Early humans

• • Sahelanthropus tchdenisis lived 7 mya in chad
  • Ardipithecus orrorin lived 6 mya - Kenya
  • Ardipithecus Kadabba lived 5.8-5.2 mya- Ethiopia Ardipithecus ramidus lived 4.8-4.2 mya -Ethiopia
• Hominins

  • more than human - extinct early ancestors humans
• Bipedalism

  • broad/wide pelvis- more muscle attchment + shorter ( ilium upper pelvis)
  • They walked on two feet - move on land
  • femur (thigh bone) slightly longer but mainly thicker - robust - beginning to angle because of hip bridge
  • more forward facing toes
  • big toe is more robust and slightly less abducted
  • Anteriorly positioned foremen magnum
  • more mobility in wrists- not good for tree climbing + instead good for manipulatin, holdin,carrying
  • foot getting more robust
  • extendible knees
• Evolving vs Extinction

  Evolving: species becomes new species with more desirable traits that is beneficial to their survival- driven by changes to environment

  Extinction: Species no longer exists because not able to adapt to changes in environment
• Arborealism

  • living moving in trees
  • curved digits and long arms/short legs
  • grasping big toe
  • prominent brow ridge
  • elongated/robust jaw
  • elevated shoulders
  • ridgid wrists and ankles
  • 4 toes spread out
  • angled pelvis
  • not good walkers flat feet, hunched because of foreman magnum
  • femur not angled
• Hominid- great apes

  • include extinct + modern hominins + chimp, gorillas, orangatanges
• Firsts

  • Kadabba - first non knuckle walker and fully extended knee - improved walking gait
  • Sahelanthropus- longest existing hominin/first bipedal facultative biped
  • Orrorin- hip bridge or scia notch/ strength for upright body weight
  • Ramidus : 4 forward facing toes - improved walking for pushing off
• General land descriptions

  • grasslands, thick forests, mixture of habitats, near Lakes, Mosaic, open Woodlands.
  • climate change - drier environment- Impacting vegetation- trees are being replaced by grasslands
• Skull/ brain trends

  • foramen magnum positioned more at the back of the skull
  • large brow ridge – protection
  • small skull vault - similar to chimps
  • robust jaw
  • flat/ slopes with projected jaw
• Trends with teeth + diet

  • thick enamel but thinning
  • plant based diet( nuts, fruit, leaves, branches, seeds, insect, etc.)
  • large molars flat for grinding
  • smaller canines
  • teeth similar to chimps
  • becoming smaller and no longer used for fighting more for showing dominance+ grasping/tear leaves
  • large projecting jaw extra jaw muscles from to sagittal creast