The emergence of the Middle Stone Age (MSA) in North Africa has been traditionally considered the result of H. sapiens dispersals triggered by late Middle Pleistocene ecosystem fragmentation from areas of endemism in East Africa, where early H. sapiens fossils dated to ca. 200 ka 1 have been found; Sangoan and Lupemban technocomplexes would have represented the archaeological signature for these first expansions 2 . This framework has been questioned in light of African Multiregionalism concepts building upon a series of independent data 3 , including the dating of MSA assemblages associated to H. sapiens fossils to ca. 315 ka at Jebel Irhoud 4,5 , as well as attempts for a more regional interpretation of technological sequences and variation 6,7 .

Late Middle Pleistocene human biogeography of North Africa is directly linked to the Sahara, which has long been identified as a driver for biological diversification and population separation 8,9 . However, while being recognized as a critical area for human evolution, our current understanding of the Saharan biogeographic role remains speculative because its archaeological, geochronological, and paleoanthropological data are too scarce and poorly distributed to resolve the relationships between its northern and southern regions at this critical time period.

Here, we report results from investigations at Wadi Lazalim in southern Tunisia, at the northern edge of the Sahara. The area preserves an open-air sedimentary sequence of mostly late Middle Pleistocene age-dating from at least Marine Isotopic Stage (MIS) 8 to the transition from the MIS6 to MIS5 interglacial. The archaeological evidence from lithic assemblages in sub-primary deposition comprises well-recognizable technological elements for which infrared luminescence data provide some chronometric insight revealing fresh information on early MSA human occupation of the northern Sahara and contributing new elements for the discussion about the spread of MSA techno-complexes from sub-Saharan Africa into North Africa in the late Middle Pleistocene.