Paranthropus aethiopicus

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Paranthropus aethiopicus
The "Black Skull" of Paranthropus aethiopicus (replica)

The " Black Skull " of Paranthropus aethiopicus
(replica)

Temporal occurrence
Pliocene
2.7 to 2.3 million years
Locations
Systematics
Human (Hominoidea)
Apes (Hominidae)
Homininae
Hominini
Paranthropus
Paranthropus aethiopicus
Scientific name
Paranthropus aethiopicus
( Arambourg & Coppens , 1968)

Paranthropus aethiopicus is a species of the extinct genus Paranthropus from the line of development of the hominini , whichoccurredin East Africa around 2.8 to 2.3 million years ago. The species of the genus are included in the Australopithecina group and probably represent an evolutionary sideline to the genus Homo .

The delimitation of the species from other species of the genus Paranthropus and the genus Australopithecus is controversial. The fossils are therefore also referred to as Australopithecus aethiopicus by some researchers .

Naming

Paranthropus is an artificial word . The name of the genus is derived from ancient Greek ἄνθρωπος anthropos , German 'human' and para 'beside', 'deviating from'; the epithet aethiopicus refers to Ethiopia , where in 1967 the first fossil related to this species was discovered in 1967 , which was also the first find in Ethiopia of a fossil representative of the hominini. Paranthropus aethiopicus therefore means “fellow human being from Ethiopia”, in the sense of “arranged in the family tree next to the genus of humans”.

Initial description

The holotype of Paranthropus aethiopicus is a slightly damaged lower jaw bone with missing crowns (archive number Omo 18-1967-18), which was discovered on July 7, 1967 by the French researcher René Houin in layer C of the Shungura formation on the Omo River - the in which flows into Lake Turkana - had been discovered. As early as August 16, 1967, this fossil was presented at a meeting of the Académie des Sciences by Camille Arambourg and Yves Coppens and attributed to the species Paraustralopithecus aethiopicus (“originating from Ethiopia and deviating from Australopithecus ”), which they “temporarily” introduced . However, this designation was only shown as “valid” in a second publication; In this first description , again only two printed pages long , it was admitted - as previously to the Académie - that at first glance the lower jaw resembles Australopithecus africanus in particular , but the particularly strong ascending branch of the lower jaw (Ramus mandibulae) clearly softens from Australopithecus and especially from Paranthropus boisei from.

More finds

As evidence of a new species, the fragment Omo 18-1967-18 remained controversial until 1986, mainly due to the lack of tooth crowns, because the structure of the teeth in particular can be used to deduce that many mammalian fossils belong to a certain species. Due to its condition, the lower jaw Omo 18-1967-18 proved to be unsuitable for the classification of a certain species. In 1986, however, Alan Walker and Richard Leakey described the " Black Skull " ("Black Skull" - see figure on the right; archive number KNM-WT 17,000), which they discovered in 1985 west of Lake Turkana (Kenya) in the journal Nature , but which they are the sister species Attributed to Australopithecus boisei . This publication immediately led to a review of various hypotheses on relationships between the various species of the genera Australopithecus and Paranthropus as well as the assignment of individual finds to certain species. As a result, the lower jaw Omo 18-1967-18 from Ethiopia, the presumably the same old "black skull" and some other individually found teeth and skull fragments as well as the lower jaw KNM-WT 16005 were identified as Paranthropus aethiopicus . However, this assignment was not based on clear common anatomical features (the "black skull" has no lower jaw, there is no upper jaw for the Ethiopian holotype), but solely on the basis of the body size, the similar age and the not too great geographical distance of the sites. "It was assumed that at any given point in time and in a certain region only one single species of hominid with a certain body size existed"; But since even today three hominid species with partly overlapping body size still live next to each other in certain regions west of the Rift Valley ( gorillas , chimpanzees and humans ), "this classification, which is based on such criteria, seems very questionable."

features

The "Black Skull" in side view

The species Paranthropus aethiopicus was defined on the basis of the mandibular fragment Omo 18-1967-18, which has narrow incisors and whose left and right rows of teeth converge towards the front. The upper jaw of the black skull, on the other hand, has long, parallel rows of teeth, and the distance between the left and right canine teeth is relatively wide, from which it can be concluded that there are wide incisors; these differences suggest that “the holotype specimen and the black skull are different biological species.” However, the shape of the incisors distinguishes the “black skull” from all other Paranthropus species. In contrast, the canines of his upper jaw - as in other Paranthropus species - are relatively small, the molars are large and flat ground.

