The Arctic Circle hasn’t always been so, well, Arctic. About 52 million years ago, at the beginning of the Eocene, it was still almost dark for half the year as it is today, but it was a little warmer, more humid. The Arctic of years past had a boreal forest ecosystem similar to what is seen in Canada and parts of Russia today. It was even home to many vertebrates from the early Cenozoic era, including ancient crocodiles and camels.

It was also home to at least two sister species of quasi-primates, Ignatius McKenna and I. dawsonae. Scientists have found new specimens that are the oldest near-primate remains that have been found north of the Arctic Circle to date. The specimens and what we might learn from them are described in a study published January 25 in the journal PLOS ONE.

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“No related primate has ever been found at such extreme latitudes,” said study co-author Kristen Miller, a doctoral student at the University of Washington’s Biodiversity Institute and Museum of Natural History. Kansas, in a statement. “They are more commonly found around the equator in tropical regions.”

A process called phylogenetic analysis, which uses branching diagrams to show a species’ evolutionary history and relationships, helped the team understand how the fossils of these newly discovered species related to those found in modern locations. northern mid-latitudes. America.

The specimens were found on Ellesmere Island in Nunavut, Canada, near the northwest coast of Greenland. They have been found in sediments that date back to the warmer Eocene, and studying this period could predict how Earth’s ecosystems will behave in years to come due to climate change.

According to Miller, both species are descended from a common northerly ancestor who possessed the spirit “to boldly go where no primate has gone before.”

The intense periods of darkness in the Arctic Circle may have caused these two species to develop a surprising trait compared to their other primate relatives: stronger teeth and jaws. The team believe it was much more difficult to find food during the dark winter months. Parents of arctic primates likely had to eat tougher, harder materials like nuts and seeds, as opposed to softer snacks like fruit, which could have impacted their unique dentistry.

“A lot of what we do in paleontology is looking at teeth — they preserve the best,” Miller said. “Their teeth are just super weird compared to their closest relatives. So what I’ve been doing for the past two years is trying to figure out what they were eating and if they were eating different foods than their mid-latitude counterparts.

[Related: There Used To Be Freaking Camels In The Arctic.]

The closest relatives of these species were probably a group of primates called plesiadapiforms, which were found further south during this time. The northern primates were larger than the southern ones, but all seem to be rodent-sized.

“Some mid-latitude plesiadapiforms in North America are really, really tiny,” Miller said. “Of course, none of these species are related to squirrels, but I think this is the closest creature we have that helps us visualize what they might have looked like. They were probably very arboreal, so alive in the trees most of the time.

The team believe that some of the adaptations that Arctic near-primate species have taken on during another period of global warming demonstrate how some animals might develop new traits – lessons that animals might experience as a result. of climate change today.

“I think what he’s saying is probably [that] The range of primates could expand with climate change or at least shift towards the poles rather than the equator,” Miller said. “Life is starting to get too hot there, maybe we’ll have a lot of taxa moving north and south, rather than the intense biodiversity we see at the equator today.”

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