The Laetoli Footprints

The Laetoli Beds are located not far from the famous Serengeti National Park. During one of its eruptions a nearby volcano, Sadiman, threw ash out into the air, and rain converted this to mud in which the tracks of many animals were recorded and fossilized. Among these animals were the hominids. There are two parallel tracks of two individuals, one of them walking in the tracks of the other. The individual on the left is very small, perhaps a female or a child.

The characteristics of these Laetoli footprints are incredibly modern. They show no sign of insecure or "imperfect" bipedalism; rather they indicate, even in the smallest details, a way of walking identical to our own. The foot of a chimpanzee, gorilla, or orangutan is very different from a human foot. In fact it is more like our hand - flat, with a big toe which is shorter than the others and can separate from them laterally, and extends away from the other toes on each step.

In the Laetoli footprints we can study the mode of walking of the hominids which produced them. If you are fortunate enough to have a beach nearby, you can compare these fossil footprints with your own, and appreciate their extraordinary similarity. In each step taken by the Laetoli hominids the front foot was supported first on the heel, leaving a deep impression in the soft ground. Part of the body weight was then trans­ferred through the arch or instep. After this, the foot flexed over the toes, giving a final impulse to lift the foot from the ground and extend the leg forward. As in modern humans, the big toe was fundamental to this final phase (being the last to leave the ground), and it therefore pointed forward like the other toes and was aligned with them. Fossils of Australopithecus afarensis of the same age as the footprints have been found in the Laetoli Beds.

Questionnaire:

• What are Laetoli footprints? Explain.