Final answer:
The Australopithecus afarensis had long, curved fingers and arms, suggesting both arboreal and bipedal locomotion. They lived in East Africa around 3.9 to 2.9 million years ago in regions that offered both savannah and wooded environments.
Step-by-step explanation:
The finger shape of Australopithecus afarensis, an early hominin species, was long and curved. This physical characteristic, along with their long arms, suggests that they spent time hanging from branches and potentially led a partly arboreal lifestyle. However, the shape of their pelvis resembled that of modern humans, indicating they were also capable of bipedal locomotion. The pelvis of A. afarensis was shorter and wider than that of great apes, supporting this theory. Paleoanthropologists believe these morphological features indicate a form of locomotion in A. afarensis that was a mix between climbing and bipedal walking. This species is best known through the fossil specimen famously dubbed "Lucy," discovered in the Afar region of Ethiopia.
Regarding their habitat, fossil evidence of A. afarensis was primarily found in East Africa, across Ethiopia, Kenya, and Tanzania. The presence of their fossils in these regions, along with the environmental data from the period they lived in, suggests they inhabited savannah-like environments with some wooded areas. This aligns with their anatomical features that indicate both ground-dwelling and climbing abilities. Their fossils date back between 3.9 and 2.9 million years ago, with evidence pointing to a trend in the evolution of smaller teeth and jaws compared to those of apes.