Archaeologists in southern Mexico announced Monday they have discovered a 2,700-year-old tomb of a dignitary inside a pyramid that may be the oldest such burial documented in Mesoamerica. The tomb held a man aged around 50, who was buried with jade collars, pyrite and obsidian artifacts and ceramic vessels. Archaeologist Emiliano Gallaga said the tomb dates to between 500 and 700 B.C.