Paranthropus boisei

from Wikipedia, the free encyclopedia
Paranthropus boisei
Replica of the skull OH 5 and a lower jaw

Replica of the skull OH 5 and a lower jaw

Temporal occurrence
Upper Pliocene to Pleistocene
2.3 to 1.4 million years
Locations
Systematics
Human (Hominoidea)
Apes (Hominidae)
Homininae
Hominini
Paranthropus
Paranthropus boisei
Scientific name
Paranthropus boisei
Mary Leakey , 1959

Paranthropus boisei is a species of the extinct genus Paranthropus from the line of development of the hominini , whichoccurredin East Africa around two million years ago. Due to the very large molars and the also very large bone ridges on the skull, to which strong chewing muscles attached during life, the species is colloquially - but misleadingly - also referred to as "nutcracker man". The discoverer of the first finds of Paranthropus boisei , Mary Leakey , initially named the species Zinjanthropus boisei .

The delimitation of the genus Paranthropus from Australopithecus is controversial. The fossils are therefore also referred to as Australopithecus boisei by some researchers . The species of the genus Paranthropus are included in the Australopithecina group and probably represent an evolutionary sideline to the genus Homo .

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 boisei refers to Charles Boise, who had financially supported the Leakey excavations since 1948. Paranthropus boisei thus means "Boisescher neighbor", in the sense of "arranged in the family tree next to the genus of humans".

“ Zinjanthropus ” was derived from “Zinj”, the old local name for East Africa (see Zanj ).

Initial description

The holotype of Paranthropus boisei is an almost completely preserved skull known as OH 5 ( Olduvai Hominid 5 ) with complete dentition of the upper jaw . These fossils were discovered on July 17, 1959 at a location designated FLK I in the Olduvai Gorge by Mary Leakey , the wife of Louis Leakey . As early as August 15, 1959, the first description of the species Zinjanthropus boisei, introduced on the basis of the find, appeared in the journal Nature .

The skull OH 5 (also called "Zinji") was shown in the first description as male and so young that the rear molars - the M3 molars - did not yet show any signs of wear. It was also mentioned that OH 5 resembles Paranthropus ; However, around 20 features differing from Paranthropus were derived from its reconstruction , which seemed to justify an assignment to a new species.

A more detailed description of the holotype was not given until 1967 by Phillip Tobias .

OH 5 was the first, almost completely preserved skull of an adult individual from the Australopithecina group that was recovered in East Africa . His discovery resulted in a significant increase in funding for research projects in the region and, in particular, funding for Louis and Mary Leakey in the Olduvai Gorge. A direct consequence of this was the discovery of the fossil OH 7 in the fall of 1960, a completely preserved, dentate lower jaw, which in 1964 - after further finds - was determined to be the holotype of the newly introduced species Homo habilis . The Leakeys' discoveries also meant that other researchers began to explore sites such as Omo , Koobi Fora , Hadar and Laetoli from the 1960s onwards .

Dating

Paranthropus boisei are attributed to fossils from several sites and of different ages using radiometric dating or paleomagnetic analyzes . For finds from Koobi Fora ( Kenya ) an age of 1.9 to 1.49 million years was determined; Finds from Konso ( Ethiopia ) are a little younger at 1.43 to 1.41 million years. Finds from the Shungura formation in Ethiopia are much older , they are considered to be 2.3 to 2.1 million years old. The age of 1.77 million years was determined for the skull KNM-WT 17400 from the west bank of Lake Turkana ; The holotype, OH 5, has been dated to be 1.75 million years old.

features

Reconstruction
of Paranthropus boisei
in the Westphalian Museum of Archeology

A relatively large number of fossils of Paranthropus boisei have come down to us, including several skulls , various well-preserved skullcaps, lower jaws and teeth. The finds vary in size, which justifies the assumption that the species exhibited a pronounced sexual dimorphism . For the size of the brain, after measuring six skulls, 475 to 545 cm³ was calculated, which is approximately 100 cm³ larger than the brain volume of a modern chimpanzee .

Paranthropus boisei was assigned a weight of 40 to 80 kg and a height of 1.20 to 1.40 m; However, it is uncertain whether the bone finds from the area below the head that were used for this actually belong to Paranthropus boisei (they come from the same ancient layers) or to Homo habilis . Paranthropus boisei is similar to that by finds in South Africa occupied Paranthropus robustus , but the width of the face, most approaches for neck and jaw muscles and molars are made stronger. Paranthropus boisei had the largest molars and the highest biting force of all hominids and is therefore - as we now know: misleading - also called "nutcracker man"; however, its incisors and canines were comparatively small. With his powerful chewing muscles, which attached to massive jawbones and a conspicuously protruding bone ridge in the middle of the skull , he was able to chop up large amounts of hard plant food, such as dry grass.

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

The only shoulder blade attributed to the species is around 1.52 million years old and has echoes of a - earlier - suspensory locomotion ("rocking swing").

Because of the strong dentition, it counts - with Paranthropus robustus and Paranthropus aethiopicus - to the "robust" Australopithecines . Some experts regard Paranthropus boisei and Paranthropus robustus as regional variants of the same species: the finds of Paranthropus boisei come from areas north of the tropical rainforests , the finds of Paranthropus robustus from areas south of them. According to the current state of research, Paranthropus boisei and Paranthropus robustus are the last "robust" representatives of the australopithecines and died out without leaving any other species.

