MicroCT visualisations of organic inclusions within pottery sherds from Khashm el Girba 23 (KG23), Sudan, reveal domesticated sorghum (Sorghum bicolor subsp. bicolor) at c. 3700–2900 BCE. The percentage of non-shattering spikelet bases was c. 73% of identifiable visualizations, with c. 27% representing wild types. These analyses demonstrate the domestication of sorghum is significantly earlier than suggested by previous archaeological research. These results also demonstrate that microCT scanning is a major qualitative and quantitative advance on pre-existing methods for the investigation of crop remains in pottery sherds, which hitherto have been reliant on surface impressions; it is non-destructive, provides higher resolution 3D imaging of organic inclusions, and enables greater archaeobotanical recovery of inclusions within a sherd. MicroCT analysis of ceramics, mudbrick and other building materials has considerable potential for improving the chronologies and resolution for the domestication of other cereals in the past.

Four decades have passed since Harlan and Stemler (1976) proposed the eastern Sahelian zone as the most likely center of Sorghum bicolor domestication. Recently, new data on seed impressions on Butana Group pottery, from the fourth millennium BC in the southern Atbai region of the far eastern Sahelian Belt in Africa, show evidence for cultivation activities of sorghum displaying some domestication traits. Pennisetum glaucum may have been undergoing domestication shortly thereafter in the western Sahel, as finds of fully domesticated pearl millet are present in southeastern Mali by the second half of the third millennium BC, and present in eastern Sudan by the early second millennium BC. The dispersal of the latter to India took less than 1000 years according to present data. Here, we review the middle Holocene Sudanese archaeological data for the first time, to situate the origins and spread of these two native summer rainfall cereals in what is proposed to be their eastern Sahelian Sudan gateway to the Red Sea and the Indian Ocean trade.

Since the 1970s, the quest for finding the origins of domesticated sorghum in Africa has remained elusive despite the fact that sorghum (Sorghum bicolor (L.) Moench. sensu stricto) is one of the world's most important cereals. Recognized as originating from wild populations in Africa (Sorghum arundinaceum (Desv.) Stapf), however, the date and cultural context of its domestication has been controversial, with many scholars inferring an early Holocene origin in parallel with better-known cereal domestications. This paper presents firm evidence that the process of domesticating sorghum was present in the far eastern Sahel in the southern Atbai at an archaeological site associated with the Butana Group. Ceramic sherds recovered from excavations undertaken by the Southern Methodist University Butana Project during the 1980s from the largest Butana Group site, KG23, near Kassala, eastern Sudan, were analyzed, and examination of the plant impressions in the pottery revealed diagnostic chaff in which both domesticated and wild sorghum types were identified, thus providing archaeobotanical evidence for the beginnings of cultivation and emergence of domesticated characteristics within sorghum during the fourth millennium BC in eastern Sudan.