AL 333

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AL 333 (Afar Locality 333) is the scientific name for an unusually extensive find of fossils of the species Australopithecus afarensis , which was discovered in November 1975 in Hadar ( Ethiopia ). The multi-year excavations brought about 240 remains of bones to light, which could be assigned to a total of 17 individuals: nine adults, three adolescents and five children. Like Lucy's , their age has been dated 3.2 million years. The excavation director, Donald Johanson , referred to the find as the First Family .

All bones come from a single layer of earth , the sediments of which were embedded between two layers of volcanic ash and could therefore be reliably dated using the argon-argon method . Most of the bones had been exposed on a steep slope as a result of soil erosion , but hardly any weathering; only 19 fossils have been unearthed in their original location. The bones show no bite marks from predators or scavengers, but are mostly broken. Therefore, it is believed that the bodies were carried away in a river and later washed ashore. As few other bones - fish and rodents - have been found near the Australopithecus fossils, Donald Johanson says there is a good chance that a group of Australopithecus afarensis perished together, possibly a group of relatives. The particular significance of the find is that the members of the group were of different ages but died at the same time. Therefore - also due to the good condition of several quite complete lower and upper jaws - conclusions could be drawn about the development from child to adult and about the size differences of male and female individuals.

The oldest fossil evidence of a foot that is functionally comparable to the human foot also comes from the site AL 333: It is a completely preserved metatarsal bone of Australopithecus afarensis (archive number AL 333-160), its characteristics reveal both the presence of a longitudinal vault and a transverse vault. According to the interpretation of this find, the transition from a grip foot optimized for climbing in branches to an arch that acts as a "shock absorber" when walking upright was already well advanced.

literature

  • Donald Johanson and Maitland A. Edey: Lucy. The beginnings of mankind. 4th edition. Piper, 1992, pp. 256-270, ISBN 3-492-11555-1 .

Web links

Individual evidence

  1. ↑ Maurice Taieb , Donald Johanson , Yves Coppens , Jean-Jacques Tiercelin: Expedition internationale de l'Afar, Ethiopie (4eme et 5eme Campagne 1975–1977): Chronostratigraphie des gisements a hominides Pliocene de l'Hadar et correlations avec les sites prehistoriques de Kana Gona. In: Comptes Rendus de l'Académie des Sciences de Paris. Volume 287, 1978, pp. 459-461
  2. ^ A b Donald Johanson : Lucy and her children. 2nd updated and expanded edition, Elsevier Verlag, Munich 2000, p. 135, ISBN 978-3-8274-1670-4
  3. ↑ Anna K. Behrensmeyer: Paleoenvironmental context of the Pliocene AL 333 “First Family” hominin locality, Hadar Formation, Ethiopia. In: GSA Special Papers. Volume 446, 2008, pp. 203-214
  4. ↑ Philip L. Reno et al .: Sexual dimorphism in Australopithecus afarensis was similar to that of modern humans. In: PNAS . Volume 100, No. 16, 2003, pp. 9404-9409, doi : 10.1073 / pnas.1133180100
    J. Michael Plavcan et al .: Sexual dimorphism in Australopithecus afarensis revisited: how strong is the case for a human-like pattern of dimorphism ? In: Journal of Human Evolution. Volume 48, No. 3, 2005, pp. 313-320, doi: 10.1016 / j.jhevol.2004.09.006
  5. ^ Carol V. Ward, William H. Kimbel, and Donald C. Johanson : Complete Fourth Metatarsal and Arches in the Foot of Australopithecus afarensis. In: Science . Volume 331, No. 6018, 2011, pp. 750-753, doi: 10.1126 / science.1201463