Found back in 1924 in South Africa, Australopithecines have already passed the main milestone on the path of their evolution about 5 million years ago: they moved more or less freely on their feet. True, Australopithecines were not our direct ancestors. Now there are several species of Australopithecus, of which the most progressive is the socalled Zinjanthropus, who lived a million and a half years ago on the territory of modern Tanzania (East Africa). And there, in 1960, the first skull of a creature that lived 250-300 thousand years before the zinjanthropus was found and therefore called the prezinjanthropus. This creature, according to most scientists, was already a man!
The Oldowai Gorge is located in Northern Tanzania. A thick layer of sediments with layers of volcanic ash and tuff is extremely convenient for dating. More than forty years ago, a young scientist Louis Leakey arrived here in search of traces of primitive man. He and his wife Mary that's the whole expedition. Leakey was sure that the lake, which once occupied the site of the current Oldovai Gorge, should have attracted animals, and therefore people who hunted them. And indeed, soon he began to find the remains of hunting camps with bones of animals and Australopithecines (which were also hunted).
But the most interesting discovery was waiting for the scientist in the lower layers of the gorge. This is a 1960 discovery, a prezinjanthrope. A small bipedal creature with a height of 122-140 centimeters, at least thirty centimeters lower than a pithecanthropus, and with a brain volume one and a half times smaller, but with a hand closer in structure to a human than that of pithecanthropus and Javanese and Peking. The scientific world did not immediately recognize this creature's right to be called a man.
The ability to create tools distinguishes even the most primitive human collective from a herd of monkeys. To prove that a prezinjanthrope had tools, Leakey understood, means to prove irrefutably: a prezinjanthrope is a human being. And Leakey found them. Hundreds of stone tools piled in heaps resembling heaps of pebbles. Stones similar to sea pebbles, slightly processed along the edge, turned into universal scraping and cutting tools. Scientists, finding more and more "pebble piles", were convinced that the blows inflicted on each of these stones were systematic. So, after all, they were created by man, not nature!
The discoveries gave impetus to the organization of searches north of Tanzania in Kenya and Ethiopia. In southwestern Ethiopia, Oldowai stone tools from 1.9 million to 2.2 million years old were discovered, and in Kenya in 1970, the same Oldowai tools and broken bones of animals about 2.6 million years old were discovered. Two years later, in northern Kenya, Louis Leakey's son Richard found the skull and femur bones of the oldest known ancient people at that time. His skull resembled that of a modern man. His supraorbital ridges were not strongly pronounced and his jaw was less heavy and massive than that of a pithecanthropus. This man lived 5-5.5 million years ago.