of monkeylike primates
indicate that anthropoids
were already established in Africa and Asia
40 million years ago. Africa
and South America had already drifted apart, and it is not clear whether ancestors of the New World monkeys reached South America
by rafting on logs or other debris
or by migration southward from North America
What is certain is that New World monkeys and Old World monkeys have been evolving along seperate pathways for many million of years.
All New World monkeys are arboreal, have prehensile tails and nostrils that open to the sides.
See also: Old World monkeys