- Australopithecus africanus
Taxobox | name = "Australopithecus africanus"
image_width = 250px
image_caption= Replica of the Mrs. Ples skull
genus = †"
species = †"A. africanus"
binomial = †"Australopithecus africanus"
binomial_authority = Dart, 1925
"Australopithecus africanus" was an early hominid, an
australopithecine, who lived between 2-3 million years ago in the Pliocene. [ [http://www.mnh.si.edu/anthro/humanorigins/ha/a_tree.html Human Ancestors Hall: Tree ] ] In common with the older " Australopithecus afarensis", "A. africanus" was slenderly built, or gracile, and was thought to have been a direct ancestor of modern humans. Fossilremains indicate that "A. africanus" was significantly more like modern humans than "A. afarensis", with a more human-like craniumpermitting a larger brainand more humanoid facial features. "A. africanus" has been found at only four sites in southern Africa - Taung (1924), Sterkfontein (1935), Makapansgat(1948) and Gladysvale (1992). [http://www.archaeologyinfo.com/australopithecusafricanus.htm Australopithecus africanus ] ]
Raymond Dartwas at Taungnear Kimberley, South Africain 1924 when one of his colleagues spotted a few bone fragments and the cranium on the desk of a lime worker. [ [http://www.press.uchicago.edu/Misc/Chicago/284158_brain.html Raymond Dart and our African origins ] ] The skull seemed like an odd apecreature sharing human traits such as eye orbits, teeth, and, most importantly, the hole at the base of the skull over the spinal column (the foramen magnum) indicating a human-like posture. Dart assigned the specimen the name "Australopithecus africanus" ("southern ape of Africa"). This was the first time the word "Australopithecus" was assigned to any hominid. Dart claimed that the skull must have been an intermediate species between ape and humans, but his claim about the Taung Childwas rejected by the scientific community at the time due to the belief that a large cranial capacity must precede bipedal locomotion, this was exacerbated by the widespread acceptance of the Piltdown Man. Sir Arthur Keith, a fellow anatomist and anthropologist, suggested that the skull belonged to a young ape, most likely from an infant gorilla.
Dart's theory was supported by
Robert Broom. [http://www.anth.ucsb.edu/faculty/walker/classes/anth121/121australopithecus.pdf Primate Origins ] ] In 1938 Broom classified an adult endocranial casthaving a brain capacity of 485 cc, which had been found by G. W. Barlow, as "Plesianthropus transvaalensis". On April 17, 1947, Broom and John T. Robinsondiscovered a skull belonging to a middle-aged female, [ [http://archaeology.about.com/od/rterms/g/robinsonjt.htm John T. Robinson ] ] Sts 5, while blasting at Sterkfontein. Broom classified it also as "Plesianthropus transvaalensis", and it was dubbed Mrs. Ples by the press (though the skull is now thought to have belonged to a young male). The lack of facial projection in comparison to apes was noted by Raymond Dart (including from Taung Child), a trait in common with more advanced hominines. Both fossils were later classified as "A. africanus".
Morphology and interpretations
Like "A. afarensis", "A. africanus" the
South Africancounterpart was generally similar in many traits, a bipedal hominidwith arms slightly larger than the legs (a physical trait also found in chimpanzees). Despite its slightly more human-like cranial features, seen for example in the craniums "Mr. Ples" and "Sts 71", other more primitive features including ape-like curved fingers for tree climbing are also present.
