LD 350-1

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LD 350-1 is the scientific name for a lower jaw fragment that was assigned to the genus Homo by its discoverers in March 2015 and was dated to an age of 2.8 - 2.75 million years. The find is - before the lower jaw UR 501 - the earliest evidence of the genus Homo to be discovered .

The fossil was discovered on January 29, 2013 by Chalachew Seyoum, an Ethiopian student studying in the USA, at the Ledi-Geraru excavation site in the Afar region of Ethiopia . It is the left half of the lower jaw of an adult, in which the canine , both premolars and all three molars - mostly with crowns and roots - are preserved; The structure of the lower jawbone is also well preserved. The find resembles the lower jaw UR 501 and, like this, exhibits a combination of morphological features that are characteristic partly of the older genus Australopithecus and partly of the genus Homo .

The analysis of the fossil published in Science admits that the lower jaw is only around 200,000 years younger than the most recent find of an Australopithecus afarensis from the Hadar site around 50 kilometers southwest . In addition, the size of the teeth and the lower jaw bone as well as other features of the bone match those of Australopithecus afarensis . Numerous other features - especially the morphology of the tooth crowns - are similar to those of early homo .

However, the authors of the analysis expressly refrain from assigning them to one of the two homo species ( Homo rudolfensis or Homo habilis ), which are fossilized in Africa over 2 million years ago . At the same time, however, it was also left open whether the fossil is to be interpreted as evidence of a species of the genus Homo that has yet to be described .

The fossil comes from an era in which the climate in East Africa became increasingly drier due to the movements of the tectonic plates . In addition, volcanic deposits in the soil of the site point to increased volcanic activity in a landscape that at the time was similar to today's Serengeti . The associated ecological upheavals - so the argument of the researchers - could have contributed to the development of one of the species of the Australopithecus genus into the Homo genus .

Web links

Individual evidence

  1. ↑ Brian Villmoare et al .: Early Homo at 2.8 Ma from Ledi-Geraru, Afar, Ethiopia. In: Science . Volume 347, No. 6228, 2015, pp. 1352–1355, doi: 10.1126 / science.aaa1343
  2. ^ William H. Kimbel and Lucas K. Delezene: "Lucy" redux: A review of research on Australopithecus afarensis. In: American Journal of Physical Anthropology. Volume 140, Supplement 49, 2009, pp. 2-48, doi: 10.1002 / ajpa.21183
  3. ↑ Ann Gibbons on sciencemag.org of March 4, 2015: Deep roots for the genus Homo. ( Memento from March 5, 2015 in the Internet Archive )
  4. ↑ Erin N. DiMaggio et al .: Late Pliocene fossiliferous sedimentary record and the environmental context of early Homo from Afar, Ethiopia. In: Science. Volume 347, No. 6228, 2015, pp. 1355–1359, doi: 10.1126 / science.aaa1415
  5. ↑ Earliest known fossil of the genus Homo dates from 2.8 to 2.75 million years ago. On: eurekalert.org of March 4, 2015.
  6. ^ Joshua R. Robinson et al .: Late Pliocene environmental change during the transition from Australopithecus to Homo. In: Nature Ecology & Evolution. Volume 1, Article No. 0159, 2017, doi: 10.1038 / s41559-017-0159
    Grassy beginning for earliest Homo. On: eurekalert.org from May 15, 2017