Answer
The Laetoli footprints, discovered by Mary Leakey in Tanzania in 1978, are a set of fossilized hominin footprints preserved in volcanic ash. These footprints, dating back 3.6 million years, provide evidence of bipedalism, or walking upright, in early hominins. The footprints show a clear impression of the feet, toes, and heels, and they suggest that the individuals who made them were walking in a group.