Ardipithecus ramidus is a species of extinct hominin that lived approximately 4.4 million years ago in what is now Ethiopia. It is considered one of the earliest known ancestors of modern humans.
Ardipithecus ramidus was discovered in 1992 by paleoanthropologist Tim White and his team in the Afar region of Ethiopia. The first fossil was a partial skeleton, nicknamed "Ardi", and subsequent excavations have revealed more than 100 specimens.
Ardipithecus ramidus is significant because it provides important insights into the evolution of bipedalism and other characteristics of early hominins. It also challenges the previously held belief that chimpanzees were the closest living relatives of humans.
Ardipithecus ramidus had a combination of ape-like and human-like features. It had a small brain (about the size of a modern chimpanzee), but also had adaptations for walking upright on two legs. Other notable features include long arms, opposable big toes, and a reduced canine tooth size.
While there is still much to learn about the behavior of Ardipithecus ramidus, scientists have been able to make some inferences based on its anatomy and the environment in which it lived. For example, its hand and foot bones suggest it was adapted for both climbing and walking on two legs. Its diet likely consisted of a mix of fruits, nuts, and other plant materials, as well as some meat. Evidence also suggests that it lived in wooded areas and may have used tools.