The first species that is believed to have walked upright is Australopithecines.
Australopithecines are an extinct genus of hominid primates. Species of this genus have lived in Africa for just over 3.9 million years until about 2 million years ago. The greatest novelty contributed by australopithecines is that they moved in a bipedal manner. The size of their brain was similar to that of the current great apes. They lived in the tropical zones of Africa, feeding on fruits and leaves. There is a consensus that australopithecines played an essential role in human evolution, being one of the species of this genus that gave rise to the Homo genus in Africa about 2 million years ago.