his team collected more than a million of these at tlajinga.the fragments, widmer discovers a remarkable similarity in size. looking for explanations, he examined the methods of modern potters. here, within the outskirts of the ancient city, in the neighborhood of san sebastian, a handful of potters still use ancient techniques. man: bueno, este viene siendo de... interpreter: i learned how to do pottery from my grandparents and from my great-grandparents. i watched how they worked. i started when i was very small. keach: oliverio hernandez-resendiz is one of the few remaining potters in san sebastian. he makes large pots that are used primarily for cooking. resendiz works with molds, enabling him to work quickly, while keeping the size and shape of the pots consistent. the use of molds explains why the remains found in tlajinga were so uniform. widmer: it tells us that we're dealing with a specialized production of ceramics -- not simply a whole range of ceramics for use in the compound. but, instead, what we're finding is they're making one o