The History of East African Prehistoric Discoveries

In 1893, geologist J.W. Gregory first recognized the contributive importance of East Africa to better understanding the evolutionary history of ancient technologies when he found evidence of "paleoliths" in and around an ancient lake in Maasai country (Cole 1965). In the twentieth century, German entomologist Kattwinkel noted the presence of fossils in 1911 at a rift escarpment known to the Maasai as Olduway, which shortly led German paleontologist Hans Reck to continue work at Olduway (later called olduvai gorge). Reck noticed that important paleontological localities occur where the Side Gorge meets the Main Gorge. But with World War I beginning, his work came to an abrupt halt. When the war came to an end, extensive archeological research resumed across all of Africa, especially in East Africa. Yet the main scientific quest was not to discover more forgotten material cultures; rather, current scientific interests strove to elucidate past climatic events in order to better understand the chronological framework of the fossil and archaeological records that were already known.

This is exactly what prompted E.J. Wayland to survey Uganda while he served as the Director of Geological Survey of Uganda. In 1934, he reported an ancient split-pebble industry based on rolled material taken from the Kafu River in western Uganda, which was later extended to include other Ugandan sites, such as Kagera Valley and Nsongezi, by South African archeologist C. van Riet Lowe. It was the nature of the sedimentary record that led Wayland to describe environmental intervals he called "pluvials," literally meaning rains, that he thought would link Europe's four-glacier concept to Africa. Today, the Kafuan industry is not recognized as a legitimate stone-tool technology because the stone tools (split-pebbles) are the result of natural fractures, most likely caused by the river environment from which they were found, and the pluvial concept is long forgotten. Wayland was also responsible for describing the Sangoan and Magosian Middle Paleolithic industries from type-sites also located near the Kafu River; the Sangoan is still recognized as a legitimate industry, but Magosian tools fall within the range of variation of an Acheulean-Levallois techno-complex.

Prior to the time that the Kafuan industry made its debut, another famous paleoanthropologist and prehistorian, l.s.b. leakey, was working fervently at stone tool sites in Kenya, dinosaur sites in Tanzania (then Tanganyika), and hominid-bearing deposits in South Africa. After getting his field techniques down in Tanzania and describing simple stone tool manufacture and more recent stone tool technologies of Kenya, in 1931 he organized an expedition to Olduvai Gorge with the help of Hans Reck. He quickly recognized the significance of the stone tools found in the layer cake stratigraphy deposits that ranges in date from 1.9 million years ago at the base, to 1.8 million years ago at Bed I, to recent at Bed IV. Before long, Leakey was back at Olduvai, and from 1935 to 1958 he and members of his team had many celebrated accomplishments in terms of collecting fossil mammals and plenty of stone tools, but had discovered no stone tool maker.

That wouldn't come until 1959 when his wife, mary leakey, discovered Zinjanthropus (Australopithecus boisei), a.k.a. the nutcracker man and, as no surprise, Louis's stone tool maker. Over the decades, the meticulous excavations at Olduvai by Mary and Louis Leakey would engender incredible hominid discoveries and significant advances facilitating phylogenetic inferences of which particular hominids generated flaked stone technologies. In general, the Leakey's connubial commitment to research was well received, but it was Mary Leakey's work in particular that would ultimately change the course of human evolutionary studies recording the evidence of an ancient past and of how to interpret human prehistory in East Africa. The simple flake and core industry found at Olduvai Gorge became known as the Oldowan Industrial Complex (see below). In earlier deposits, the Leakeys also came across larger tools and cores that were worked on both sides, hence the name biface. Handaxes, picks, and cleavers are all bifaces and resemble the Acheulean industry from Europe. The size of the tool/core and the amount of bifacial flaking would determine the category of flaked stone technology. Acheulean is found at Olduvai Gorge, but intermediate industries are also recognized.

From 1953 to 1966, j.d. clark, Director of the National Museum of Zambia, excavated an open-air stratified Pleistocene site in Zambia near Tanzania called Kalambo Falls. This site produced Acheulean, Sangoan, and Epipaleolithic industries that are believed to range in age from the Middle Pleistocene to recent. In 1961, Clark became faculty at the University of California at Berkeley. This marked a paramount period in prehistory studies in East Africa. It was during Clark's tenure at Berkeley that many talented students would undertake archeological training in East Africa-they were to influentially dominate the field for the next thirty years. A protégé of Louis Leakey, South African archaeologist Glynn isaac, received his Ph.D. from Cambridge in 1961. He is best known for his work in East Africa, especially at olorgesailie, which is an Early to Late Pleistocene locality in southern Kenya dated to 1.2 to .05 million years ago, and the Koobi Fora field school that he managed alongside Richard Leakey. Various layers at Olorgesailie dated to 780 thousand years ago are inundated with Acheulean handaxes and some skeletons of Theropithecus oswaldi leakeyi, which suggests that hominids may have hunted these now-extinct especially large species of baboons. According to archaeologist Rick Potts of the National Museum of Natural History, Washington, D.C., who has been the principal investigator at Olorgesailie since the unexpected death of Glyn Isaac in the mid-1980s, the site documents an important character suite of Pleistocene large mammals including the last known occurrences of Elephas recki and Hipparion.

Continuing in the Berkeley tradition during the 1970s, J.W.K. Harris, a doctoral student of J.D. Clark and Glyn Isaac, investigated the Karari escarpment located on the eastern border of Lake Turkana and discovered an archaeological site composed of single platform core/scrapers. Because it was different from the Early Oldowan Industry and Developed Oldowan A & B recovered from Beds I, II, and III, Harris named this innovative technological complex the Karari Industry (Harris 1978). Karari sites are typically concentrated within channel gravels and floodplain silts in the lower portion of the Okote member of the Koobi Fora Formation, which is dated to 1.6 million years ago. Harris is also responsible for the discovery of the oldest known stone tools, which were collected in situ in the Kada Hadar Member of the Gona sequence of Hadar, Ethiopia, dated to 2.6 million years ago. The simple flake pebble tool industry at Gona is typically Oldowan. In the late 1980s, Harris also turned his attention to the Western Rift Valley, where he discovered another Late Pliocene-Early Pleistocene open-air site known as Senga-5 in Congo (formerly Zaire) (Harris et al. 1987). Senga-5 has produced numerous small quartz flakes and simple pebble cores. These are difficult to date through sedimentary analytical techniques; biostratigraphy of associated fauna suggests correlation with the Omo sequence of the Eastern Rift Valley, dated to 2.3 to 1.9 million years ago. Harris also concerned himself with tracing the origins of fire technology in the fossil record, with the earliest evidence of fire use by hominids coming from East Africa at 1.4 million years ago at FxJj 50 and Chesowanja, Kenya (Harris 1982). J.W.K. Harris, now at Rutgers University, has many former and current students working in East Africa continuing his legacy.

Source:
The evolution of modern humans in Africa: a comprehensive guide
By Pamela R. Willoughby
Page No. 57,58,59,60
(http://books.google.com)