Early Pleistocene refers to the period from Pre-Günz to either the end of Mindel or the end of Günz glaciation, the latter being rather widely adopted in the field of geology and palaeontology. The most important man-like creatures so far known from the period are Australopithecines which accompany with the Villafranchian fauna in Africa. According to the finds at their living sites, it seems out of question that they had already acquired the bipedal locomotion and reached the level of tool-making.
In 1931 Dr. N. Naora discovered a human coxal bone imbedded in an earth lump which he believed to have been dislocated down from the upper Lower or lower Middle Pleistocene deposit at a cliff on the coast of the Inland Sea near Akashi, Hyogo Prefecture. The bone was destroyed by fire in 1945, but a few years later its cast was studied by Dr. K. Hasebe, who found primitive characteristics of the bone and proposed a tentative name Nipponanthropus akashiensis. Besides the bone, Dr. Naora discovered crude stone implements from the layer comparable to that of Nipponanthropus. However, it remains controversial as yet whether the Pleistocene deposit had actually yielded the bone in question.
