Archaeologists in Mexico City made a grisly and awesome discovery this week, after a subway extension project uncovered a stretch of pre-Hispanic development—including four skulls that were once displayed on a broad rack of bones from sacrificial offerings.


Scientists from Mexico's National Institute of Anthropology and History estimate that the newly-discovered skulls date roughly from 1350 to the 1520s, a period of history that begins before the arrival of Spaniards in Mexico and ends with their successful conquest in 1521. According to the archaeologists, the skulls were part of a structure called a Tzompantli, which translates roughly to "skull banner," a rack where skulls (sometimes many thousands of them) taken from ritual sacrifice victims would be stored and displayed.




The find uncovered two male skulls, one female skull, and one dog skull—which is the most surprising, as tzompantli were traditionally made only from human skulls. Only a few deviations from that rule have ever been discovered, including horse skulls that were racked alongside their Spanish riders in the early 1500s.

Images: DSA-INAH.

PhysOrg speculates that the skull rack might have included non-ritual victims, too, including women and dogs, that were considered important guardians on the journey into the afterlife. Along with the skulls, the dig team also uncovered sculptures, dwelling sites, and more traditional burials:


Image: DSA-INAH.

This is far from the first time subway excavation has hit human remains—although it might be the spookiest. In October, tunnel diggers working on London's latest subway expansion discovered 20 skulls of people who might have died during the Boudicca rebellion in AD 60, when Celtic tribes rose up against Roman occupation. In the same month, construction workers building an oil pipeline in Saskatchewan uncovered the remains of humans who far predate Europeans in North America.


It's strange to think that our knowledge of the ancient past depends largely on accidental discoveries like these, precipitated by roadway construction projects and subway digs. Who knows what else we'll find buried below our feet in the decades to come, as we hungrily expand the web of subterranean infrastructure outside the boundaries of today's cities? [PhysOrg]