Toumai (Sahelanthropus tchadensis) was thought to be right at the foot of the human family tree.

BBC: NEWS | Science/Nature | Evolution's human and chimp twist

And a seven-million-year-old hominid from Chad, known as Sahelanthropus tchadensis and nicknamed Toumai, may also have been bipedal.

BBC: NEWS | Science/Nature | Scientists unearth early skeleton