The most recent find to date related to Paranthropus boisei (and thus also the latest evidence for the genus Paranthropus ) is a 1.4 million year old skull from the Konso site in Ethiopia.

nutrition

A study published in 2011 came to the result that Paranthropus boisei from East Africa converted about 77 ± 7% more C 4 plants in its metabolism than all hominins examined so far and was therefore specialized in steppe grasses. A similar specialization in grasses and grass seeds show among the primates only some baboon species that have a similar set of teeth. A study of one-year-old steppe baboons ( Papio cynocephalus ), which feed primarily on the tuberous runners ( stolons ) of the tiger nuts ( Cyperus esculentus ) and, because they are still in the growth phase, require a higher food supply than adult steppe baboons, showed that Paranthropus boisei is could possibly have fed similarly; According to an estimate, he could have collected and eaten 80% of his daily energy requirement of 2500 kcal in three hours. The noticeably large teeth are therefore probably not the result of a diet that specializes in extremely hard food.

To Paranthropus boisei Asked fossil teeth from further south sites on Lake Malawi showed in 2018, however, that Paranthropus boisei there - like the equally old Homo rudolfensis from near helegenen localities - total about 60 to 70 percent of C 3 plants fed. “These were probably mainly parts of trees, for example their fruits, leaves and tubers. Considerably fewer plant components were consumed, which today dominate the open African savannahs. "

See also

Colored flags mark the locations of hominine fossils. "Zinji" was also discovered in this area.
Memorial plaque at the site of OH 5

Web links

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

Individual evidence

  1. ^ A b c Gary J. Sawyer, Viktor Deak: The long way to people. Life pictures from 7 million years of evolution. Spektrum Akademischer Verlag, Heidelberg, 2008, pp. 95–96
  2. ↑ Louis Leakey: A new fossil skull from Olduvai . In: Nature , Volume 184, No. 4685, 1959, pp. 491–493, doi: 10.1038 / 184491a0 , full text (PDF; 413 kB)
  3. ↑ Phillip Tobias: The Cranium and Maxillary Dentition of Australopithecus (Zinjanthropus) boisei. In: Olduvai Gorge, Volume 2. Cambridge University Press, Cambridge 1967
  4. ^ W. Eric Meikle, Sue Taylor Parker: Naming our Ancestors. An Anthology of Hominid Taxonomy. Waveland Press, Prospect Heights (Illinois) 1994, ISBN 0-88133-799-4 , pp. 85-86.
  5. ^ A b Bernard Wood , Nicholas Lonergan: The hominin fossil record: taxa, grades and clades. In: Journal of Anatomy . Volume 212, No. 4, 2008, p. 360, doi: 10.1111 / j.1469-7580.2008.00871.x , full text (PDF; 292 kB) ( Memento from October 29, 2013 in the Internet Archive )
  6. ^ The Cambridge Encyclopedia of Human Evolution. Cambridge University Press, 1992, p. 236
  7. ↑ a b 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
  8. ↑ David J. Green et al .: Scapular anatomy of Paranthropus boisei from Ileret, Kenya. In: Journal of Human Evolution. Volume 125, 2018, pp. 181–192, doi: 10.1016 / j.jhevol.2017.06.013
  9. ^ Gen Suwa, Berhane Asfaw, Yonas Beyene, Tim D. White et al .: The first skull of Australopithecus boisei. In: Nature. Volume 389, 1997, pp. 489-492, doi: 10.1038 / 39037
  10. ↑ Nutcracker man didn't crack nuts. Der Standard, May 2, 2011, accessed May 3, 2011 .
  11. ^ Charles Q. Choi: Ancient 'Nutcracker Man' ate more like a cow, it seems. MSNBC, May 2, 2011, accessed May 3, 2011 .
  12. ^ Gabriele A. Macho: Baboon Feeding Ecology Informs the Dietary Niche of Paranthropus boisei. In: PLoS ONE. Volume 9, No. 1: e84942, doi: 10.1371 / journal.pone.0084942
  13. ^ Peter S. Ungar, Frederick E. Grine, and Mark F. Teaford: Dental Microwear and Diet of the Plio-Pleistocene Hominin Paranthropus boisei. In: PLoS ONE. 3 (4): e2044; doi: 10.1371 / journal.pone.0002044
  14. ^ Ottmar Kullmer et al .: The first Paranthropus from the Malawi Rift. In: Journal of Human Evolution. Volume 37, No. 1, 1999, pp. 121-127, doi: 10.1006 / jhev.1999.0308 , full text
  15. ↑ Tina Lüdecke, Ottmar Kullmer, Ulrike Wacker, Oliver Sandrock, Jens Fiebig, Friedemann Schrenk and Andreas Mulch: Dietary versatility of Early Pleistocene hominins. In: PNAS. Volume 115, No. 52, 2018, pp. 13330-13335, doi: 10.1073 / pnas.1809439115
  16. ↑ You are what you eat: Early prehistoric humans had an extremely flexible diet. On: idw-online.de from December 13, 2018