Middle and Later Stone Age Technology from the Lake Rukwa Rift, Southwestern Tanzania

Anatomically modern Homo sapiens developed in Africa during the Middle Stone Age (MSA)/Middle Palaeolithic; ultimately, their descendants migrated out of Africa and replaced archaic hominids in Eurasia. Their arrival in Europe 30 000 to 40 000 years ago is associated with a major technological shift, from the Middle to the Upper Palaeolithic. In sub-Saharan Africa, MSA people, already biologically modern, appear to have changed their technology around the same time. This new Later Stone Age (LSA) is characterized by microlithic technology. African Stone Age archaeologists are split between those who feel that the LSA marks the beginning of behavioural modernity, and those who feel that some MSA sites, especially the South African ones have similar innovations. The absence of MSA to LSA transitional sites in much of the continent makes it difficult to test these ideas. This paper reports on the analysis of the lithic technology at several MSA and LSA sites from the Rukwa Rift Valley of southwestern Tanzania. There are notable differences between the two, but also signs of continuity in some features. Test excavations at a deep LSA site, IdIu22, show signs of directional change within the LSA occupation, but at no point is there a sudden replacement of one kind of technological system by another.