This review revealed the size and morphological changes of soybean (Glycine max) seeds in the Jomon period by compiling and comparing their impressions detected by the replication method. This review confirmed that soybean seeds that first appeared in the middle phase of the initial Jomon period, the latter half of the 8th millennium BC, in central Japan become larger through later Jomon periods. Soybean seeds of cultivated types came to be distinguished by the middle Jomon period, the latter half of the 4th millennium BC. This enlargement in seed size is one of the characteristics accompanying plant domestication. Four mophological types can be recognized in the soybean seeds of the Jomon period, and this indicates possibile differentiation of soybean breeds during the Jomon period through the use of wild soybeans to that of domesticated ones.

View full abstract

Impressions of slender grains similar to those of wild Setaria species are often concomitant with foxtail millet impressions on pottery from the Neolithic to Bronze Age sites in Japan, Korea, and China. They have been identified as grains of weed species in millet fields that were mixed with harvested crop grains. However, results of threshing experiments showed that the slender floret of the wild Setaria type was a variation with unripe caryopses in cultivated foxtail millet grains and was included in the threshed and winnowed products of the experiments. Based on the morphological comparison with modern wild millets, most impressions of the slender type grains were identified as the cultivated foxtail millet. The characteristics and occurrence of grains in threshed and winnowed products including caryopses indicate that impression assemblages of foxtail millet grains originated from threshed products.

View full abstract

Urushi-lacquered combs are among the most important artifacts characterizing the urushi lacquer culture of the Jomon period in Japan. We conducted radiocarbon dating of two lacquered combs of the Jomon period, one excavated from the Mibiki site of the late phase of the initial Jomon period and another excavated from the Torihama shell midden of the early Jomon period. Their dates were 6290 ± 30 14C BP (ca. 7200 cal BP) and 5310 ± 30 14C BP (ca. 6100 cal BP), respectively. These results show the comb from the Mibiki site to be one of the oldest remains of urushi-lacquered artifacts of the Jomon period and that from the Torihama shell midden to be of the late phase of the early Jomon period.

View full abstract