AGE:
3.6 million years

SIZE:
1.5 meters long

Discovered in 1974-1975 by Mary Leakey the trail consists of two or three fossilized footprints of  bipedal hominids. Their size and stride length indicate that they were about 140 cm (4'8") and 120 cm (4'0") tall. Many scientists claim that the footprints are effectively identical to those of modern humans, while others claim the big toes diverged slightly like apes.