Question: what is the difference between new world monkeys and old world monkeys

title: New World monkey
text: About 40 million years ago , the Simiiformes infraorder split into the parvorders Platyrrhini ( New World monkeys -- in South America ) and Catarrhini ( apes and Old World monkeys -- in Africa ) . The individuals whose descendents would become Platyrrhini are currently conjectured to have migrated to South America either on a raft of vegetation or via a land bridge . There are two possible rafting routes , either across the Atlantic Ocean from Africa or across the Caribbean from North America ; however , there is no fossil record to support the hypothesis of a migration from North America . The land bridge hypothesis relies on the existence of Atlantic Ocean ridges and a fall in the sea level in the Oligocene . This would have either produced a single land bridge or a series of mid-Atlantic islands to act as stepping stones for the migration . The latter is now the favorite choice .