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Introduction to Lomekwi 3 Archaeological Findings

  • Study Citation: Harmand et al. "3.3-million-year-old stone tools from Lomekwi 3, West Turkana, Kenya." DOI:10.1038/nature14464

  • The article discusses pioneering findings from Lomekwi 3 site, dated at 3.3 million years old, significantly predating known stone tools attributed to early Homo species.

Historical Context and Theoretical Background

  • Conventional Wisdom: Early hominin stone tool development has been traditionally linked to the genus Homo and correlated with climate change and savannah spread.

  • Early Discoveries:

    • 1964: Discovery of early fossils resembling Homo at Olduvai Gorge, Tanzania, alongside the Oldowan stone tool culture, initially assigned to Homo habilis.

    • The hypothesis posited that only Homo species had the cognitive capability to develop sharp-edged stone tools.

  • Revised Chronology:

    • First Oldowan tools were initially dated at 2.6 million years, with earliest Homo fossils placed at 2.4–2.3 million years ago.

    • Pre-Oldowan artefacts and speculations regarding pre-2.6 Ma knapping practices emerge from finds in Ethiopia and other sites.

Discovery of Lomekwi 3

  • Fieldwork Context: The West Turkana Archaeological Project (WTAP) was initiated in 2011 to investigate the Nachukui Formation.

  • Findings at Lomekwi 3:

    • Initial surface artefacts included 28 lithic pieces, with systematic excavation revealing 18 additional tools and 11 fossils in situ over a 13 m² area.

    • The assemblage shows a spatio-temporal association with Pliocene hominin fossils, indicating advanced tool-making behavior.

    • The Lomekwi 3 technological behavior reflects a burgeoning understanding of stone fracture mechanics, showcasing early core reduction and battering methods.

Geological and Radiometric Context

  • Geochronological Framework:

    • Lomenkwi Member of the Nachukui Formation bracketed between voluminous tuffs: a-Tulu Bor Tuff (3.44 ± 0.02 Ma) and Lokalalei Tuff (2.53 ± 0.02 Ma).

    • Age estimation of 3.3 Ma based on sediment accumulation rates calculated between tuffs and correlating geological ages, confirmed by isotopic analysis of pedogenic carbonates.

  • Palaeoenvironmental Context:

    • Stable Carbon Isotopes Analysis: Mean δ13CVPDB value indicates a woodland ecosystem with significant tree cover (approximately 47%).

    • The environment contrasted with drier grassland habitats observed in later periods.

The Lomekwi 3 Archaeological Site

  • Site Description: LOM3 is characterized by geomorphic features conducive to sediment preservation, with distinct layers signaling different depositional environments.

  • Site Stratigraphy:

    • Artefacts appear in slightly redistributed primary context, suggesting either minimal disturbance or close proximity preservation concerning original knapping activities.

Technology of Lomekwi 3 Stone Tools

  • Assemblage Composition:

    • Total of 149 lithic artefacts: 83 cores, 35 flakes (whole and broken), accessory tools (anvils and percussors), and more.

    • Predominant raw materials: Basalt (34.90%) and phonolite (34.23%), showing selective use of local resources.

  • Knapping Techniques:

    • Cores exhibit mostly unifacial partial exploitation; some demonstrate bifacial techniques.

    • Knapping accidents are evident, including hinge and step flake terminations, indicating a learning curve in the knapping process.

    • Experimental replication demonstrated the use of passive hammer and bipolar techniques, implying a complex understanding of stone tool production.

Comparative Analysis with Other Assemblages

  • Size Comparison: LOM3 artefacts are notably larger than those from later Oldowan and chimpanzee tool contexts, with significant implications for understanding hominin hand biomechanics.

  • Multifunctionality: Tools were adapted for diverse uses, showing a clear difference in functionality from typical primate tool usage, hinting at cognitive advances among early hominins.

Implications for Hominin Evolution

  • The discoveries at Lomekwi 3 suggest that noteworthy cognitive and physical adaptations necessary for stone tool production occurred much earlier than recorded with early Homo.

  • Cerebral Evolution: Significant motor control evidenced implies earlier neurological adaptations in the hominin lineage predating known Homo fossil records.

  • Naming Proposal: The term ‘Lomekwian’ is proposed to categorize this distinct technological phase, emphasizing its age and importance in the archaeological narrative.