Ardipithecus kadabba

Ardipithecus kadabba
Temporal range: Late Miocene - Early Pliocene, 5.8–5.2 Ma
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Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Family: Hominidae
Subfamily: Homininae
Genus: Ardipithecus
White, 1994
Species: A. kadabba
Binomial name
Ardipithecus kadabba
Haile-Selassie, 2001

Ardipithecus kadabba is "known only from teeth and bits and pieces of skeletal bones".[1] The skeleton's remains were first dated to 5.8 to 5.2 million years ago, and later on from 5.77 to 5.54 million years.[2] According to the first description, these fossils are close to the common ancestor of chimps and humans. Their development lines are bimolecular estimates parted from 6.5 to 5.5 million years ago.[3]It has been described as a "probable chronospecies" (i.e. ancestor) of A. ramidus. Although originally considered a subspecies of A. ramidus, in 2004 anthropologists Yohannes Haile-Selassie, Gen Suwa, and Tim D. White published an article elevating A. kadabba to species level on the basis of newly discovered teeth from Ethiopia. These teeth show "primitive morphology and wear pattern" which demonstrate that A. kadabba is a distinct species from A. ramidus.[4]

The specific name comes from the Afar word for "basal family ancestor".[5]

Name

The name of the genus, Ardipithecus, is partly derived from the Afar language (of "ardi" = soil), partly from the Greek (from "πίθηκος", ancient Greek pronounced "píthēkos" = monkey). The epithet kadabba comes from the Afar language and refers to the father of a family. Ardipithecus kadabba accordingly means mutatis mutandis "progenitor of the ground ape".

Habitat

According to the first description it's suggested that, paleontological accompanying finds that Ardipithecus kadabba lived in a habitat that consisted of forests, wooded savannas and open water areas, as has been described for Sahelanthropus.[6]

Specimen

Type specimen is a right mandibular fragment with a resulting molar (M3) and five tooth or root fragments with the inventory number ALA-VP-2/10. The first description was in 2001, also relies on other bone finds which have been since 1992 to a total of five sites in the Afar Depression, Ethiopia excavated, and are from ten other individuals. In the first description by Yohannes Haile-Selassie, Ardipithecus kadabba was however recognized as a subspecies of Ardipithecus ramidus and Ardipithecus been termed "kadabba". Only in 2004 this designation has been in a joint publication of Haile-Selassie and the discovery of Ardipithecus, Tim White, revised.[3]

This correction of the initial allocation of the fossil record has been arguing that Ardipithecus kadabba "primitive" features having as the kind of Ardipithecus fossils assigned. Ardipithecus kadabba show thus also a greater similarity with the genera Sahelanthropus and Orrorin. Based on these statements were more bone finds that came to light in November 2002 and have been dated at 5.8 to 5.6 million years.

At the same time it was emphasized that no evidence could be found on the so-called Honing, so to cut traces on the teeth, as they are known by all older finds. They arise when the canines when biting rub against each other and so their peak constantly sharpen. To perform this "Honing", has the teeth adjacent to each canine a gap (diastema), in which the canine of the antagonistic jaw fits into it. The loss of this feature is used as an argument for the allocation of discoveries at that line of development of great apes, which led to the australopithecines to the genus Homo, and finally later.

Finally, it was noted in the same publication that Ardipithecus, Sahelanthropus and Orrorin belong to the same circle and shape - after finding other finds - could potentially be associated with a single genus. 2008 Bernard Wood and Nicholas Lonerga pointed out that other types of Hominini substantially different features of the dentition of Ardipithecus kadabba whose assignment to the Hominini than less can appear well justified, as this is the case in Ardipithecus.[7]

See also

References

  1. ↑ Gibbons, Ann (2009). "A New Kind of Ancestor: Ardipithecus Unveiled". Science 326 (5949): 36–40. Bibcode:2009Sci...326...36G. doi:10.1126/science.326_36. PMID 19797636.
  2. ↑ Webseite von Yohannes Haile-Selassie
  3. 1 2 Yohannes Haile-Selassie: Late Miocene hominids from the Middle Awash, Ethiopia.
  4. ↑ Haile-Selassie, Yohannes; Suwa, Gen; White, Tim D. (2004). "Late Miocene Teeth from Middle Awash, Ethiopia, and Early Hominid Dental Evolution". Science 303 (5663): 1503–1505. Bibcode:2004Sci...303.1503H. doi:10.1126/science.1092978. PMID 15001775.
  5. ↑ Ellis, Richard (2004). No Turning Back: The Life and Death of Animal Species. New York: Harper Perennial. p. 92. ISBN 0-06-055804-0.
  6. ↑ Giday WoldeGabriel et al.: Geology and palaeontology of the Late Miocene Middle Awash valley, Afar rift, Ethiopia.
  7. ↑ Bernard Wood, Nicholas Lonergan: The hominin fossil record: taxa, grades and clades.

External links

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