page_title: Laetoli
section_title: History of research
hierarchical_section_title: Laetoli / Background / History of research
caption_attribution_description: English: Cast of the "Laetoli footprints" -- the earliest known human footprints in the world, on display in the Hall of Human Origins in the Smithsonian Museum of Natural History in Washington, D.C. These footprints are those of Australopithecus afarensis. The entire footprint trail is 88 feet long and includes impressions left by two individuals. They were made 3.6 million years ago in Laetoli, Tanzania, when A. afarensis walked through wet volcanic ash. Paleontologist Mary Leakey found them in 1976, but they were not identified until Paul Abell did so in 1978. There are 70 footprints in total.
context_page_description: Laetoli is a site in Tanzania, dated to the Plio-Pleistocene and famous for its hominin footprints, preserved in volcanic ash. The site of the Laetoli footprints is located 45 km south of Olduvai gorge. The location and tracks were discovered by archaeologist Mary Leakey and her team in 1976, and were excavated by 1978. Based on analysis of the footfall impressions "The Laetoli Footprints" provided convincing evidence for the theory of bipedalism in Pliocene hominins 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 hominin finds, as well as a comprehensive reconstruction of the paleoecology.
  Dated to 3.7 million years ago, they were the oldest known evidence of hominin bipedalism at that time. Subsequently, older Ardipithecus ramidus fossils were found with features that suggest bipedalism. With the footprints there were other discoveries excavated at Laetoli including hominin and animal skeletal remains.
context_section_description: Laetoli was first recognized by western science in 1935 through a man named Sanimu, who convinced archeologist Louis Leakey to investigate the area. Several mammalian fossils were collected with a left lower canine tooth originally identified as that of a non-human primate, but later was revealed (in 1979, by P. Andrews and T. White) as the site's first fossil hominin.
  In 1938 and 1939, German archaeologist Ludwig Kohl-Larsen studied the site extensively. Several hominin remains, including premolars, molars, and incisors, were identified. A later excavation in 1959 revealed no new hominins, and Laetoli went relatively unexplored until 1974—when the discovery of a hominin premolar by George Dove revived interest in the site. Mary Leakey returned and almost immediately discovered the well-preserved remains of hominins. In 1978, Leakey's 1976 discovery of hominin tracks—"The Laetoli Footprints"—provided convincing evidence of bipedalism in Pliocene hominins and gained significant recognition by both scientists and laymen.
caption: Cast of the Laetoli footprints, on display in the Hall of Human Origins in the Smithsonian Institution's National Museum of Natural History in Washington, D.C.
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