ANTH 203 Lecture Notes - Lecture 14: Australopithecus Anamensis, Quadrupedalism, Brachiation
3 Jun 2012
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Document Summary
Last common ancestor of humans and apes will have only primitive characteristics. Chimp line must have evolved refinements over the past 5-7 million years. So it"s possible that the last common ancestor possessed some hominin traits. Include dental elements and a nearly complete but distorted skull. Molar enamel is thicker than the average ape, but not as thick as australophithecines (later hominins) Cranial base shape is much closer to later hominins. Brain size similar to a chimp (350 cm3) Similar nuchal crest are present in both apes and some early hominins. Lake-side forest grading to open grassland, then desert. Thicker enamel might be a local adaptation to the drier environment. Position of the foramen magnum is similar to female apes. Dental enamel thicker than apes with rounded wear on molars. The femoral neck is human in form (thicker on the top and bottom), rather than round like apes. Small body size differences between adult males and females.
