This hominid existed in central Africa from 3.5 to 3 million years ago. It was discovered in the Bahr el Ghazal riverbed in Chad by Michael Brunet in 1993. The single piece of fossil evidence for this species is one partial mandible with dentition, so only very limited conclusions may be drawn as to physical traits.
Cranial capacity: assumed to be around 400 cc
Height: Based on the size of the mandible found, researchers speculate that this species was smaller than both Ardipithecus ramidus and Australopithecus anamensis
Characteristics
Bahrelghazali had a jaw and teeth similar to Australopithecus afarensis but with a more modern chin. The premolar enamel was thicker than that of Ardipithecus ramidus, but thin compared to other Australopithecines. The species had a modern molar coupled with the primitive three-root teeth typical of chimpanzees, as well as short pointed canines. The overall physical build is assumed to be similar to that of Afarensis.
Location, Location, Location
What makes this limited information so important is the area where the mandible was found. Before the discovery of Bahrelghazali, it had been believed by some scientists that the formation of the Great Rift Valley had facilitated the evolutionary separation of ape and man by dividing a single population into two groups that could no longer interbreed. Those on the east side would have evolved into Australopithecines and those on the west side would have evolved into modern apes. The fossil found in Chad implies that there were Australopithecines west of the Rift Valley. It may also suggest that these hominids were more mobile and versatile than was previously thought.
The find at Chad may also question the accepted views of how bipedalism became our ancestor’s main form of locomotion. The belief is widely held that shrinking forests and widening grasslands made walking upright important to survival because of the increased range of vision needed to detect predators and judge distances. However, if there were bipedal Australopithecines living in the still forested areas west of the Great Rift Valley, it would be necessary to formulate new theories.
New Species?
Not all researchers believe that Australopithecus bahrelghazali is a separate species from Australopithecus afarensis. The mandible shares many characteristics with that of Afarensis, and may simply be the result of the movement of one individual set of remains, and not indicative of a population located west of the Rift Valley. Nevertheless, the fossil found in Chad does raise interesting questions about the origin of our human ancestors. More fossil evidence in the same area will be needed to determine what exactly Bahrelghazali means to hominid evolution.
This information was unearthed from:
http://www.humboldt.edu/~mrc1/australo.shtml
http://www.msu.edu/~heslipst/contents/ANP440/bahrelghazali.htm
http://www.scienceinafrica.co.za/2001/nov/ancestor.htm
http://www.people.fas.harvard.edu/~witzel/mt26p.html
http://www2.mc.maricopa.edu/anthropology/hominid_journey/sorting_early.html