1. The Early Primate Fossil Record and the Origins of the Hominins
Chapter 12

2. Early Primate Evolution
The earliest mammals evolved during the Mesozoic era (252 to 66 mya)
At the end, great forests evolved with flowering trees that would later provide protection and food for early primates
The beginning of the Cenozoic era (65 mya to present)
Paleocene epoch (66 to 56 mya)
The dinosaurs and many other forms of life were extinct and mammals began their adaptive radiation
Eocene epoch (56 to 33 mya)
Most of the modern orders of mammals had appeared
More than 200 species are known

3. The Plesiadapiformes Possibly the earliest primates
Small, arboreal quadrupeds
Placental mammals
Long snout, small brain, and claws, and lack both a postorbital bar and a grasping big toe.
Many primatologists believe the plesiadapiformes were not direct ancestors of later primates
Two genera of plesiadapiformes are Purgatorius and Plesiadapis

4. The Eocene Primates Two groups of early primates
Display distinctive primate features
Wide geographical distribution
Extinction for most by the end of the Eocene
Adapidae
Resemble the modern lemurs and lorises
Date back as far as 47 mya
Darwinius masillae from Germany
Omomyidae
Resemble the living tarsiers
Found on all non-arctic continents

5. Anthropoid Evolution The Oligocene epoch (33 to 23 mya)
Early Oligocene
First anthropoids arose in Africa and Asia
The suborder Anthropoidea includes the living monkeys, apes and humans
End of the Oligocene
South America and Africa are totally split
Monkeys may have reached South America by “rafting”
Ancestry of New and Old World monkeys separate after 35 mya

6. Fayum Fayum of Egypt The Parapithecidae
The Late Eocene and Early Oligocene
Primates families Parapithecidae and Propliopithecidae
The Parapithecidae
Apidium
Small, squirrel-like
Fruit and seed eating
Clinging and leaping
Aegyptopithecus
Largest of Fayum anthropoids(13-18 lbs)
Short-limbed, slow-moving
Bridges the gap between Eocene fossils and succeeding Miocene (23 to 5 mya) hominoids
May represent a group of primates ancestral to both the cercopithecoids and the hominoids

7. New World Monkeys
Probably derived from early African anthropoids that traveled across the Atlantic Ocean on natural raft
Earliest ceboids
Branisella
Late Oligocene (~26 mya) of present day Bolivia
Evolution of the ceboids into their present subfamilies took place by the Middle Miocene

8. Old World Monkeys
The cercopithecoids were relatively scarce in the Miocene
More common, especially in Africa, by the Pliocene epoch (5 to 2.5 mya)
Family Victoriapithecidae
Two genera: Prohylobates and Victoriapithecus
Divivded into he Cercopithecinae and the Colobinae by the end of the Miocene (5 mya)

9. Hominoidea
The earliest hominoids appear in the fossil record in the early Miocene fossil beds of east Africa and Saudi Arabia
Most disappeared by around 8 mya
Proconsul (23 to 25 mya) of Eastern Africa
Most successful of the early hominoids
Ape-like teeth with Monkey-like body
Possibly the last common ancestor of both the Old World Monkeys and Apes
Gigantopitechcus (9 mya to 100,000 ya) of East Asia
Largest primate to ever live
Lived for millions of years
Survived long enough to live alongside some of the genus Homo
Sasquatch?

10. More Miocene Hominids Pierolapithecus (13 mya) of Spain
Discovered in 2004
Possible last ancestor of all great apes, but perhaps not orangs
Sivapithecus (12 to 8.5 mya ) of India and Pakistan
Large varied group with three species
One is likely the ancestor of the modern orangutan
chimpanzee (l), Sivapithecus (m), and a modern orangutan (r)
Both Sivapithecus and the orangutan exhibit a dished face, broad cheekbones, and projecting upper jaw and incisors

11. Sahelanthropus tchadensis
Discovered in 2001 in modern-day Chad
Not East African Rift Valley
Dated to at least 6 mya
Small, chimp-sized braincase
Human-like, vertical face
Huge brow ridge
Foramen magnum
Suggests some bipedalism
Hominin status questioned
Lived very close to the human-chimp split

12. Orrorin tugenensis Discovered in 2001 Dated to 5.5 to 6 mya
Present day Kenya
Chimp-like creature with bipedal ability
Questionable hominin status
Lived before Ardipithecus
More accepted as “hominin”

13. Ardipithecus Dated to 4.5 mya Two Species
ramidus
kadabba
Pelvis shows derived characteristics
Imperfect capacity for bipedal locomotion
Transitional pelvis
Divergent big toe
Woodland environment