A skeleton discovered at a ruined pyramid in Tlateloco in Mexico City February 10, 2009. Archaeologists have discovered a mass grave with four dozen neatly lined up human skeletons in the heart of Mexico City, revealing clues about the Spanish conquest that killed millions in battle and disease. The 49 bodies, all lying face up with their arms crossed over their chests, were discovered as investigators searched for a palace complex in the Tlatelolco area, once a major religious and political center for the Aztec elite. [Agencies]