The Mayo Chinchipe ceramic assemblage found in the upper Amazon of Ecuador and Peru is one of the first pottery manifestations of the Formative period in this part of America (5300/2300 BP). Its stylistic, technological and symbolic characteristics reflect a heterarchic society with a high degree of cohesion, which expanded over a vast territory that included different ecological niches (altitude tropical humid forest to low montane dry forest). The regional interactions that have been witnessed include the Pacific coast, the Andean cordillera (over 3000 m asl) and the low piedmont of western Amazonia (400 m asl). The pottery has thin walled wares, with well-finished surfaces that coexisted with coarser utilitarian wares. In the beginning of the sequence the wares are monochrome, but in time mineral pigments have been used to paint and highlight certain zones in red, cream or white colors. The plastic decoration techniques include incised, excised and printed motived as well as a moderate use of appliques. The forms include open vessels (low and high bowls) and closed vessels (ollas: pots with or without necks, jars and bottles). Outstanding forms are effigy bottles and the fist stirrup-spout vessels of the American continent.