 Lomekwi is near the west bank ofLake Turkana, which is pictured in green on this satellite image. | |
  Approximate location of dig site Shown within Kenya | |
| Alternative name | LOM3 |
|---|---|
| Location | Turkana County,Kenya |
| Region | Rift Valley Province |
| Coordinates | 3°52′27″N35°45′3″E / 3.87417°N 35.75083°E /3.87417; 35.75083 |
| Type | Ancient campsite |
| History | |
| Periods | 3.3 million years ago |
| Cultures | Australopithecus orKenyanthropus |
| Site notes | |
| Excavation dates | 2011 (2011)–present |
| Archaeologists | Sonia Harmand,Stony Brook University, US |
| Public access | Limited |
Lomekwi is anarchaeological site located on the west bank ofTurkana Lake inKenya. It is an important milestone in the history of human archaeology. An archaeological team fromStony Brook University in the United States discovered traces of Lomekwi by chance in July 2011, and made substantial progress four years after in-depth excavations.
Artifacts excavated from Lomekwi date back to 3.3 million years ago, pushing the history of human use and tool making and to about 500,000 years than we had known. The most conspicuous among these cultural relics is a largestone tool with obvious traces of human processing. It looks like a cutting board, but its exact purpose is not clear yet.
The artifacts from Lomekwi have a unique production method and are an independent production style. The archaeological team calls itLomekwian. These tools, which are not highly processed, completely distinguishAustralopithecus from other primates, and it is highly likely that ancient humans already had basic cognitive abilities.
In July 2011, a team of archeologists led bySonia Harmand and Jason Lewis ofStony Brook University, United States, were heading to a site nearLake Turkana, Kenya near whereKenyanthropus platyops fossils had previously been found.[1][2] The group made a wrong turn on the way and ended up in a previously unexplored region and decided to do some surveying. They quickly found some stone artifacts on the site, which they named Lomekwi 3.[1] A year later, they returned to the site for a full excavation.[2] Harmand presented her findings at the annual meeting of the Paleoanthropology Society on April 14, 2015[1] and published the full announcement and results on the cover of Nature on May 21, 2015.[3]
Around 20 well preserved artifacts have been dug up at Lomekwi 3, including anvils, cores, and flakes. An additional 130 artifacts were found on the surface. In one instance, Harmand's team was able to match a flake to its core, suggesting ahominin had made and discarded the tool at the site.[2] The tools were generally quite large – larger than the oldest known stone tools, recovered in theGona area of theAfar Region ofEthiopia, in 1992. The largest weighs 15kg, and may have been used as an anvil.[4] According to Harmand, it appeared that the tool makers had purposely selected large, heavy blocks of strong stone, ignoring smaller blocks of the same material found in the area.[1] She ruled out the possibility that the tools were actually natural rock formations, saying "The artifacts were clearlyknapped and not the result of accidental fracture of rocks".[2] Analysis suggested the cores had been rotated as flakes were struck off.[2] The purpose of the tools found at Lomekwi 3 is unclear, as animal bones found at the site do not bear any sign of hominin activity.[1] This is the greatest expression of lateNeogene technology known to the archaeological record.
Based on the buried artifacts' stratigraphic position (in undisturbed sediment) relative to two layers of volcanic ash and known magnetic reversals, Harmand and her team dated the tools to 3.3 million years ago.[1][2][3] The finds at Lomekwi therefore represent the oldest stone tools ever discovered, predating the Gona tools, dated to 2.6 mya,[5] by 700,000 years.
The date predates the genusHomo by 500,000 years, suggesting this tool making was undertaken byAustralopithecus orKenyanthropus (which was found near Lomekwi 3).[1] Previously, evidence of stone tool use byAustralopithecus has been suggested on the basis of cut-marks on animal bones,[6] but those findings have been debated, with no scientific consensus forming on either side of the debate.[2]
Harmand said the Lomekwi 3 artifacts do not fit into theOldowan tool making tradition and should be considered part of a distinct tradition, which she termed Lomekwian.[1] It has been hypothesized that tool making may have aided in the evolution ofHomo into a distinct genus.[2] However, it is unclear whether the Lomekwian tools are related to those made byHomo species – it is possible the technology was forgotten and later rediscovered.[7]
Independent researchers who have seen the tools are generally supportive of Harmand's conclusions.[7][8]George Washington University anthropologist Alison Brooks said the tools "could not have been created by natural forces ... the dating evidence is fairly solid."[2]Rick Potts, head of theHuman Origins Program at theSmithsonian Institution, said the tools represented a more primitive style than known human-made tools, but something more sophisticated than what modernchimpanzees do. "There's no doubt it's purposeful" toolmaking, he remarked.[7] A PaleoanthropologistZeresenay Alemseged, who was responsible for the earlier research suggestingAustralopithecus had made tools, also backed Harmand's conclusions.[2]