Paranthropus

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Paranthropus
The fossil KNM WT 17000 from Paranthropus aethiopicus (replica)

The fossil KNM WT 17000 from Paranthropus aethiopicus ( replica )

Temporal occurrence
Upper Pliocene to Pleistocene
2.8 to 1.0 million years
Locations
Systematics
Old World Monkey (Catarrhini)
Human (Hominoidea)
Apes (Hominidae)
Homininae
Hominini
Paranthropus
Scientific name
Paranthropus
Broom , 1938
species

Paranthropus is a fossil genus of Hominini in the family of apes (Hominidae). The Paranthropus - species are in a group of australopithecine expected and likely represent a evolutionary sideline to the genus Homo is Common features of these species are particularly their large. Molars .

Naming

Paranthropus is an artificial word . The name of the genus is derived from ancient Greek ἄνθρωπος anthropos , German ' human ' and para ('next to', 'different from'). The epithet of the type species, Paranthropus robustus , alludes to the 'robust' physique. Paranthropus robustus therefore means “robust fellow human”, in the sense of “arranged in the family tree next to the human species”.

Initial description

The holotype of the genus and at the same time the type species Paranthropus robustus is a partially preserved skull (archive number TM 1517) first described by Robert Broom in August 1938 , the remains of which had previously been discovered near Sterkfontein in June 1938 .

The skull was discovered by a student living in the area who had seen large parts of a skull and a lower jaw protruding from the ground on a hill, away from the Sterkfontein caves. The boy knocked off some accessible parts and gave a fragment from the area of ​​the palate with a large molar still attached to the fossil dealer George Barlow, who passed the find on to Robert Broom. Broom noticed that several of the fossil's teeth had recently been broken off, and he suspected that other fragments might be present at the fossil's location. Thereupon he immediately went in search of the boy who actually still had four teeth of the fossil in his jacket pocket.

At the site, Broom also discovered the other suspected fragments; After they had been cleaned, they could be joined together to form an almost complete palatal bone with almost all the teeth of the upper jaw and the left half of the skull, and the right half of the lower jaw was also discovered. Based on these findings, according to the initial description, the original size of the skull could be estimated, which, according to Broom, was larger than the majority of male chimpanzees living today and almost as big as most female gorillas living today . Overall, however, the structure of the skull is very different from that of the great apes living today, and it also deviates from all the characteristics of other fossil species described so far. The face was very flat and much shorter than that of the gorillas. According to Broom, the brain volume of the type specimen could have been around 600 cm³.

features

Paranthropus probably did not walk upright all the time, but moved on all fours at least at times. The brain volume is 500 cm 3 to 100 cm 3 greater than that of today's chimpanzees and bonobos . Your body size is not exactly known, as no completely preserved leg or arm bones have been discovered that would allow a reliable conclusion about the size; Estimates amount to a maximum of 1.50 m, which maintains about the size standing extant would correspond to chimpanzees. Paranthropus lived at the same time as the earliest members of the genus Homo .

The species of the genus Paranthropus are interpreted by some paleoanthropologists as late species of the genus Australopithecus and are sometimes referred to as "robust Australopithecines". One of their characteristics compared to the "graceful" Australopithecus species is an increasing anatomical specialization in the direction of hard-fibred plant food. This is particularly evident in a massive lower jaw with large premolars and molars as well as a bone ridge on the roof of the skull , which served as a base for a pronounced masticatory muscles . A study published in 2011 came to the result that Paranthropus boisei had about 77 ± 7% more C4 plants in its metabolism than all hominins examined so far and was therefore specialized in eating grass. 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.

Computed tomographic analyzes of the interior of skull bones showed that the internal morphological characteristics of Paranthropus robustus and Paranthropus boisei are identical and that both were closely related sister species whose characteristics differed significantly from Australopithecus africanus . Paranthropus robustus and Paranthropus boisei are therefore more closely related than to Paranthropus aethiopicus .

species

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

From when to when a fossil species existed can usually only be determined approximately. On the one hand, the fossil record is incomplete: there are usually only very few specimen copies for a fossil species. On the other hand, the dating methods indicate a certain age, but with considerable inaccuracy ; this inaccuracy then forms the outer limits for the "from ... to" information for lifetimes. All published age information is therefore provisional, which may also have to be revised after further specimen copies have been found.

In 1949 Robert Broom assigned the first hominine find from Swartkrans to the newly introduced species Paranthropus crassidens ; However, the Paranthropus fossils discovered there are now interpreted as Paranthropus robustus along with those from the Kromdraai site .

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 .

Some paleoanthropologists assign the species of the genus Paranthropus to the genus Australopithecus and then logically refer to them as Australopithecus aethiopicus , Australopithecus boisei and Australopithecus robustus .

In 1954 it was also proposed - without success - to rename the species Meganthropus palaeojavanicus , which is only described in Asia , to Paranthropus palaeojavanicus .

See also

literature

Web links

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

Individual evidence

  1. ^ Robert Broom : The Pleistocene Anthropoid Apes of South Africa. In: Nature . Volume 142, No. 3591, 1938, pp. 377–379, doi: 10.1038 / 142377a0 , full text (PDF)
  2. ^ The Cambridge Encyclopedia of Human Evolution. Cambridge University Press, 1992, p. 236.
  3. Thure E. Cerling et al .: Diet of Paranthropus boisei in the early Pleistocene of East Africa. In: PNAS . Volume 108, No. 23, 2011, pp. 9337-9341, doi: 10.1073 / pnas.1104627108
  4. ^ Faysal Bibi et al .: Ecological change in the lower Omo Valley around 2.8 Ma. In: Biology Letters. 9, 2013, p. 20120890, doi : 10.1098 / rsbl.2012.0890 .
  5. Brian A. Villmoare and William H. Kimbel: CT-based study of internal structure of the anterior pillar in extinct hominins and its implications for the phylogeny of robust Australopithecus. In: PNAS. Volume 108, No. 39, 2011, pp. 16200–16205, doi: 10.1073 / pnas.1105844108 , full text (PDF; 509 kB)
  6. ^ Robert Broom: Another new type of fossil ape-man. In: Nature. Volume 163, 1949, p. 57, doi: 10.1038 / 163057a0 .
  7. 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 )
  8. ^ John T. Robinson: The genera and species of the Australopithecinae. In: American Journal of Physical Anthropology. Volume 12, No. 2, 1954, pp. 181-200 (here: 196), doi: 10.1002 / ajpa.1330120216 .