Fossils 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 from
Africa 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