The fossil of the earliest known primate to have inhabited the North American continent - Teilhardina magnoliana , dating 55 million years ago, was recently uncovered in the Gulf Coastal Plain of Mississippi, according to a study led by Christopher Beard, paleontologist at the Carnegie Museum of Natural History in Pittsburg, Pennsylvania.

Although it is believed that primates first appeared almost synchronously in Asia, Europe and North America, a correlation using the global carbon isotope excursion (CIE) indicated that the primates first migrated to North American before arriving to Europe from Asia.

The newly uncovered fossil is at least 100,000 years older than similar primates, such as Teilhardina brandti discovered in the Big Horn Basin of Wyoming or Teilhardina belgica discovered in Belgium, and dates back shortly after the Paleocene-Eocene period, when the earth was marked by a rapid and dramatic global warming phenomenon, known as Paleocene-Eocene Thermal Maximum - PETM.

This is presumably the reason why the small, one-ounce creature migrated from Asia to North America instead of Europe. The high temperatures on Earth’s surface, the melting of ice caps and the expansion of typical lush vegetation towards the North American continent, which was then connected to Asia through a landmass, determined Teilhardina to simply follow the line of vegetation.

The creatures continued to move towards the interior of the North American continent, as temperatures were cooler there, and later reached Europe, probably 10,000 – 20,000 years later, after the sea levels dropped significantly.

As Beard said in his study, “this primate is one component of the earliest Eocene Red Hot local fauna, which also includes sharks and rays, bony fishes, snakes, lizards, crocodilians, birds, and a variety of other mammals,” clearly suggesting that the primates lived in Mississippi when sea levels were high.

The tiny exemplary uncovered in the Gulf Coastal Plain of Mississippi presumably looked like the big-eyed tarsiers in Southeast Asia, they lived in trees and most probably ate fruits and insects. Its presence on the North American continent at that particular time can be explained through the muggy, hot environments the creature preferred.

Image credits: PNAS