacrifice... The temple dates back to 300 B.C. or so, when it was in use by the Zapotec civilization of what is now Oaxaca. Archaeologists have been excavating a site in the valley called El Palenque for years. The site is the center of what was once an independent mini-state. Between 1997 and 2000, the researchers found and studied the remains of a 9,150-square-foot (850 square meters) palace complex complete with a plaza on the...