At the beginning of the Cenozoic, that is, more than 40 million years ago, the first primates appeared. Several branches separated from them, leading to modern apes and humans.
Scientists believe that the extinct human ancestors were arboreal apes – Dryopithecus.
Driopithecus appeared 17-18 million years ago. During this time, their habitats were affected by climate change, which led to the reduction of forests. The Driopithecus had to adapt to life in the open. They laid, apparently, the beginning of the evolution of man, his predecessors – Australopithecus.
Australopithecus (“southern monkeys”) lived in the steppes of Africa about 5-1 million years ago.
They combined the characteristics of humans and apes. The brain had a volume of 440–600 cm³. The height was 120-140 cm.
The main achievement of the Australopithecus was upright posture.
The front limbs – arms were freed. Now they could hold stones, sticks, and other tools.
The Australopithecines, apparently, have not yet processed their tools, but simply used what they found: sticks, stones, bones, horns. They could kill a small animal, drive away a predator.
The later of the Australopithecus were, apparently, the direct ancestors of people.