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Au. garhi butchered animals about 2.5Ma and had humanlike leg proportions. Early stone tools were utilized by this hominin to slice meat from dead animals and smash its bones to get to the bone marrow inside. Although this early hominin had a cranial capacity of only 450 cc, changes to Au. garhi's diet lead to rapid growth of its brain which resembled the human brain. Additionally, Au. garhi's protruding jaw flattened out over time due to the change in diet. Au. garhi had a well mix of robust and humanlike features that often lead to researchers being confused on the possible lineage to the genus Homo. It is believed that this mixture of features was cause by climate change. Au. garhi also showed a weak connection between its dentition and the dentition of the Homo genus. It resembled early hominin of the genus Homo but was found to have even larger molars than Au. robustus. Au. Garhi’s second molar is 17.7 millimeters across. Additionally, in 1996 it was discovered that Au. garhi’s had a relatively long femur like humans, but also long arms like those of apes and early australopithecines. Anthropologist Owen Lovejoy who teaches at Kent State University in Ohio states that the reason of this morphology is that “the fossils show that human proportions evolved in steps, with the legs lengthening before the forearms shortened.”[1] Although classified as an Australopithecus, Au. garhi differs from Au. afarensis “by its absolutely larger postcanine dentition and an upper third premolar morphology with reduced mesiobuccal enamel line projection and less occlusal asymmetry.” [2]Australopithecus garhi also does not display the dental, cranial, and facial features of those common between A. aethiopicus, A. robustus, and A. boisei. Due to these differences, there is a controversial taxonomic discussion on whether or not Au. garhi should be categorized under the genus Homo or if it should be kept under Australopithecines. Its small cranial capacity resembles Australopithecines such as boisei and afarensis, but its meat eating habits as well as its bipedal locomotion signal it to be more of a hominin from the genus Homo. However, the hypothesis of the specimen BOU-VP-12/130, or Au. garhi, being ancestral to the genus Homo has been tested through cladistical analysis and has proven that Au. garhi is not a direct ancestor of the Homo- genus until now.[3]  

  1. ^ Culotta, Elizabeth (1999). "A New Human Ancestor?". Science. 284 (5414): 572–573. ISSN 0036-8075.
  2. ^ Asfaw, Berhane; White, Tim; Lovejoy, Owen; Latimer, Bruce; Simpson, Scott; Suwa, Gen (1999-04-23). "Australopithecus garhi: A New Species of Early Hominid from Ethiopia". Science. 284 (5414): 629–635. doi:10.1126/science.284.5414.629. ISSN 0036-8075. PMID 10213683.
  3. ^ Strait, David S.; Grine, Frederick E. (2019-05-31). "The systematics of Australopithecus garhi". Ludus Vitalis. 9 (15): 109–135. ISSN 1133-5165.