Maize starch granules (n=4) were recovered from charred organic residues on the inner surface of a ceramic sherd (FS884, Sample 11C). The date was taken from associated charcoal recovered from the same layer and context (Zarrillo et al. 2008:5008).
Zarrillo, S., D. M. Pearsall, J. S. Raymond, M. A. Tisdale and D. J. Quon 2008 Directly dated starch residues document early formative maize (Zea mays L.) in tropical Ecuador. Proceedings of the National Academy of Sciences, USA 105(13):5006–5011.