Geologic Time Scales
Dating from 65-1.8mya, the Tertiary Period saw the early mammals, flowers, insects, and birds move into the open niches left by the extinct dinosaurs. During this period, the major families of these groups evolved. The early primates appeared during this time, dividing into lineages that led to our present monkeys, apes, and man. The branch that led to Homo sapien separated from the branch the led to the modern chimpanzee some 6mya.