[URL unfurl="true"]https://www.cnn.com/2025/04/07/science/dire-wolf-de-extinction-cloning-colossal/index.html[/URL]

A species of wolf that died out some 12,500 years ago lives again as the “world’s first successfully de-extincted animal,” according to Dallas-based biotech company Colossal Biosciences.

Colossal scientists have created three dire wolf pups by using ancient DNA, cloning and gene-editing technology to alter the genes of a gray wolf, the prehistoric dire wolf’s closest living relative, the company announced Monday. The result is essentially a hybrid species similar in appearance to its extinct forerunner.

The dire wolf, Aenocyon dirus, which was the inspiration for the fearsome canine featured in the HBO TV series “Game of Thrones,” was a top predator that once roamed North America. (HBO shares parent company Warner Bros. Discovery with CNN.) Dire wolves were larger in size than gray wolves and “had a slightly wider head, light thick fur and stronger jaw,” the company said.

Colossal has been working toward resurrecting the mammoth, dodo and Tasmanian tiger since 2021, but the company had not previously publicized its work on dire wolves.

“This massive milestone is the first of many coming examples demonstrating that our end-to-end de-extinction technology stack works,” said Ben Lamm, Colossal’s cofounder and CEO, in a news release. “Our team took DNA from a 13,000 year old tooth and a 72,000 year old skull and made healthy dire wolf puppies.”

The three dire wolves are living on a 2,000-acre site at an undisclosed location enclosed by 10-foot-tall (3-meter-tall) “zoo-grade” fencing, where they are monitored by security personnel, drones and live camera feeds. Colossal said the facility had been certified by the American Humane Society and registered with the US Department of Agriculture.

Using ancient DNA extracted from two dire wolf fossils, Colossal’s scientists and collaborators said they were able to assemble two high-quality Aenocyon dirus genomes, or complete sets of genetic information.

The team compared the genomes with those of living canids such as wolves, jackals and foxes to identify the genetic variants for traits specific to dire wolves, such as white coats and longer, thick fur.

The company then used the information from the genetic analysis to alter gray wolf cells, making 20 edits in 14 genes 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.

Two male dire wolf pups were born on October 1, 2024, while a female pup was born on January 30, 2025, according to Colossal Biosciences.