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K-T boundary
Primateorigin
Primate Origins
• Challenge is to minimize speculation on things that do not fossilize.
• We live in the Cenozoic Era (past 65 m.y.)• Earliest primate fossils date from c. 63 mya;
Eocene Epoch• Originated from primate-like mammals
An EoceneAn Eocenemammalmammal
An EoceneAn Eoceneprimateprimate
Post-orbitalPost-orbitalbarbar
Anthropoid Origins
Aegyptopithecus Aegyptopithecus Basal to the ape-Basal to the ape-Old World monkeyOld World monkeyseparation ca.separation ca.33 mya33 mya
A transitional? group
• Genus Proconsul• Many species• Mixture of monkey-like
and ape-like characteristics
• 23 mya• Africa
*
* the only extant tailless monkey is the‘Barbary Ape.’
East Africa, Rift Valley systemmajor hominid sites
Adjusting branch-points anongoing process
e.g., fossil dated at 6-7 mya
Rocky Mountain News - July 11, 2002
Rocky Mountain News - July 11, 2002
Sahelanthropustchadensis
Early Hominids
• Ardipithecus ramidus (5.8 mya)• Australopithecus anamensis (4.2 mya)
– basal to other australopithecines)– definitive evidence of bipedalism.
• Derivative australopithecines divided into “gracile” and “robust” species groups
Genetic evidencefor split
Australopithecus afarensis“Lucy” (Hadar, Ethiopia)
3.8 mya
Australopithecusafarensis?
Why?
Australopithecus afarensis(Hadar, Ethiopia). Most complete skull found to date
Prognathism
Australopithecus afarensis
= Diastema
Parallel Parallel or slightlyconvergent
DivergentC-shape
Dental arcade
Australopithecus afarensis to A. africanus
“Taung child”
Australopithecusafricanus1925South Africa
Age at death?
