Australopithecus garhi

Australopithecus garhi is a gracile australopithecine species whose fossils were discovered in 1996 by a research team led by Ethiopian paleontologist Berhane Asfaw ad Tim White, an American paleontologist. The remains are believed to be a human ancestor species and most likely the direct ancestor to the human genus Homo.

Tim White was the scientist to find the first of the key A. garhi fossils in 1996 within the Bouri Formation found 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 handle “garhi” means “surprise” in the local Afar language.

The characteristics of A. garhi fossils such as BOU-VP-12/130 are rather distinctive from characteristics usually seen in Australopithecus afarensis and Australopithecus africanus.

The mandible classified as Asfaw et al. has a morphology usually believed to be compatible with the same species, yet it is possible that another hominin species might 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 proposed that if A. garhi are ancestors of Homo, the maxillary morphology would have undergone a rapid evolutionary change in about 200,000 and 300,000 years.

Not many primitive shaped stone tool artifacts closely resembling Olduwan technology were discovered with the A. garhi fossils, dating back about 2.5 and 2.6 millions years old. The tools are suggested to be older than those acquired by Homo habilis, which is thought to be a possible direct ancestor of more modern hominins. For quite some time anthropologists assumed that only members of early genus Homo had the ability to create sophisticated tools. However, the crude ancient tools lack several techniques that are usually seen in later forms Olduwan and Acheulean such as strong rock-outcroppings. In another site located in Bouri, Ethiopia, about 3.000 stone artifacts had been found to be an estimated 2.5 millions years old.

Image Caption: Australopithecus afarensis reconstruction. Displayed at Museum of Man, San Diego, California. Credit: Durova/Wikipedia (CC BY-SA 3.0)