Early domesticated yam (Dioscorea sp.) management in West Africa: evidence from Tse Dura, Middle Benue Valley, Nigeria 11th century AD

Yams represent a nutritionally vital and culturally significant tuber crop across Africa, Southeast Asia, and the Americas. However, due to their poor preservation in archaeological contexts, the recovery and secure identification of yam remains has posed a persistent global challenge. While starch grain and phytolith analyses have shown promise, considerable morphological variability complicates their taxonomic resolution. Recent examination of charred starchy plant parenchyma fragments has revealed unique reproductive features that are distinct in both cell morphology and reproductive phase that are diagnostic of yams ( Dioscorea sp.). The recognition of these diagnostic traits constitutes a methodological advancement in archaeobotanical research. Drawing on this new criterion, we present the first directly dated archaeobotanical evidence for the management of yams ( Dioscorea sp.) as a food resource at the Tse Dura rock shelter (locally known as Indyer Mbakuv) in the Middle Benue Valley, central Nigeria, dating to at least cal. CE 1031–1161 (933 ± 29 BP). The intermittent occupations at this site during the Later Stone Age-Iron Age (LSA-IA) and to the Present have been directly dated using botanical remains. This new evidence supports the inference that yam ( Dioscorea sp.), most likely Dioscorea rotundata , was actively managed by the inhabitants of Tse Dura rock shelter about a thousand years ago, a period coinciding with significant population movements into the Middle Benue Valley.