Tree climbing arms and hands, land walking legs and feet, clearly ... a species intermediate between arboreal and terrestrial.
And the more we find out about the habitat of Australopithecus afarensis and earlier hominids the more we find bipedal adaptation linked to life along the boundaries between forest and open areas -- places with lots of opportunities. This also places a pre-adapted bipedal ape with means and motive (heh)
The trees were Eden.
Drinking when we are not thirsty and making love at any time, madam, is all that distinguishes us from the other animals.