Fossils suggest early primates inhabited a once-swampy Arctic

Fossils suggest early primates inhabited a once-swampy Arctic ...

Most primates inhabit the Arctic today. However, a series of fossils discovered since the 1970s demonstrate that this wasn't always the case.

Researchers claim that dozens of fossilized teeth and jaw bones discovered in northern Canada belong to two primitive primates — or at least close relatives — that lived in the Arctic around 52 million years ago. These are the first primate-like fossils ever discovered in the Arctic and reveal a groundhog-sized animal that might have skittered across trees above the Arctic Circle.

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The Arctic was significantly warmer during that time. However, animals still had to adapt to harsh winter months without sunlight. These difficulties render the presence of primate-like animals in the Arctic "incredibly strange," according to coauthor Chris Beard, a paleontologist at the University of Kansas in Lawrence.

Living in the modern Arctic is difficult due to extreme temperatures, poor plant growth, and constant darkness (SN: 6/5/13). Most primates, including humans, evolved from tiny tree-dwelling creatures that mainly ate fruit (SN: 6/5/13).

During the early Eocene Epoch, which began around 56 million years ago, the planet underwent a period of rapid warming that enabled forests and their warm-loving inhabitants to expand northward (SN: 11/3/15).

In part because of decades of paleontological research on Ellesmere Island in northern Canada, which revealed that the area once was dominated by swamps similar to those found in the southeastern United States today. This ancient, warm, wet Arctic environment was home to a wide variety of heat-loving animals, including giant tapirs and crocodile relatives.

Beard and his colleagues examined dozens of teeth and jawbone fossils found in the area, confirming that they belong to two species, Ignacius mckennai and Ignacius dawsonae. These two species were likely to migrate north as the planet warms up near the poles.

Scientists have long debated whether or not this lineage can be considered true primates or whether or not they were simply close relatives. Regardless, it's still "really weird and unexpected" to discover primates or their relatives in the area, according to Mary Silcox, a vertebrate paleontologist at the University of Toronto Scarborough.

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

The Arctic Ignacius had unusually strong jaws and teeth suitable for eating hard foods, according to the researchers, which may have assisted early primates in surviving winter fruits.

This research can reveal how animals can adapt to harsh environments. “Ellesmere Island is perhaps the finest deep time analog for a mild, ice-free Arctic,” says Jaelyn Eberle, a vertebrate paleontologist at the University of Colorado Boulder.

Beard believes that studying how plants and animals adapted to this remarkable period in Arctic history might provide clues for future residents of the Arctic.

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