Monkeys from South American were long thought to have moved into the North America through the Isthmus of Panama about three and a half million years ago. However, new evidence suggests that these early primates migrated into the continent using makeshift rafts some 21 million years ago.
In a study featured in the journal Nature, researchers from the Florida Museum of Natural History (FLMNH) have identified the remains of an ancient species of monkey known as Panamacebus transitus, which was recovered during excavations for the Panama Canal.
Jonathan Bloch, a paleontologist from the FLMNH, explained that the Panamacebus transitus was a close relative of modern-day capuchin monkeys, or "organ-grinder" monkeys, and squirrel monkeys that are typically found in Central and South America.
An analysis of the prehistoric monkey's teeth revealed that they were encased in rocks that dated back to 21 million years ago. This suggests that the animal was somehow able to reach Panama from South America even before the two continents were connected with the formation of the Isthmus of Panama.
While the researchers were able to establish a connection between the Panamacebus transitus and present-day monkeys in South America, they are still unsure how these early monkeys managed to make it to North America without using a land bridge.
One theory Bloch considers is that these prehistoric creatures built mats using the local dirt and vegetation in South America. They then used these improvised rafts to cross the large body of water in order to reach Panama.
Ancient primates were known to use various materials in their surroundings to make makeshift floatation devices. Scientists believe early monkeys from Africa used this very same technique to cross the Atlantic Ocean and reach South America some 40 million years ago.
Bloch pointed out that there is also evidence that suggests the Panamacebus transitus found plants in the Panama that were similar to those located in South America. This allowed them to eat the same types of fruits that they were already used to.
Bloch added that the Panamacebus transitus chose not to venture further north because the vegetation in these areas, such as in Nicaragua and Costa Rica, were vastly different from what they were accustomed to.
He said that these forests would not have offered the types of food that these early monkeys needed to survive.
Photo: Carlos Luna | Flickr