The face of Paranthropus aethiopicus is, as far as this can be derived from the "black skull", quite flat and has an extremely developed snout and due to the "pronounced alveolar prognathy", in which the incisor rows are more horizontally than vertically embedded in the jaw a concave face. Although other Australopithecines such as Australopithecus afarensis also show prognathy, it is "more pronounced" in Paranthropus aethiopicus and is a reliable distinguishing feature.

Similar to the gorilla men living today, there is a noticeably towering crest at the top, in the middle of the skull , to which the masticatory muscles attach. A brain volume of 410 cm³ was already calculated for the black skull in its first description, which roughly corresponds to the mean brain volume of a modern chimpanzee .

Related finds of skull bones and bones below the skull have not yet been discovered, so that there are only guesses about his body structure. These assumptions are based on skeletal bones that come from layers containing fossils of the same age and are of a suitable size. From this it was deduced that the owners of these bones were able to move on the ground as well as climb trees, but not yet "walked on two legs in the habitual fashion." The body height was estimated at about 1.30 meters, the body weight to 30 to 40 kg.

habitat

The Fund layers are based on radiometric dating and because paleomagnetic analysis to be reliable datable since it above and below the fossil-bearing strata - before 2.5 million years - repeatedly came to ash deposits by volcanic eruptions. In the same Fund layers many were accompanying finds recovered, so among other bones of lion , striped hyena and caracal , of elephant , giraffe and rhino , of Moorantilope ( Menelikia ), Gnu and goat , of Baboon ( Parapapio ) and suppression coffee ( Paracolobus ). In addition, fossils were discovered in these strata that belong to another - not clearly identified - hominid species; Australopithecus garhi and Homo rudolfensis are equally old species . Reedbuck and waterbuck are particularly common , which is why it is assumed that Paranthropus aethiopicus lived in grasslands that were at least temporarily flooded and in a climatic zone that was similar to today's East Africa.

The large and heavily worn molars of the black skull and its bone crest - on which the strong jaw muscles attached - point to a habitat in which mainly hard vegetable foods served as food. The large incisors may have been used to peel bark off plant stems. At the time when Paranthropus aethiopicus first appeared 2.8 million years ago, a change in their dentition (thickening of the tooth enamel ) was also found in several other animal species , as well as evidence of more frequent periods of drought in what is now southern Ethiopia.

classification

Hypothesis on the evolution of the australopithecines , as represented by Friedemann Schrenk , for example, based on the current finds .

The classification of Paranthropus aethiopicus in the family tree of the hominini is unclear. Some researchers interpret this species as a precursor of the somewhat younger species Paranthropus boisei and Paranthropus robustus . Other researchers argue that the genus Paranthropus is polyphyletic , meaning that the species assigned to it have no common ancestor. What is certain, however, is that Paranthropus is to be regarded as a branch of the evolutionary line that led to the genus Homo .

It is possible that the fossil BOU-VP-12/130 - the type specimen of Australopithecus garhi - belongs to the same group of forms as the fossils associated with Paranthropus aethiopicus ; common features of the discovered lower jaw indicate this. Should this be the case, the fossils identified as Australopithecus garhi would have to be renamed and referred to as Paranthropus aethiopicus .

See also

literature

  • Jonathan G. Wynn, Zeresenay Alemseged , René Bobe et al .: Isotopic evidence for the timing of the dietary shift toward C4 foods in eastern African Paranthropus. In: PNAS . Online advance publication of August 24, 2020, doi: 10.1073 / pnas.2006221117 .
  • Enquye W. Negash, Zeresenay Alemseged, René Bobe et al .: Dietary trends in herbivores from the Shungura Formation, southwestern Ethiopia. In: PNAS. Online advance publication of August 24, 2020, doi: 10.1073 / pnas.2006982117 .

