Australopithecus garhi

Taxobox | name = "Australopithecus garhi"
fossil_range = Pliocene
regnum = Animalia
phylum = Chordata
classis = Mammalia
ordo = Primates
familia = Hominidae
genus = "Australopithecus"
species = "A. garhi"
binomial = †"Australopithecus garhi"
binomial_authority = Asfaw et al, 1997

"Australopithecus garhi" is a gracile australopithecine species whose fossils were discovered in 1996 by a research team led by Ethiopian paleontologist Berhane Asfaw and Tim White, an American paleontologist. The hominin remains were initially believed to be a human ancestor species and the final missing link between the "Australopithecus" genus and the human genus, "Homo". However it is now believed that "A. garhi", although more advanced than any other australopithecine, was only a competitor species to the species ancestral to "Homo" and therefore not a human ancestor. The remains are from the time when there are very few fossil records, between 2.0 and 3.0 million years ago. Tim White was the scientist to find the first of the key "A. garhi" fossils in 1996 near the village of Bouri, located in the Middle Awash of Ethiopia's Afar Depression. The species was confirmed and established as "A. garhi" on November 20 1997 by the Ethiopian paleoanthropologist Yohannes Haile-Selassie. The species epithet "garhi" means "surprise" in the local Afar language.

Morphology and interpretations

The traits of "A. garhi" fossils such as BOU-VP-12/130 are somewhat distinctive from traits typically seen in "Australopithecus afarensis" and "Australopithecus africanus". An example of the distinction can be seen when comparing the Hadar maxilla ("A. afarensis") to the Bouri specimen of "A. gahri". The cranial capacity of "A. garhi" measures 450cc, the same size as other australopithecines. The mandible classified as "Asfaw et al." has a morphology generally believed to be compatible with the same species, yet it is possible that another hominin species may have been found within the same deposits. Studies made on the premolars and molar teeth have a few similarities with those of "Paranthropus boisei" since they are larger than any other gracile form of australopithecine. It has been suggested that if "A. garhi" is ancestral to "Homo" (ie. "Homo habilis") the maxillary morphology would have undergone a rapid evolutionary change in roughly 200,000 and 300,000 years.

Earliest stone tools

Few primitive shaped stone tool artifacts closely resembling Olduwan technology were discovered with the "A. garhi" fossils, dating back roughly 2.5 and 2.6 million years old. The 23 April 1999 issue of "Science" mentions that the tools are older than those acquired by "Homo habilis", which is thought to be a possible direct descendant of more modern hominins. For a long time anthropologists assumed that only members of early genus "Homo" had the ability to produce sophisticated tools. However, the crude ancient tools lack several techniques that are generally seen in later forms Olduwan and Acheulean such as strong rock-outcroppings. In another site in Bouri, Ethiopia, roughly 3,000 stone artifacts had been found to be an estimated 2.5 million years old in age.

References

*http://home.hetnet.nl/mr_9/95/krocat/english/news/news9.htm
*http://home.austarnet.com.au/stear/cg_australopithecus_garhi.htm

ee also

* List of fossil sites "(with link directory)"
* List of hominina (hominid) fossils "(with images)"

External links

*http://www.scienceinafrica.co.za/2001/nov/ancestor.htm
*http://www.archaeologyinfo.com/australopithecusgarhi.htm
*http://cas.bellarmine.edu/tietjen/Human%20Nature%20S%201999/australopithecus_garhi.htm