"This thing was like Fort Knox," said Brown University archaeologist Stephen Houston, who led the excavation in the ancient, overgrown Maya town of El Zotz.

Alternating layers of flat stones and mud preserved human bones, wood carvings, textiles, and other organic material to a surprising degree—offering a rare opportunity to advance Maya archaeology, experts say.

"Since [the artifacts] appear in a royal tomb, they may provide direct insights in the political economy of the divine kings that likely involved tribute and gifts," Vanderbilt University anthropologist Markus Eberl, who was not involved in the project, said via email.

Excavation leader Houston added, "we're looking at a glimpse of lost art forms."

(Pictures: what the Maya Empire looked like.)

The researchers found grisly deposits