Early man Skeletal remains in West Africa have not so far produced remains of early forms of men or hominids, such as those found in eastern and southern Africa, nor artefacts of correspondingly early dates. Can it be assumed that there were such beings in West Africa? Is our present lack of data due to the fact that these hominids were not living at the time in West Africa, or is it simply because the evidence has not yet been found?
This is a question that is impossible to answer at present but no research effort comparable to that in East Africa has yet been made in West Africa. It also has to be admitted that deposits of the right age appear to be scarcer in West Africa, and it is notorious that in the prevailing conditions of high humidity and soil acidity, preservation conditions are very much worse.
This fact is illustrated by data of a much later age: a distribution m a p of Africa plotting finds of skeletal remains of the Late Stone Age shows a complete blank in the Zaire-West Africa area. Yet since the compilation of that map, dated finds have been made in Nigeria and Ghana, which show that the blank was indicative of a state of research, not of an absence of human occupation.
The same may then be true for the earlier period we are now considering, and it may also be true of a distribution map of the found places of vertebrate fossils of the Lower and Middle Pleistocene ages, which shows a similar blank. As far as one can see, there must have been ecological conditions in certain parts of West Africa very similar to those which supported the Australopithecines of East Africa, but of course, this does not mean that these areas in fact were occupied.
There are many areas of tropical rainforest that could support gorillas today, but in fact they are only found in two circumscribed areas; and in spite of some similarity of conditions, the West African savannah does not support the same collection of game types as East Africa, nor in the same density.
The cranio-facial section of a skull discovered 200 kilometers west-south-west of Largeau provides one positive piece of evidence for the theory that early hominids lived in suitable areas of West Africa early in the Pleistocene. It was named Tchadanthropus uxoris, and was first thought to be an Australopithecine but was later regarded as more akin to Homo habilis. The uncertainties in this case stem from the lack of secure dating and from the fact that the skull is only fragmentary.
Further investigation of the skull, with its blend of archaic and advanced traits, has revealed that it clearly evolved towards Homo erectus, a more advanced stage of hominids, with cranial capacities ranging from 850 to 1300 cc. Once again, there are no examples of this form from West Africa, although specimens of this type, called Atlanthropus mauritaniens, have been found in Algeria.
Artifacts: Although prehistoric man made tools of bone and wood as well as of stone, wood is rarely preserved, because the soil conditions in West Africa militate against the survival of bone.
Apart from utilized and roughly trimmed flakes, the earliest and simplest types of stone tools consist of pebbles or lumps flaked by percussion to form crude chopping and cutting tools with edges anything from 3 to 12 centimeters long; they are known as Oldowan-type tools, after Olduvai Gorge in Tanzania. Such tools are found in many places in Africa, and the early m e n who made them may well have spread over most of the savannah bushy grasslands of Africa.
Examples of such tools are known from a number of places in West Africa, but it is not at the moment possible to be sure if any of them genuinely date from the same period as the Oldowan industry of East Africa, which may be put in the period between 2 and 7 million years ago.
A careful investigation of pebble tools found along the Gambia River in Senegal demonstrated that some were likely to be of Neolithic origin and others to have derived possibly from the late stone age; there was no stratigraphically evidence for an industry of pre-Acheulian age.
So we can only be certain that pebble tools date from an early era if they are independently dated by being discovered in situ in deposits that can be dated, either relative or absolute. Although paleontology gives some relative dating for the Yayo deposits that produced Tchadanthropus, unfortunately, there were no associated implements.
From the evidence of fossil bones of the extinct Hippopotamus imaguncula, which came from a depth of 58 meters in a well in Bornu,. Furthermore, it is possible that deposits of the Chad Basin contain paleontological material of the Pleistocene age—and, as likely as not, archaeological material as well—but they lie under a mantle of later drift of great thickness.