Pre australopithecine 2-2
Chimps diverge 8 mya
Pre Australopithecines (7-4 mya)
Sahelanthropus tchadensis (7-6mya). - 2001. Michel Brunet. Djurab desert, chad. 2500km from East rift valley
350 cc brain.
foramen magnum backward
non honing complex.
forest habitatnear lake.
Orrorin tugensis 6mya. tugen hills. kenya. bipedal curved phalanx. non honing complex.
Ardipithecus Kadabba & Ar. ramidus. (6-4 mya)
Awash valley Ethiopia. Tim White found. 1980s. 70 scientists. continuous record of hominin evolution. Mosaic evolution features. ardi = groud & ramid = root.
Ardipithecus - complete skeletons found. Ecological details found. 4ft tall.
Lived in forest not grasslands.
Hominin masticatory conplex. Non projecting canines. Thicker enamel. Big toe opposable. Curved phlanges and rigid foot so poor bipedalism.
No suspension bone type in elbow. Evolved pelvis. Forearm extraordinary long.
longforearm than humans - primitive. pelvis developed. lower limbs have elongated divergent toe for grasping but also for bipedality. Mosaic evolution in ardipithecus.
Enamel thinner than man. big toe opposable - unlike man. phlanges curved to grasp. So part time quadruped & part time biped.
But had giving features and arboreal traits.