‘Game of Thrones’ dire wolves, which went extinct over 10,000 years ago, are back. Here’s how

If you are a fan of the Stark family from George RR Martin’s Game of Thrones, there’s some good news for you. House Stark’s favourite pet — the dire wolf — has been brought back from extinction after more than 10,000 years.

That’s right. Scientists have crossed the first barrier of de-extinction by successfully bringing back a version of the dire wolf, 12,500 years after it last roamed the earth.

On Monday (April 7), scientists at Colossal Biosciences announced that they had created three dire wolf pups named Romulus, Remus and Khaleesi — two males that are six-months-old and one female that is two months old.

“I could not be more proud of the team,” said the CEO of Colossal Ben Lamm. “This massive milestone is the first of many coming examples demonstrating that our end-to-end de-extinction technology stack works.”

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Meet Romulus, Remus and Khaleesi

On Monday, Dallas-based biotech company Colossal Biosciences announced that it had brought three dire wolf pups to life — two six-month-old males named Romulus and Remus and a three-month-old female named Khaleesi. Romulus and Remus were born close together in October while Khaleesi was born in January.

SOUND ON. You’re hearing the first howl of a dire wolf in over 10,000 years. Meet Romulus and Remus—the world’s first de-extinct animals, born on October 1, 2024.

The dire wolf has been extinct for over 10,000 years. These two wolves were brought back from extinction using… pic.twitter.com/wY4rdOVFRH

— Colossal Biosciences® (@colossal) April 7, 2025

For now, the three wolf pups are living on a 2,000-acre site at an undisclosed location enclosed by a 10-foot-tall “zoo-grade” fencing, where they are monitored by security personnel, drones and live camera feeds. Colossal said the facility has been certified by the American Humane Society and registered with the US Department of Agriculture.

For those who are unaware, dire wolves, scientifically known as Aenocyon dirus, emerged during the Late Pleistocene, between 129,000 and 11,700 years ago. Considered a top predator, they lived throughout the Americas and were animals that looked like large wolves with white coats.

According to experts, they hunted horses, bison and possibly mammoths. However, as their prey species became extinct — in part because of human hunters — dire wolves also died out some 12,500 years ago.

Science to create a dire wolf

But just how did the scientists at Colossal Biosciences bring the dire wolves back to life?

Scientists at the company first extracted ancient DNA from two dire wolf fossils — a 13,000-year-old tooth from Sheridan Pit, Ohio, and a 72,000-year-old inner ear bone from American Falls, Idaho. The scientists extracted and sequenced the ancient DNA from the two fossils, assembling it into a genome that contained 500 times more data than the previous analysis.

The experts then compared those genomes to that of the gray wolf — the dire wolf’s closest living relative — and identified 20 differences in 14 genes that account for the dire wolf’s distinguishing characteristics, including its greater size, white coat, wider head, larger teeth, more powerful shoulders, more-muscular legs, and characteristic vocalisations, especially howling and whining.

The company then used the information to alter gray wolf cells, before cloning the most promising cell lines and transferring them into donor eggs, according to the news release. “Healthy developing embryos were then transferred into surrogates for interspecies gestation,” with three pregnancies that led to births of the first de-extinct species, Colossal revealed in its statement.

The company confirmed to CNN that it used domestic dogs — specifically large, mixed-breed hounds — as surrogates.

Dr Beth Shapiro, Colossal’s chief science officer, said to the New York Times, “We are creating these functional copies of something that used to be alive.”

Not exactly dire wolves, though

While Colossal has hailed this as a monumental moment in de-extinction, not all scientists agree that the three dire wolf pups are, in fact, actually dire wolves.

As Adam Boyko, a geneticist at Cornell University who was not involved in the project, said that while the work was exciting, the three pups weren’t truly resurrected dire wolves. In a New York Times report, he’s quoted as saying that the three aren’t being raised in dire-wolf packs. And they aren’t eating an ancient diet, so they are not acquiring their ancestors’ unique suite of intestinal microbes.

Even Vincent Lynch, a biologist from the University at Buffalo, noted that while it is possible to create organisms that resemble extinct species, true de-extinction — bringing back fully functional species — remains out of reach. “All you can do now is make something look superficially like something else — not fully revive extinct species,” Lynch stated.

But, Love Dalén, a professor in evolutionary genomics based at the Centre for Palaeogenetics at Stockholm University, and an adviser to Colossal, said, “It carries dire wolf genes, and these genes make it look more like a dire wolf than anything we’ve seen in the last 13,000 years. And that is very cool.”

Moreover, as Shapiro noted, “My colleagues in the field of taxonomy are going to be like, ‘It’s not a dire wolf’. But to me, if it looks like a dire wolf and it acts like a dire wolf, I’m going to call it a dire wolf.”

Future of de-extinction

While experts may continue to argue over whether the three new pups are truly dire wolves, Colossal has said that they are planning to use similar techniques to bring back the woolly mammoth in 2028.

They also want to use their technology to save endangered ones. For instance, they are trying to save the red wolf from dying out. For this, they have cloned four red wolves — a small but important step in fortifying the species as a whole.

However, for all their efforts, there is criticism of the money that is being spent on such programmes. Many believe that the huge amounts of cash that are being shelled out could be better used. “It’s better to prevent extinctions in the first place, rather than bring back bio-replicas whose ‘reintroduction’ may have a host of unintended consequences,” said Karl Flessa, a paleontologist at the University of Arizona.

For now, though, the dire wolf is back from the dead.

With inputs from agencies