The Australopithecus afarensis species is said to be 3.9 million year old and we are typically from Africa in areas near Ethiopia. An amazing discovery of a 40% complete skeleton of an adult female, named Lucy, lead to the claim that the Australopithecus afarensis was the first ancestor to all hominins. With her mixed traits, her fossil remains helped define the ideas about our early ancestors. Lucy was about 3.5 feet tall, the size of a chimpanzee and had long arms, a small cranium, and a jaw that matched those of early apes. However, she also exhibited humanlike qualities. Later 13 more body remains of Australopithecus afarensis were found and are now known as the First Family. Which came to the study that all primates of my kind were bipedal, sexually dimorphic, had the similar joints and facial features to humans. Thus, Australopithecus afarensis revealed a remarkable species that had both humanlike and apelike features. .
Fossil tracks found in the Laetoli beds confirmed that the Australopithecus afarensis were in fact bipedal. Although the exact reason why our primates' species adapted from being quadrupeds is not yet known, this is the closet link we have in comparison with the only two legged walking Homo sapiens. It is crucial to look at the similarities between the knee joints of a modern human compared to us. We both have a bicondylar angle that is typical for today's human bipeds that serves to place the leg under the body's center to support when walking (Stern 1983:279). This enabled early anthropoids to stand for longer periods of time and walk long distances than relying on using all four limbs. Because of this new trait, our pelvis was forced to change as well in order to facilitate being able to keep balance. This change limbs also allowed the pelvis inlet to reshape itself the side-to-side that reflects the shape needed for bipedal locomotion (Clark 2014:355). Other traits of bipedalism included the flexors in our wrist that allow helpful movements in arboreal settings (Stern 1983:282).