Laetoli fossil footprints. Artwork showing the Laetoli footprints that were preserved in volcanic ash deposits around 3.5 million years ago. They were discovered in 1976 in Laetoli, Tanzania. As there were no knuckle impressions, this is evidence that these hominins, thought to be Australopithecus afarensis, walked upright. The ash was from an eruption of the Sadiman volcano.
