A () or skull rack was a type of wooden rack or palisade documented in several Mesoamerican civilizations, which was used for the public display of human skulls, typically those of war captives or other sacrificial victims. It is a scaffold-like construction of poles on which heads and skulls were placed after holes had been made in them. Many have been documented throughout Mesoamerica, and range from the Epiclassic () through early Post-Classic (). In 2017 archeologists announced the discovery of the Hueyi Tzompantli, with more than 650 skulls, in the archeological zone of the Templo Mayor in Mexico City. Etymology The name comes from the Classical Nahuatl language of the Aztecs but is also commonly applied to similar structures depicted in other civilizations. Its precise etymology is uncertain although its general interpretation is 'skull rack', 'wall of skulls', or 'skull banner'. It is most likely a compound of the Nahuatl words ('skull'; from or 'hair', 'scalp' and ('gourd' or 'container'), and ('banner'). That derivation has been ascribed to explain the depictions in several codices that associate these with banners; however, Nahuatl linguist Frances Karttunen has proposed that means merely 'row' or 'wall'. Historical distribution General information It was most commonly erected as a linearly-arranged series of vertical posts connected by a series of horizontal crossbeams. The skulls were pierced or threaded laterally along these horizontal stakes. An alternate arrangement, more common in the Maya regions, was for the skulls to be impaled on top of one another along the vertical posts. are known chiefly from their depiction in Late Postclassic (13th to 16th centuries) and post-Conquest (mid-16th to 17th centuries) codices, contemporary accounts of the conquistadores, and several other inscriptions. However, a -like structure, thought to be the first instance of such structures, has been excavated from the Proto-Classic Zapotec civilization at the La Coyotera, Oaxaca site, dated from around the 2nd century BCE to the 3rd century CE. The Zapotecs called this structure a , and it displayed 61 skulls. are also noted in other Mesoamerican pre-Columbian cultures, such as the Toltec and Mixtec. Toltec At the Toltec capital of Tula exists the first indications in Central Mexico of a real fascination with skulls and skeletons. Tula flourished from the ninth until the thirteenth century. The site includes the decimated remains of a . The at Tula displayed multiple rows of stone carved skulls adorning the sides of