Fossils suggest that the first primates in the Arctic were once swampy

Today, the Arctic is an inhospitable place for most primates. But a series of fossil finds since the 1970s suggest that this was not always the case.

Dozens of teeth and jawbones unearthed in northern Canada belonged to two species of primates, or at least relatives of primates, that lived in the Arctic for about 52 million years, researchers reported on January 25. PLOS FIRST. These remains are the first primate-like fossils ever found in the Arctic and indicate a land-sized animal that darts across the trees in the swamp that once existed above the Arctic Circle.

The Arctic was significantly warmer at that time. But the creatures still had to adapt to extreme conditions, such as the long winter months without the sun. These challenges make the presence of primate creatures in the Arctic “unbelievable,” says coauthor Chris Beard, a paleontologist at the University of Kansas in Lawrence. “No other primate or primate relative has been found this far north.”

Between the cold temperatures, limited plant growth and months of perpetual darkness, living in the modern arctic is not easy. This is especially true of primates, which evolved from small, tree-dwelling creatures that feed largely on fruit.SN: 6/5/13). To this day, most primates—with the exception of humans and a few other vagrants like the Japanese snow monkey—tend to stick to tropical and subtropical forests, found mostly around the equator.

But these forests were not always confined to the present place. During the early Eocene Epoch, which began about 56 million years ago, the planet underwent a period of intense warming, which allowed forests and their warmth-loving inhabitants to spread northward (SN: 11/3/15).

Scientists know about this arctic climate in part because of decades of paleontological work on Ellesmere Island in northern Canada. These excavations revealed an area once dominated by swamps not unlike those found in the southern United States today. This ancient, warm, humid, arctic environment was home to a wide array of heat-loving animals, including giant tapirs and their close relatives, crocodiles.

For the new study, Barbatus and colleagues examined dozens of teeth and jaw fossils in the area, concluding that they belonged to two species; Ignatius McKenna and Ignatius Dawson. These two species belonged to a now-extinct genus of small mammals that were widespread throughout the Eocene of North America. Arctic variants probably made their way north as the planet warmed, taking advantage of the opening of new habitat near the poles.

Scholars have long debated whether these lineages can be considered true primates or simply relatives. Still, it’s still “really weird and unexpected” to find primates or their relatives in the area, says Mary Silcox, a vertebrate paleontologist at the University of Toronto’s Scarborough.

One, Ellesmere Island was already north of the Arctic Circle 52 million years ago. So when conditions were warmer and wetter, the swamp was plunged into continuous darkness during the winter months.

he arrived recently Ignatius he had to adapt to these conditions. Unlike its southern, arctic cousin Ignatius Researchers have found that grins and teeth are usually the strongest for eating solid foods. Perhaps these ancient primates helped to feed on nuts and seeds during the winter, when fruit was not so affordable.

This research may shed light on how animals can adapt to extreme living conditions. “Ellesmere Island is an excellent high-time analog for the mild, ice-free Arctic,” says Jaelyn Eberle, a vertebrate paleontologist at the University of Colorado Boulder.

Investigating how plants and animals adapted to this significant period in Arctic history, Beard says, could offer clues to the future of Arctic populations.