Web links

Commons : Paranthropus aethiopicus  - collection of images, videos and audio files

Individual evidence

  1. ↑ a b Camille Arambourg and Yves Coppens : Découverte d'un Australopithécien nouveau dans les gisements de l'Omo (Ethiopia). In: South African Journal of Science. Volume 64, 1968, pp. 58-59
  2. ↑ Alice Roberts: Evolution. The Human History. Dorling Kindersley, London 2011, p. 92, ISBN 978-1-4053-6165-1
  3. ^ Camille Arambourg and Yves Coppens: Sur la découverte, dans le Pléistocène inférieur de la vallée de l'Omo (Ethiopie), d'une mandibule d'Australopithécien. In: Comptes rendus hebdomadaires des séances de l'Académie des Sciences. Série D. Volume 265, August 1967, pp. 589-590 [published in print 1968].
  4. ^ Alan Walker , Richard E. Leakey , John M. Harris, and Francis H. Brown: 2.5-Myr Australopithecus boisei from west of Lake Turkana, Kenya. In: Nature . Volume 322, 1986, pp. 517-522; doi: 10.1038 / 322517a0
  5. ↑ Eric Delson : Human phylogeny revised again. In: Nature. Volume 322, 1986, pp. 496-497; doi: 10.1038 / 322496b0 , full text (PDF) ( Memento from August 20, 2008 in the Internet Archive )
  6. ^ Francis Clark Howell , Paul Haesaerts and Jean de Heinzelin: Depositional environments, archaeological occurrences and hominid from Members E and F of the Shungura Formation (Omo basin, Ethiopia). In: Journal of Human Evolution. Volume 16, 1987, pp. 665-700, doi: 10.1016 / 0047-2484 (87) 90019-4
  7. ↑ Gary J. Sawyer, Viktor Deak: The Long Way to Man. Life pictures from 7 million years of evolution. Spektrum Akademischer Verlag, Heidelberg 2008, p. 51
  8. ^ Gary J. Sawyer, Viktor Deak: The Long Way to Man, p. 51
  9. ↑ William H. Kimbel and Tim White determined “the prognathism in KNM-WT 17000 (Walker et al., 1986) at 45 ° based on the craniogram made available by Alan Walker”. F. Grine (Ed.): Evolutionary History of the "robust" Australopithecines . New Brunswik, New Jersey: Transaction publishers 1998, p. 185
    D. Dykhoff, J. Reese, G. Fander: Industrial production development: an empirical-descriptive analysis. Springer, 2nd ed. 1994, p. 34
  10. ↑ Martina Kleinau: In the footsteps of Lucy and Co. The long way to Homo sapiens. Grin-Verlag 2008, p. 227
  11. ^ A b Bernard Wood , Nicholas Lonergan: The hominin fossil record: taxa, grades and clades. In: Journal of Anatomy . Volume 212, No. 4, 2008, p. 359, doi: 10.1111 / j.1469-7580.2008.00871.x , full text (PDF; 285 kB) ( Memento from October 29, 2013 in the Internet Archive )
  12. ^ Gary J. Sawyer, Viktor Deak: The Long Way to Man, p. 49
  13. ↑ Thorolf Hardt, Bernd Herkner and Ulrike Menz: Safari to the primitive man. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart 2009, p. 113, ISBN 978-3-510-61395-3
  14. ^ Faysal Bibi et al .: Ecological change in the lower Omo Valley around 2.8 Ma. In: Biology Letters. Volume 9: 20120890, December 12, 2012, doi: 10.1098 / rsbl.2012.0890
  15. ↑ David S. Strait et al .: A reappraisal of early hominid phylogeny. In: Journal of Human Evolution. Volume 32, 1997, pp. 17-82, doi: 10.1006 / jhev.1996.0097
  16. ↑ Randall R. Skelton and Henry M. McHenry: Evolutionary relationships among early hominids. In: Journal of Human Evolution. Volume 23, 1992, pp. 309-349, doi: 10.1016 / 0047-2484 (92) 90070-P
    Daniel E. Lieberman, Bernard A. Wood and David R. Pilbeam : Homoplasy and early Homo: an analysis of the evolutionary relationships of H. habilis sensu stricto and H. rudolfensis. In: Journal of Human Evolution. Volume 30, 1996, pp. 97-120, doi: 10.1006 / jhev.1996.0008
  17. ↑ Winfried Henke , Hartmut Rothe : Stammesgeschichte des Menschen, p. 140