Reconstruction
In 1978 a team working at Laetoli in northern Tanzania uncovered a trail of hominin footprints preserved in volcanic ash and dated to 3.66 million years ago. The Site G trackway runs for some 27 metres and holds around seventy prints, and it remains the oldest unequivocal evidence of committed upright walking in the human lineage. The prints are not food remains, and nothing at the site records a meal. Their relevance to food history is mechanical: they show how these hominins moved, and movement determines what a forager can reach. Bipedal walking is efficient over distance in a way that knuckle-walking is not. A population that walks can cross open ground between wooded patches at low energetic cost, work a wider catchment of fruiting trees, tubers and water sources, and return. It also frees the hands, which matters for carrying — an armful of fruit or a limb bone moved away from a carcass is a different proposition from eating where you find it. None of that is proven by the prints, but the prints are the earliest firm date for the anatomy that makes it possible. Diet for the species that made them, Australopithecus afarensis, is reconstructed from teeth rather than tracks: mainly plants, with leaves, fruit, seeds, roots, nuts and insects, and probably the occasional small vertebrate. Trees were still used for foraging and for escape. The picture is a forager working both the ground and the canopy, not one committed to either. The trackway has also stopped being a single tidy story. Analysis of the older Site A prints published in 2021 found foot proportions, gait parameters and three-dimensional shapes distinguishable from those at Site G, which implies at least two hominin forms with different feet and different walking styles sharing the same landscape. Earlier work on newly excavated prints likewise indicated marked body size variation. Whatever was walking at Laetoli was not one uniform population. For the food record this is the moment the human lineage becomes a walking forager, with the range and the free hands that implies, several hundred thousand years before the first stone tools and long before fire. The ash that captured the prints did so within hours or days of their being made, which is why they survive at all.
Historical context
Around 3.66 million years ago, hominins were restricted to Africa, no stone-tool industry existed, and fire was not used. The Laetoli landscape was open woodland and grassland dotted with volcanoes, and the ash falls that buried the prints came from nearby Sadiman. Contemporary fauna included three-toed horses, giraffids, rhinoceros and early elephants, whose tracks appear in the same ash layers. The whole hominin population of the planet at this date was a scatter of small groups across eastern and southern Africa, numbering perhaps in the tens of thousands.
Evidence
Archaeological
StrongThe trackways are directly observed, extensively mapped and published, with roughly seventy prints across about 27 metres at Site G.
Dating
StrongThe prints are constrained to 3.66 million years by radiometric dating of the volcanic tuffs that enclose them.
Visual reconstruction
ModerateGait, foot proportions and body size are inferred from print morphology. The 2021 analysis of Site A distinguishes it from Site G, indicating at least two hominin forms rather than one.
Food identification
Insufficient evidenceNo food remains are associated with the trackways. Diet is imported from dental evidence for Australopithecus afarensis elsewhere and is not recorded at this site.
Historical interpretation
InterpretiveThe link from bipedalism to wider foraging range and to carrying is a functional inference. It is well founded energetically but not demonstrated by the prints themselves.
Sources
- 1.Ellison J. McNutt, Kevin G. Hatala, Catherine Miller, et al. (2021). Footprint evidence of early hominin locomotor diversity at Laetoli, Tanzania. Nature 600(7889), 468-471. doi:10.1038/s41586-021-04187-7Scientific literature
- 2.Smithsonian Institution Human Origins Program (2025). Laetoli Footprint Trails; Australopithecus afarensis. Smithsonian National Museum of Natural History. humanorigins.si.edu/evidence/behavior/footprintsModern synthesis
Limitations
- moderatefood identification
This card carries no direct food evidence at all. Every dietary statement is imported from dental studies of Australopithecus afarensis at other sites, and the connection to food is through locomotion and foraging range rather than through anything eaten at Laetoli.
- minorarchaeological attribution
Attribution of the trackways to Australopithecus afarensis is conventional but inferential, resting on the species known from the region at this date. The 2021 Site A analysis indicates at least two hominin forms were present, so a single-species attribution for all Laetoli prints is no longer safe.
