As ancient Arctic glaciers melt and retreat from their centuries old positions, the permafrost found near the poles is revealing secrets buried for thousands of years. Each new discovery is not only a portal to the past but a clue to the mystery of what life was like on Earth before people came along and got greedy.

Ancient humanoids had dogs living nearby.

Earlier this year, scientists thawed and performed an autopsy on a 12,400-year-old puppy uncovered in the Russian permafrost that had recently retracted to reveal the canine. The pup’s brain was found to be “surprisingly well preserved” and some researchers have suggested cloning the dog, an ancestor to a breed of canines that have long since gone extinct. Researcher Pavel Nikolsky told the Siberian Times the brain was 70-80% preserved. “Of course, it has dried out somewhat, but both the parencephalon, cerebellum and pituitary gland are visible. We can say that this is the first time we have obtained the brain of a Pleistocene canid.”

Ice Puppy
Ice Puppy

Referred to as the Tumat Puppy, named for the region in Russia near which it was found, the location is adjacent to what is believed to be an ancient human settlement overlooking the River Syalakh. It’s also believed the puppy could be related to the so-called Tumat Dog, a full-grown animal found under permafrost in 2011. That animal was found with bones, heart, lungs and stomach still preserved and intact. Researchers think both animals were killed during a landslide.

Cave lions existed!

Not only did ancient human ancestors have dogs running around, they had to worry about cave lions. Two baby lions were found in the Sakha Republic in Russia in June 2015 and are thought to be between 10,000 and 300,000 years old. This wasn’t the first time scientists had heard of cave lions—the first reference was found in 1810—but now the question is whether the cub-sicles are of the same species as the African lion we know today or if they’re more closely related to modern-day tigers.

Cave Lion. Image credit Vera Salnitskaya/Siberian Times
Cave Lion. Image credit Vera Salnitskaya/Siberian Times

In June 2015, when the cubs were found, an adult lion skeleton was flushed out of the permafrost by the Malyi Anyui River in Russia and testing determined that specimen was 61,000 years old. The cubs are better and more fully preserved than the adult lion, complete with fur around the skull of one cat. “As far as I know, there has never been a prehistoric cat found with this level of preservation, so this is truly an extraordinary find,” Julie Meachen, a Des Moines University field research told National Geographic. “I was a little in disbelief when I first saw it, but when it looked to be true I was just in awe.”

Squirrel!

It’s not just big predatory animals that took centuries-long naps under ice blankets. Under the permafrost was found a species of Arctic ground squirrel, relatives of which are still alive today. The squirrel found in Alaska is believed to be around 1.8 to 2.5 million years ago and first appeared in North America 10 million years ago before jumping from treetop to treetop (not really) into Eurasia. The descendants of these squirrels can be found in Siberia, the Canadian Eastern Arctic and, most notably, the southern Yukon Territory.

Arctic Ground Squirrel
Arctic Ground Squirrel

These squirrels are particularly adept at living in cold climates, hibernating in groups of 50 as far as 100 centimeters underground and dropping their body temperatures down to -2.9 degrees C. The area in which ancient Arctic squirrels have been found have also produced large seed preserves and plant samples, providing insight into the flora and fauna of ancient times and suggestions on what kinds of vegetation would’ve been common millions of years ago. One particularly well-preserved squirrel was donated to the Canadian Museum of Nature and, after being x-rayed, was found to be a complete mummified squirrel that had been frozen in hibernation position.

Giddy up! Ancient horse provides oldest DNA ever sequenced.

Back in 2003, researchers in the Yukon near the Alaskan border found the remains of a horse believed to be between 560,000 and 780,000 years old. Thanks to advancing science, it was determined that the genetic code contained in the animal’s remains is up to 4 million years ago, providing a common link to donkeys, horses and zebras twice as old as previously known.

10,000 Year old Horse - Still containing flesh and hair. - Credit Gleb Kraev Permafrost Researchers
10,000 Year old Horse – Still containing flesh and hair. – Credit Gleb Kraev Permafrost Researchers

“When we started the project, everyone—including us, to be honest—thought it was impossible,” said Dr. Ludovic Orlando of the University of Copenhagen. “And it was to some extent, with the methods available by then. So it’s clearly methodological advances that made this possible.” The importance of the discovery wasn’t only that our equine friends existed for longer than people thought; it’s that DNA can survive in a comprehensive and can be studied for millions of years. The proteins found in the animal’s bones were preserved thanks to the cold conditions in which they were interred for centuries, researchers said.

Ancient bacteria hold the secret to prehistoric life.

As the glaciers retract and offer up furry friends that have been long forgotten or wildly changed by evolution, Mother Nature’s thawing machine has also offered up microscopic time travelers in the form of prehistoric bacteria and organisms that can provide some insight into the pathogens of the past. “Masses of bacteria and other microbes—some of which the world hasn’t seen since the Middle Pleistocene, a previous period of climate change about 750,000 years ago—will make their way back into the environment.” Some believe the pathogenic population of these melting ice sheets could account for a biomass 1,000 times that of the human presence on the planet.

Ancient Virus
Ancient Virus

John Priscu, a professor at Montana State University, says the glacial retreat is “a way of recycling genomes. You put something on the surface of the ice and a million years later it comes back out.” Priscu should know—he’s spent nearly 30 years studying frozen microbes and pathogens in Antarctica, with some areas of bacterial growth dating back about 8 million years.

Adds Brent Christner of Louisiana State University, “We don’t really understand how an organism can sit around for 750,000 years in some sort of suspended animation like when Han Solo was put in carbonite,” but that’s exactly what scientists are finding and trying to learn from. And if life, even at the tiny microscopic level, can survive or come back from that extreme and harsh environment, it could suggest the existence of similar pockets of life on distant plants or moons.

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Amber Healy

Amber Healy has been writing, both personally and professionally, since she nagged her hometown paper to give her an internship in 1996. She's a big believer that the most fascinating stories are hidden under layers of seemingly boring drivel.