For an interesting weekend read, from Popular Science: Why are there no native monkeys in North America?
“Primates came to the New World (meaning North and South America) from, we think, Africa. As improbable as it sounds, scientists think early primates crossed the Atlantic Ocean and landed on the shores of both continents tens of millions of years ago, probably on some kind of vegetation raft. That’s how most plants and animals get to isolated islands–which the Americas were, at the time. Fossils have been recovered of early primates in Texas a whopping 43 million years ago, the oldest primate fossil ever found in North America. But the continents looked very different then, compared to now; most importantly, North and South America were completely different islands. The Isthmus of Panama, which we now refer to as Central America, didn’t appear until much later, by which time the climate on both Americas was very different from when the primates first landed there.”






