<P> Olduvai Gorge, or Oldupai Gorge, in Tanzania is one of the most important paleoanthropological sites in the world; it has proven invaluable in furthering understanding of early human evolution . A steep - sided ravine in the Great Rift Valley that stretches across East Africa, it is about 48 km (30 mi) long, and is located in the eastern Serengeti Plains in the Arusha Region not far, about 45 kilometres (28 miles), from Laetoli, another important archaeological site of early human occupation . The British / Kenyan paleoanthropologist - archeologist team Mary and Louis Leakey established and developed the excavation and research programs at Olduvai Gorge which achieved great advances of human knowledge and world - renowned status . </P> <P> Homo habilis, probably the first early human species, occupied Olduvai Gorge approximately 1.9 million years ago (mya); then came a contemporary australopithecine, Paranthropus boisei, 1.8 mya, then Homo erectus, 1.2 mya . Homo sapiens is dated to have occupied the site 17,000 years ago . </P> <P> The site is significant in showing the increasing developmental and social complexities in the earliest humans, or hominins, largely as revealed in the production and use of stone tools . And prior to tools, the evidence of scavenging and hunting--highlighted by the presence of gnaw marks that predate cut marks--and of the ratio of meat versus plant material in the early hominin diet . The collecting of tools and animal remains in a central area is evidence of developing social interaction and communal activity . All these factors indicate increase in cognitive capacities at the beginning of the period of hominids transitioning to hominin--that is, to human--form and behavior . </P> <P> German neurologist Wilhelm Kattwinkel traveled to Olduvai Gorge in 1911, where he observed many fossil bones of an extinct three - toed horse . Inspired by Kattwinkel's discovery, German geologist Hans Reck led a team to Olduvai in 1913 . There, he found hominin remains, but the start of World War I halted his research . In 1929, Louis Leakey visited Reck and viewed the Olduvai fossils; he became convinced that Olduvai Gorge held critical information on human origins, and he proceeded to mount an expedition there . </P>

Which fossil find was located in olduvai gorge in tanzania