Relatives of cat-sized primates lived in the Arctic 52 million years ago

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An analysis of fossils found in Canada’s far north has revealed that two previously unknown species of ancient close primates lived above the Arctic Circle about 52 million years ago, according to new research.

A co-author of the study, Dr. Chris Bird, Distinguished Professor of Ecology and Evolutionary Biology at the University of Kansas and Distinguished Curator at the University’s Institute of Biological Diversity and Museum of Natural History.

The two sister species lived on what is now Ellesmere Island in northern Canada. They are the first known primates, or relatives of primates, who lived in latitudes north of the Arctic Circle, according to a study published Wednesday in the journal Nature. Plus one.

The two species are named Ignacius mck Chennai and Ignacius dawsonae.

“To get an idea of ​​what Ignacius looked like, imagine a cross between a lemur and a squirrel about half the size of a house cat,” said Bird. “Unlike living primates, Ignasius had eyes on the sides of its head (instead of facing forward like our heads) and it had claws on its fingers and toes instead of its nails.”

When the researchers analyzed the fossil fragments, the jawbones and teeth of Ignacius looked different from other ancient people who lived in the southern regions of North America.

said lead study author Christine Miller, a doctoral student at the University of Kansas Institute for Biodiversity and Museum of Natural History.

Arctic primatomorphans have evolved special features in their jaws and teeth to eat harder foods, such as nuts and seeds, in contrast to their preferred diet of ripe fruit. This physical adaptation was likely because for half the year, the species lived in the darkness of Arctic winter, when it was more difficult to find food.

“We think this is probably the biggest physical challenge to the paleoenvironment of these animals,” Beard said.

These findings can also be used to understand how animals adapt and evolve amid periods of climate change – as can species facing the human-led climate crisis today.

Researchers believe that Primatomorphans descended from an ancestral species that headed north From the southern regions of North America. Similar fossils have been found throughout Wyoming, Texas, Montana and Colorado, according to Miller.

“No close relative of primates has ever been found at such extreme latitudes,” Miller said. “They are commonly found around the equator in the tropics. I was able to do a phylogenetic analysis, which helped me understand how fossils from Ellesmere Island related to species found in mid-latitudes of North America.”

The common ancestor of the two Ignacius species likely arrived on Ellesmere Island about 51 million years ago, Baird said. At the time, it was a peninsula jutting into the Arctic Sea from neighboring parts of North America.

Ignasius McKennay and Ignasius Dawsoney are named in part after two of Byrd’s former colleagues and mentors, he explained: the late paleontologists Dr. Mary Dawson of the Carnegie Museum of Natural History in Pittsburgh and Dr. Malcolm McKenna of the American Museum of Natural History in New York, both of whom worked extensively on the island. Ellesmere.

During these ancient times, the Arctic Circle was a warmer and more hospitable place for life. Global warming has caused the region to be warmer and wetter, with a swampy environment. Warmer temperatures during this period likely encouraged Ignacius’ ancestors to venture north.

“Winter temperatures may have dropped to freezing for short periods of time, but we know there have never been any consistent freezing temperatures, because crocodilians have been found on Ellesmere Island, and they can’t tolerate prolonged freezing,” Beard said. . “In the summer, temperatures get to about 70 degrees Fahrenheit.”

Despite the warmer temperatures, primitive primates still had to adapt to survive in their unique northern ecosystem. They are outgrown from their southern squirrel-like relatives. Beard said such growth occurs most commonly in mammals that live in northern latitudes because it helps them maintain a required core body temperature.

“(The results) tell us to expect dramatic and dynamic changes in the Arctic ecosystem as it transforms in the face of continued warming,” Beard said. “Some animals that do not currently live in the Arctic will colonize that region, and some will adapt to their new environment in ways that parallel Ignacius. Likewise, we can expect some of the new colonizers to diversify in the Arctic, just as Ignacius did.”