The fossil of a 21 million-year-old monkey was found in Las Cascadas formation in the Panama Canal Basin. The remains could help scientists understand how they managed to get to North America and where they migrated from.

Jonathan I. Bloch led a team that tackled the issue, they analyzed the fossil and the geological history from the American continent and published the results in the Journal Nature on April 20, 2016.

Scientists found a 21-million-year old monkey fossil in Panama. Credit: Hollywood Animals

The puzzle

The American continent is divided into 3 sections that form a whole; North, Central, and South America. However, this was not always the case. In the past, these parts were separated from each other and they all had their own flora and fauna. When these parts mixed, a boom in life diversity occurred as many of these species crossbred.

Until now, scientists had only found primate fossils in South America which scholars think came from Africa, but that’s another story. There was a remnant from a monkey called Isthmus of Panama. The creature started to appear 3 to 4 million years ago in North America, but the lack of similar findings in Central America puzzled the researchers.

These questions might have been partially answered by the new finding which consists of seven little teeth. They belong to a modern capuchins ancestor and the team estimates the teeth are 20.9 million years old. They also said that similar remains had been found earlier in South America.

New world monkeys are separated into 5 families that are classified as Platyrrhini or flat-nosed. The Ceboidea superfamily is the only survivor from the 5 and scientists around the world agree that they first appeared 22 to 25 million years ago. These species are succeeding apes and simians.

“This discovery suggests that family-level diversification of extant New World monkeys occurred in the tropics, with new divergence estimates for Cebidae between 22 and 25 Ma, and provides the oldest fossil evidence for mammalian interchange between South and North America,” said Joanathan Ivan Bloch Ph. D (University of Michigan) who is a specialist in Paleontology, Evolutionary Biology and Biological Anthropology with the University of Florida.

He also is the main author of the study.

The implications

The age of the fossil coincides with “recent” tectonic reconstruction that occurred in the early Miocene. However, the North and South American blocks of the continent were separated by 100 miles of sea at that moment, which would make for a very long and difficult swim. In this regard, the study researchers say the most probable scenario is that the monkeys rafted by accident in natural debris and were taken to modern Panama.

So far, the history of these creatures in the American continent is foggy. Scientists around the world agree that they first arrived in South America from Africa and then moved up, but they don’t have a clear idea on how they did it. Throwing some light in the matter, the new fossil makes the authors of the study think the place where the species mixed and started their colonization of the continent, was the tropics.

Source: Nature