Which African site preserves 3.2-million-year-old 'Lucy'?

The Afar region of Ethiopia, where Donald Johanson's team found about 40 per cent of a single Australopithecus afarensis skeleton in 1974 - an extraordinary proportion for a hominin fossil, which usually means fragments of jaw.

She settled an argument about sequence. The pelvis and knee show she walked upright, and her brain was small - so bipedalism came first and the big brain much later, rather than the other way round, which had been the assumption. Ethiopians call her Dinkinesh, meaning you are marvellous; the English name comes from the Beatles song playing in camp the night she was found.

The fossil record has moved on around her without displacing her. Ardipithecus at 4.4 million years, Sahelanthropus at closer to seven, and Australopithecus sediba have all complicated the story, and the Laetoli footprints - preserved in volcanic ash at 3.6 million years - show the walking directly rather than by inference. Lucy remains the reference point partly because of how complete she is and partly because the public has a name and a face, which the others do not.