This is a quartzite Lupemban bifacial tool (24 cm long), found in the Southern Niger region.
The Lupemban is an early MSA industry in Central Africa and on the fringes of the Congo basin first described by Breuil more than 60 years ago. This technocomplex is characterized by the presence of bifacial lanceolate points, core-axes and backed blades. Unfortunately sites with contextual information are still rare. JD Clark suggested the heavy duty tool component points to wood-working, based on the association of the Kalambo Falls site in Zambia with deciduous woodland, and preserved wood at site. However, a number of other sites, such as those excavated by in Kenya (Lake Victoria Basin) were clearly occupied open grassland or savanna areas.
At Kalambo Falls the MSA Lupemban assemblages are intercalated between a late Acheulean, followed by a Sangoan and later strata with LSA material.
The Acheulean to Middle Stone Age transition at this key site occured within a broad time interval of 500–300 k.a. according to recent published Optically stimulated luminescence dates. In addition the radiometric dates for the Lupemban at Twin Rivers (Zambia) indicate OIS 7 or 6 ages. At site 8-B-11 at Sai Island, Sudan, the Lupemban also follows an Acheulean and Sangoan and is dated to the OIS6. Similar findings from Nubia are known from Arkin 5 and Khor Abu Anga.
It is actually suggested that the Lupemban may represent the initial dispersal of Homo sapiens into the equatorial forest belt, evolving to an insufficiently dated Lupembo-Tshitolian during the Later Pleistocene and another dispersal event into the upper Nile divide, where it is later replaced by the MSA / Nubian-complex.
Please read a very interesting paper about “style” and “symbols” during the MSA: