14 dating 23
Although other early rice remains in the form of phytoliths were found in a marine sediment core from the Okinawa Trough and dated to the Bølling-Allerød warm period (13,900–13,000 cal yr B.P.) (9), the nature of the rice remains as to their wild or domesticated status is unclear because of a limited application of available rice identification criteria.
Thus, the measured C values of the phytoliths are shown with a high level of confidence to be from the phytolith samples themselves.Accordingly, further dating initiatives are needed to constrain the absolute-calendar time of the rice remains.Radiocarbon dating of phytoliths, microscopic bodies of silica formed in plant cells, is an established technique that can be traced back to the 1960s (15).However, because of the poor preservation of macroplant fossils, many radiocarbon dates were derived from undifferentiated organic materials in pottery sherds.These materials remain a source of debate because of potential contamination by old carbon.Direct dating of the rice remains might serve to clarify their age.
Here, we first validate the reliability of phytolith dating in the study region through a comparison with dates obtained from other material from the same layer or context.
The results indicate that rice domestication may have begun at Shangshan in the Lower Yangtze during the beginning of the Holocene.
L.) recovered from the Shangshan site in the Lower Yangtze of China have previously been recognized as the earliest examples of rice cultivation.
Our phytolith data indicate that rice remains retrieved from early stages of the Shangshan and Hehuashan sites have ages of approximately 9,400 and 9,000 calibrated years before the present, respectively.
The morphology of rice bulliform phytoliths indicates they are closer to modern domesticated species than to wild species, suggesting that rice domestication may have begun at Shangshan during the beginning of the Holocene.
Carbon dating has given archeologists a more accurate method by which they can determine the age of ancient artifacts.