prehistoric Sub-Saharan African periodsSub-Saharan African Earlier Stone Age periodsSub-Saharan African First Intermediate Stone Age periodsSub-Saharan African Middle Stone Age periodsSub-Saharan African Second Intermediate Stone Age periodsSub-Saharan African Later Stone Age periodsprehistoric Africanperiod, prehistoric Sub-Saharan Africanperiods, prehistoric Sub-Saharan Africanprehistoric Sub-Saharan African period