Lomekwi

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Lomekwi is the name for a group of paleoanthropological and archaeological sites on the west bank of Lake Turkana in Kenya . For the lithostratigraphic excavation horizon of these sites, referred to in the specialist literature as "Lomekwi Member", an age of 3.36 to 2.52 ± 0.05 million years was shown in 1988. At one of these sites in 1999, the fossil remains of a skull were recovered, which in 2001 was identified as the holotype of a new genus of hominini , Kenyanthropus ; the age of these fossils was at least 3.3 million years.

Ten years later, stone tools of the same age were recovered from a neighboring site , which were interpreted as evidence of an independent archaeological culture , called Lomekwian , as suggested .

Preliminary considerations

The discovery of the 3.3 million year old, Australopithecus - like fossils of Kenyanthropus gave rise to the consideration whether stone tools were already used during the lifetime of these individuals. As the oldest, certainly occupied stone tools were around 2000 so-called debris devices from Oldowan type of Kada Gona in Ethiopia , which had been dated at around 2.6 million years 1997th However, these tools are already sharpened or sharpened by deliberately chipping off parts of the original stone, so that paleoanthropologists have long assumed that the first stone tools must be simpler and older than those of the Oldowan type.

In addition, in 2010 an international team of researchers published the discovery of 3.3 million year old scratches and cuts on fossil animal bones from the Dikika site in Ethiopia , which, according to their interpretation, prove, among other things, that Australopithecus afarensis was meat from ribs - and leg bones scratched.

Based on such considerations and discoveries, the West Turkana Archaeological Project started looking for stone tools in 2011. The Lomekwi 3 (LOM3) site was particularly promising for testing this hypothesis , where material from the "Lomekwi member" emerges from soil erosion on a slightly sloping hillside ; from the excavation horizon in which the lower jaw KNM-WT 38350 had been located, which was added to the first description of Kenyanthropus as a paratype .

Tool finds

As early as 2011, 28 artifacts were collected at the LOM3 site (surface finds ), and another artifact was discovered in situ . In 2012, a further 18 stone tools were uncovered on an excavation area of ​​13 square meters, and around 100 artefacts were collected in the immediate vicinity of the excavation site, which presumably had come to the surface through soil erosion. The professional assessment of the finds showed that they differ both from the stone tools found in wild chimpanzees (→ tool use in chimpanzees ) and from the stone tools of the earliest Oldowan culture.

In comparison with the Oldowan culture, the LOM3 finds were described as clearly less developed. Apparently, cuts were brought about less deliberately than in the Oldowan culture - instead of holding two stones in your hands and hitting each other, the LOM3 finds were probably made by hitting a stone against a lying anvil . All LOM3 finds are also larger than those of the Oldowan culture.

The cause of these differences were the different cognitive abilities of the producers of these tools, which were reflected in different manual skills. Furthermore, in the description of the LOM3 finds published in 2015, it was argued that classifying these finds as the Oldowan type would obscure these different cognitive abilities. Therefore, the new designation "Lomekwian" was proposed for the LOM3 finds.

Hominin tooth finds

It is unclear what kind of hominini produced these LOM3 artifacts; What is certain is that it cannot have been a species of the genus Homo , as its earliest fossil record - the fossil LD 350-1 - is around half a million years younger. In 2020, the discovery of 67 mostly individually collected, hominine teeth was reported, the size of which is comparable to that of Australopithecus afarensis and Australopithecus deyiremeda . However, some features of these 3.5 to 3.2 million year old teeth, which were recovered between 1982 and 2009, differ from the features of both species to such an extent that they cannot be assigned to a specific species. A comparison with Kenyanthropus platyops also gave no evidence of a proximity to this species, since the teeth of its type specimen are too badly damaged and too little bone material was passed down with the 67 teeth.

Web links

Individual evidence

  1. ↑ John H. Harris , Frank H. Brown and Meave G. Leaky : Stratigraphy and Paleontology of Pliocene and Pleistocene Localities West of Lake Turkana, Kenya. Natural History Museum of Los Angeles County, Los Angeles, California, 1988, pp. 14–15 (= Contributions in Science. No. 399 of October 28, 1988), full text (PDF)
  2. ↑ a b c Sonia Harmand et al .: 3.3-million-year-old stone tools from Lomekwi 3, West Turkana, Kenya. In: Nature. Volume 521, No. 7552, 2015, pp. 310-315, doi: 10.1038 / nature14464
  3. ↑ Sileshi Semaw et al .: 2.5-million-year-old stone tools from Gona, Ethiopia. In: Nature . Volume 385, 1997, pp. 333-336, doi: 10.1038 / 385333a0
  4. ↑ Sileshi Semaw et al .: 2.6-million-year-old stone tools and associated bones from OGS-6 and OGS-7, Gona, Afar, Ethiopia. In: Journal of Human Evolution. Volume 45, 2003, pp. 169–177, doi: 10.1016 / S0047-2484 (03) 00093-9 , full text (PDF) with images of the rubble devices
  5. ↑ Erella Hovers: Tools go back in time. In: Nature. Volume 521, No. 7552, 2015, pp. 294-295, doi: 10.1038 / 521294a
  6. ↑ Shannon P. McPherron et al .: Evidence for stone-tool-assisted consumption of animal tissues before 3.39 million years ago at Dikika. In: Nature. Volume 466, 2010, pp. 857-860, doi : 10.1038 / nature09248
  7. ^ Website of the West Turkana Archaeological Project
  8. ↑ Susana Carvalho et al .: Tool-composite reuse in wild chimpanzees (Pan troglodytes): archaeologically invisible steps in the technological evolution of early hominins? In: Animal Cognition. Volume 12 (Suppl. 1), 2009, pp. 103-114, doi: 10.1007 / s10071-009-0271-7
  9. ↑ World's oldest stone tools discovered in Kenya. On: sciencemag.org April 14, 2015
  10. ↑ Matthew M. Skinner, Meave G. Leakey, Louise N. Leakey et al .: Hominin dental remains from the Pliocene localities at Lomekwi, Kenya (1982-2009). In: Journal of Human Evolution. Volume 145, 2020, 102820, doi: 10.1016 / j.jhevol.2020.102820 .