Ardipithecus ramidus

Ardipithecus ramidus is an early hominin species that lived about 4.4 million years ago. It is considered an important link in human evolution, showing characteristics of both early apes and later human ancestors. Discovered in Ethiopia, Ardipithecus had a mix of traits: it walked upright on two legs but also had features suited for movement in trees. Its anatomy suggests that early humans gradually transitioned from tree-dwelling to walking on the ground, providing insight into how our ancestors adapted for upright walking while still retaining some arboreal abilities.