Due to other more primitive features visible on "A. africanus", some researchers believe the hominin, instead of being a direct ancestor of more modern hominins, evolved into "
Paranthropus". The one particular robust australopithecine seen as a descendent of "A. africanus" is " Paranthropus robustus". Both "P. robustus" and "A. africanus" craniums seem very alike despite the more heavily built features of "P. robustus" that are adaptations for heavy chewing like a gorilla. "A. africanus", on the other hand, had a cranium which quite closely resembled that of a chimp, yet both their brains measure about 400 cc to 500 cc and probably had an ape-like intelligence. "A. africanus" had a pelvis that was built for slightly better bipedalism than that of "A. afarensis". Charles Darwinsuggested that humans had originally evolved from Africa, but during the early 20th century most anthropologists and scientists supported the idea that Asiawas the best candidate for human origins. [ [http://www.sciencedaily.com/releases/2007/10/071025160653.htm New Ideas About Human Migration From Asia To Americas ] ] However, the famous Leakeyfamily have argued in favor of the African descent since most hominid discoveries such as the Laetolifootprints were uncovered in Eastern Africa. [ [http://www.apologeticspress.org/articles/127 Apologetics Press - Human Evolution and the “Record of the Rocks” ] ]
With regards to bipedalism
Recent evidence regarding modern human
sexual dimorphism(physical differences between men and women) in the lumbar spinehas been seen in pre-modern primates such as "A. africanus". This dimorphism has been seen as an evolutionary adaptation of females to better bear lumbar load during pregnancy, an adaptation that non-bipedal primates would not need to make. [The Independent's article [http://news.independent.co.uk/sci_tech/article3247561.ece A pregnant woman's spine is her flexible friend] , by Steve Connor from The Independent (Published: 13 December 2007) quoting [http://www.utexas.edu/cola/depts/anthropology/faculty/profiles/Shapiro/Liza/ Shapiro, Liza] , University of Texas at Austin Dept. of Anthropology about her article, Whitcome, et al., [http://www.nature.com/news/2007/071212/full/news.2007.374.html Nature advance online publication, doi:10.1038/nature06342 (2007)] . ] [ [http://news.nationalgeographic.com/news/2007/12/071212-pregnancy-tips_2.html Why Pregnant Women Don't Tip Over.] Amitabh Avasthi for National Geographic News, December 12, 2007. This article has good pictures explaining the differences between bipedal and non-bipedal pregnancy loads.]
List of human fossils
List of fossil sites"(with link directory)"
* List of hominina (hominid) fossils "(with images)"
* [http://www.mnsu.edu/emuseum/biology/humanevolution/africanus.html MNSU]
* [http://www.mnh.si.edu/anthro/humanorigins/ha/afri.html Smithsonian]
* [http://www.handprint.com/LS/ANC/evol.html Handprint]
* [http://www.maropeng.co.za Maropeng - The Cradle of Humankind] Official Website
* [http://whc.unesco.org/pg.cfm?cid=31&id_site=915 UNESCO - Fossil Hominid Sites of Sterkfontein, Swartkrans, Kromdraai, and Environs]
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Look at other dictionaries:
Australopithecus africanus — Original des Schädels eines A. africanus („Mrs. Ples“) im Transvaal Museum in Pretoria Zeitraum Pliozän 3,0 bis 2,5 Mio. Jahre … Deutsch Wikipedia
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Australopithecus africanus — Australopithecus africanus … Wikipédia en Français
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Australopithecus africanus — La historia de los Australopithecus Africanus como especie reconocida data de 1924 cuando fue descubierto por Raymond Dart en Taung, Sudáfrica, el cráneo de un niño de la especie Africanus de establecidos hasta esas fechas, debido a esto también… … Enciclopedia Universal
Australopithecus africanus — noun gracile hominid of southern Africa; from about 3 million years ago • Hypernyms: ↑australopithecine • Member Holonyms: ↑genus Australopithecus, ↑Australopithecus * * * /af ri kah neuhs, kan euhs/ 1. an extinct species of gracile hominid,… … Useful english dictionary
Australopithecus africanus — /af ri kah neuhs, kan euhs/ 1. an extinct species of gracile hominid, formerly known as Plesianthropus transvaalensis, that lived in southern Africa about three million years ago. 2. a fossil belonging to this species. See illus. under hominid.… … Universalium
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