Archaeologists have discovered a 476,000-year-old wooden structure, but its builder remains unknown

Challenging Assumptions About Prehistory

For a very long time, the history of ancient humanity has been analyzed primarily through the lens of stone. This bias can be explained in part by the fact that the names of the three periods of the Stone Age all end with the suffix “-lithic,” since rock withstands the test of time unlike organic materials. It has therefore often been assumed that our most distant ancestors used stone exclusively to craft their tools and structures.

However, research conducted in southern Africa is challenging this scientific certainty. In the tropical forests of northern Zambia, at the Kalambo Falls site along the Kalambo River, a team led by Professor Larry Barham of the University of Liverpool has unearthed exceptional remains from fluvial sediments. These are the remains of a wooden structure cut and shaped using stone tools, accompanied by several wooden utensils buried alongside it.

According to analyses conducted by the archaeological team, this assemblage is at least 476,000 years old. This discovery represents the oldest man-made wooden structure ever recorded, proving that woodworking was mastered long before the emergence of our own species.

The Secrets of Exceptional Geological Preservation

The Kalambo River basin has been well-known within the scientific community since the first excavations conducted by John Desmond Clark in the 1950s and 1960s. This site offers a natural environment particularly conducive to the preservation of prehistoric artifacts. The wooden artifacts discovered were preserved from decay thanks to their prolonged immersion in oxygen-deprived fluvial sediments, while the presence of silica in the water strengthened the material’s structure over the millennia.

Since the wood is so ancient that traditional carbon-14 dating cannot be used, researchers employed the luminescence dating method. This technique involves measuring the natural radioactivity of minerals contained in the surrounding sediments to determine the exact time when these grains were last exposed to sunlight.

The results of these analyses indicate that the wood is at least 476,000 years old. This dating significantly pushes back the chronological limits of human construction and predates by a wide margin the oldest known Homo sapiens fossils, discovered in Morocco and dated to approximately 300,000 years ago.

Unprecedented Prehistoric Engineering

The most striking aspect of this discovery lies in the technical assembly of the pieces. As reported in a study published in 2023 in the journal Nature by Larry Barham and his colleagues, archaeologists unearthed “two logs that fit together and are connected transversely by an intentionally carved notch.” The authors emphasize that “this construction has no known equivalent in the African or Eurasian Paleolithic.”

Admittedly, older worked wood had already been discovered, such as the fragment of a polished plank from the Acheulean site of Gesher Benot Ya’aqov in Israel, dated to more than 780,000 years ago. However, that was a single, isolated object. At the Kalambo Falls, this is the first time evidence has been found of the intentional fitting of two tree trunks to create an engineering structure.

To confirm that these notches were the result of human action rather than natural erosion, the team created three-dimensional digital models. These 3D models were manipulated virtually to study the tool marks without risking damage to the artifacts. Experiments conducted with modern wood samples also demonstrated that while water can smooth edges, it cannot under any circumstances carve deliberate notches similar to those found on the remains.

Unknown Authors and Presumed Functions of the Structure

For decades, wood was considered a secondary material in hominin toolmaking, used primarily to make spear shafts, axe handles, or firewood. Ancestors such as Homo erectus were viewed as nomads unlikely to have built permanent structures. The identity of the builders of Kalambo remains undetermined: Homo erectus, who lived between 2 million and 100,000 years ago, is among the likely candidates, as is Homo heidelbergensis, whose skull was discovered elsewhere in Zambia. Other modified wooden objects have also been found at Florisbad, in South Africa, alongside the remains of a later species, Homo helmei.

Structurally, these interlocking pieces function similarly to wooden building blocks for children, where notches allow the elements to lock together without slipping under pressure. This method ensured the stability of the structure, although it is unlikely that hominins from half a million years ago built entire houses.

Researchers suggest that this wooden structure may have been designed to serve as the foundation for a platform, a footbridge across the wetland, a storage area, or a rudimentary shelter. These elements demonstrate a deliberate effort to create a stable living environment.

A Reassessment of Prehistoric Cognition

This scientific breakthrough profoundly changes our understanding of the technical and cognitive abilities of early humans. As Larry Barham explains, “The interlocking logs demonstrate the combination of two or more pieces to create a structure, which enhances our understanding of the technical cognition of these toolmakers.”

The researcher also adds that “exceptional preservation conditions offer us this glimpse into the ability of hominins—previously viewed as mobile hunter-gatherers with limited technological diversity—to create a built environment.” This ability to transform their surroundings challenges the traditional model of the evolution of human skills.

Due to the exceptional significance of its archaeological data, the Kalambo Falls site was nominated in 2026 for inclusion on UNESCO’s Tentative List of World Heritage Sites for Zambia. This nomination underscores the site’s major importance in the history of human technology.

Source: popularmechanics.com

Archaeologists have discovered a 476,000-year-old wooden structure, but its builder remains unknown