ARCH 131 Lecture Notes - Lecture 6: Foramen Magnum, Thoracic Vertebrae, Femur Neck

• School: Simon Fraser University
• Department: Archaeology
• Course: ARCH 131
• Professor: Bess Doyle

Document Summary

These don"t all evolve at the same time. Proximal distal (base to end of limb) Weight transfer (each leg pushes off independently) Balance (how to keep it all stacked up!) Foramen magnum (hole for spinal cord) is directly underneath vs posterior. Muscle attachments more gracile (smoother), positioned underneath vs at back. A shorter more upright back is best for bipeds. Pelvis is round and wide dorsoventrally flattened & mediolaterally widened. Glutes attach posteriorly & laterally to act as stabilizers. In quadrupeds they attach posteriorly & act as propellors. Femur (thigh) slanted medially thanks to angling of femur neck and condyles. Tibia (shin) goes straight down from knee. Big, robust toe, aligned w/ others longitudinal arch. Divergence of hominine ancestors began between 10 8mya. Around 10mya, a new trait: the ability to catabolize ethanol. Stem hominins existed between 7 5mya. Humerus is close to arboreal ape"s shape. 5. 8 and 5. 2 mya, middle awash, ethiopia.