Based on analysis of the footfall impressions "The Laetoli Footprints" provided convincing evidence for the theory of bipedalism in Pliocene Hominina and received significant recognition by scientists and the public.

Since 1998, paleontological expeditions have continued under the leadership of Amandus Kwekason of the National Museum of Tanzania and Terry Harrison of New York University, leading to the recovery of more than a dozen new Hominina finds,[2] as well as a comprehensive reconstruction of the paleoecology.

Laetoli was first recognized by western science in 1935 through a man named Sanimu, who convinced archeologist Louis Leakey to investigate the area.

Although much debated,[citation needed] researchers have tentatively concluded that Australopithecus afarensis is the species of the three hominins who made the footprints at Laetoli.

This conclusion is based on the reconstruction of the foot skeleton of a female A. afarensis hominin by anthropologists Tim D. White and Gen Suwa of the University of California, as well as detailed footprint analysis by Russel Tuttle of the University of Chicago; he compared human and other bipedal animals such as bears and primates, including gaits and foot structure, and taking into account the use of footwear.

A. afarensis is an obligate bipedal hominin with the beginnings of sexual dimorphism attributed to its species, and brain size very similar to that of modern chimpanzees and gorillas.

Analysis of the Laetoli footprints indicated the characteristics of obligate bipedalism: pronounced heel strike from deep impressions, lateral transmission of force from the heel to the base of the lateral metatarsal, a well-developed medial longitudinal arch, adducted big toe, and a deep impression for the big toe commensurate with toe-off.

The principal discovery, made by Mary Leakey and her team in 1976 (and fully excavated by 1978), is a 75-foot (24-meter) line of Hominina fossil footprints, preserved in powdery volcanic ash originally thought to have been from an eruption of the nearby (20 km) Sadiman volcano.

While walking back to camp one evening, Hill fell trying to avoid a large ball of elephant dung thrown at him by a colleague.

As the tracks lead in the same direction, they might have been produced by a group visiting a waterhole together, but there is nothing—or very little (see below, Interpretation and significance)—to support the common assumption of a nuclear family.

The feet do not have the mobile big toe of apes; instead, they have an arch (the bending of the sole of the foot) typical of modern humans.

Further analysis indicated that individual S1 was considerably larger than any of the three individuals from site G. Other prints show the presence of twenty different animal species besides the hominin A. afarensis, among them hyenas, wild cats (Machairodus), baboons, wild boars, giraffes, gazelles, rhinos, several kinds of antelope, Hipparion, buffaloes, elephant relatives (of the extinct genus Deinotherium), hares and birds.

Some analysts have noted in their interpretations that the smaller trail bears "telltale signs that suggest whoever left the prints was burdened on one side.

The footprint impression has been interpreted as the same as the modern human stride, with the heel striking first and then a weight transfer to the ball of the foot before pushing off the toes.

[14] Climate changes that caused a shift from forest to grassland environments have a strong correlation with upright posture and bipedalism in hominins.

A team of specialists, one being Fiona Marshall, re-excavated half of the trackway to record its condition, stabilize the surface, extract dead roots and rebury it with synthetic geotextile materials.

[13] Proposals for lifting the track and moving it to an enclosed site have been suggested, but the cost is viewed as outweighing the benefits: the process would require much research, a large amount of money, and there is a risk of loss or damage.