Based on ethnohistorical, archaeological, chemical, and metallurgical analyses, the scholars Hosler, Lechtman and Holm have argued for their use in both regions (which are separated by thousands of miles) through trade.
The form and method of creating interlocking metal rings is identical in the two traditions, and even their archaeological context (placed around the cranium in burials) is remarkably similar.
However, the wax-casting tradition of the Intermediate Area, which spread to other parts of Mesoamerica, also proved influential in the western Mesoamerican context, such as in the creation of copper-gold alloy bells.
[8] It is known through early Spanish accounts that native Ecuadorians used balsa rafts fitted with sails to travel along the northern Andean coast to trade.
Furthermore, contemporary accounts from the Balsas River in western Mexico report that the fathers and grandfathers of local men had traded with canoe-borne traders, who sometimes spent as long as half a year in the area.
[9][10] This trading system was therefore ancient; it is suggested by Dewan and Hosler that these traders operated along the Andean coast from Colombia in the north to Chile in the south as early as 100 BCE.