Final answer:
Ardipithecus kadabba lived between 5.6 and 5.8 million years ago and is one of the oldest known human ancestors. It was a bipedal species, although its exact place in the human evolutionary tree is still uncertain.
Step-by-step explanation:
Ardipithecus kadabba, a species of early hominid, lived between 5.6 and 5.8 million years ago. It is one of the oldest known human ancestors and is believed to have been bipedal, although uncertainties remain about its exact place in the human evolutionary tree. Ardipithecus kadabba was discovered in the 1990s and provides valuable insights into the early stages of human evolution.