65,000,000 years ago
Through the Late Cretaceous and Cenozoic There Have Been Five
Major Stages in Primate Evolution:
1. First radiation in the Late Cretaceous (100-65 mya):
a. Initial radiation of primates from common ancestor
b. Slight divergence among primitive primates from insectivore
c. Tooth shape indicates broadening of the diet
1. Second radiation in the Paleocene (65-55 mya):
a. Emergence of lemur and tarsier-like forms.
b. Grasping hands. c. Nails instead of claws.
d. Vision begins to dominate over smell.
2. Third radiation in the Early or Mid-Eocene (55–45 mya):
a. Increased arboreal quadrupedalism.
b. Primitive higher primates appear.
c. Larger brain and increased reliance on vision.
3. Fourth radiation in Lat