Southwestern Nigeria is known for its vibrant cultures and long historical traditions, yet its far older human record stretches back thousands of years beyond written memory. In present day Ondo State, a modest rock shelter known locally as Ihò Eléérú, often written as Iwo Eleru, preserves one of the most important archaeological sites in West Africa.
Within its layered deposits, archaeologists uncovered a human burial associated with the Late Stone Age, alongside an immense quantity of stone artefacts that testify to repeated occupation over a very long period. Together, these discoveries anchor deep human history to a specific place in Nigeria.
The Setting, A Forest and Savanna Borderland
Iwo Eleru lies within a forest savanna transition zone in southwestern Nigeria. This ecological position shaped how ancient communities used the landscape. Over the past 14,000 years, the broader region shifted between forested and more open environments as global climates changed at the end of the Ice Age.
Recent environmental research published in iScience indicates that while surrounding areas experienced fluctuations, forested patches likely persisted locally near the shelter for long periods. This created a stable microenvironment within a changing regional mosaic, making the location attractive for repeated human occupation across generations.
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The 1965 Excavation and the Human Burial
The site entered the academic record through excavations led by Thurstan Shaw and his team in 1965. During this work, the excavators uncovered a human burial within deposits associated with Late Stone Age material.
The burial was recorded at a depth of approximately 82 to 100 centimetres below the surface. The remains included parts of the skull, specifically a calvaria, along with additional skeletal fragments. The burial was documented as part of the archaeological sequence rather than a later disturbance.
This discovery immediately placed Iwo Eleru among the most important prehistoric sites in Nigeria.
Dating to the End of the Ice Age
Scientific dating has been central to understanding the burial’s age.
Radiocarbon dating on charcoal associated with the burial produced an estimate of 11,200 plus or minus 200 years before present. When calibrated, this places the burial at roughly 13,000 years ago, within the terminal Pleistocene, the final phase of the last Ice Age.
Later uranium series analysis conducted on a bone fragment supported a terminal Pleistocene age range of approximately 11.7 to 16.3 thousand years ago. These results firmly situate the individual in the period when global climates were shifting toward the warmer conditions of the Holocene.
This makes Iwo Eleru one of the clearest examples of Late Stone Age human presence in West Africa near the end of the Ice Age.
Hundreds of Thousands of Stone Tools
The burial is only part of the story. Excavations at Iwo Eleru produced an extraordinary lithic assemblage. Archaeological reports describe more than 500,000 artefacts recovered from the shelter.
Such scale reflects sustained stone tool production and repeated visits to the site. Flakes, cores, and other lithic debris accumulated over time, creating a deep archaeological record of human activity.
This concentration of material demonstrates that Iwo Eleru was not an isolated or short term stop. It was a place people returned to repeatedly, carrying out everyday tasks and leaving behind the physical traces of their lives.
A Skull That Expanded Understanding of African Prehistory
In 2011, Harvati and colleagues published a detailed morphometric study of the Iwo Eleru calvaria. Their analysis showed that the skull displays a mosaic of features. Some characteristics align with modern human populations, while aspects of vault shape differ from many recent human samples.
The findings contribute to broader discussions about the complexity of human population history in Africa during the Late Pleistocene. Rather than fitting neatly into simple categories, the Iwo Eleru skull reflects the regional diversity that characterized ancient African populations.
The site highlights the depth and variation of human history in West Africa during a time of environmental and cultural change.
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Environmental Change and Human Adaptation
Environmental research at Iho Eleru provides a window into how ancient communities adapted to shifting landscapes. The multiproxy study published in 2023 integrates botanical, sedimentary, and chronological evidence to reconstruct environmental change over the last 14,000 years.
The research suggests that while regional conditions shifted toward a more open savanna ecotone during the mid Holocene warm period around 6,000 years ago, forested areas likely persisted locally around the shelter. Later reforestation and increasing human land use shaped the modern landscape.
This environmental continuity helps explain why Iwo Eleru remained significant across millennia.
Deep Time in Nigerian History
Iwo Eleru demonstrates that southwestern Nigeria was inhabited thousands of years before written history, long before kingdoms, trade networks, and recorded chronicles. It shows that Late Stone Age communities lived, worked, and buried their dead in this landscape at the close of the Ice Age.
The site stands as one of the most important archaeological locations in Nigeria for understanding deep human antiquity in West Africa. Its burial, stone tool record, and environmental context together reveal a history rooted in both adaptation and continuity.
Author’s Note
Iwo Eleru reveals that Nigeria’s history stretches back at least 13,000 years, to a time when Late Stone Age communities lived in a forest savanna borderland at the end of the Ice Age, leaving behind a burial and hundreds of thousands of stone tools that firmly anchor deep human presence in southwestern Nigeria.
References
Harvati, K., Stringer, C., Grün, R., Aubert, M., Allsworth Jones, P., Folorunso, C. A., 2011. The Later Stone Age calvaria from Iwo Eleru, Nigeria, morphology and chronology. PLOS ONE.
Cerasoni, J. N., Hallett, E. Y., Orijemie, E. A., and colleagues, 2023. Human interactions with tropical environments over the last 14,000 years at Iho Eleru, Nigeria. iScience.
Allsworth Jones, P., Harvati, K., Stringer, C., 2010. The archaeological context of the Iwo Eleru cranium from Nigeria and preliminary results of new morphometric studies. BAR International Series chapter.
