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Australopithecus Research Paper

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The Australopithecus afarensis was a robust, early australopithecine that lived 3 to 3.6 million years ago (McFarland). The origin of this species name comes from two different factors. The first comes from the genus name, Australopithecus. This genus means “southern ape” and was originally developed for a species found in South Africa. The word afarensis is based on the location where some of the first fossils for this species were first discovered (Dorey). “Lucy” was an Au. afarensis that was discovered in Afar, Ethiopia 3.2 million years ago and “Dikika Child” was of the same species that was discovered in Dikika, Ethiopia 3.3 million years ago. Because to these discoveries, the Au. afarensis is one our best known ancestors due to Lucy’s …show more content…

First, the broad cheek bones and broad skull are consistent of those of a robust australopithecine (McFarland). Whereas gracile australopithecines and Homo erectus species have a skinnier face and not as prominent check bones. Also, robust also have a small brain size resulting in less cranial capacity than the others. The second factor I considered was the sagittal crest that appeared to be on top of fossil #9’s cranium. For robust australopithecines, the sagittal crest is a bony ridge on top of the skull located more towards the back. (Dorey) The other crania at the station were missing this key feature which made them easy to eliminate. The third element I was looking for during my observation was the prognathism of the face, meaning the face was projecting forward (McFarland). This helped me eliminate the fossils I was unsure about. For example, fossil #8 had robust facial features like a prominent brow ridge but lacked the prognathic face robust australopithecines …show more content…

Like I stated before regarding the cranium of the Au. afarensis, they have a sagittal crest. The sagittal crest offers a dock for large chewing muscles in the primate. This has evolved due to the tough materials that the hominins needed to chew through and the stress that it placed on the skull while eating. This is also a factor for why robust australopithecines have huge cheek bones. This is why in the later evolved gracile australopithecines you see the reduction of a sagittal crest.

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