Scientists ‘de-extinct’ dire wolf that vanished over 12,000 years ago

A species of wolf that vanished around 12,500 years ago has been brought back to life as what a Dallas-based biotech firm calls the “world’s first successfully de-extincted animal.”

Colossal Biosciences announced on Monday that its scientists had created three dire wolf pups using ancient DNA, cloning, and gene-editing technology. This involved altering the genes of the gray wolf, the closest living relative of the prehistoric dire wolf, resulting in a hybrid species resembling its extinct ancestor.

The dire wolf, Aenocyon dirus, the inspiration for the fearsome canines in the HBO series “Game of Thrones,” was a top predator that once roamed North America. Dire wolves were larger than gray wolves, with a slightly wider head, light thick fur, and stronger jaws, according to the company.

While Colossal Biosciences has been working on resurrecting the woolly mammoth, dodo, and Tasmanian tiger since 2021, its work on dire wolves had not been previously publicised.

“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 co-founder 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 currently housed in a closely monitored and undisclosed 2,000-acre site enclosed by 10-foot-tall (3-meter-tall) “zoo-grade” fencing. The facility is monitored by security personnel, drones, and live camera feeds and has been certified by the American Humane Society and registered with the US Department of Agriculture, Colossal stated.

Dire wolf fossils and ancient DNA used

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

The team compared these genomes with those of living canids, including wolves, jackals, and foxes, to pinpoint the genetic variations responsible for traits specific to dire wolves, such as white coats and longer, thicker fur.

The company then used this genetic information to modify gray wolf cells, making 20 edits across 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,” resulting in three pregnancies and the births of the first de-extinct species, Colossal revealed. The company confirmed to CNN that domestic dogs — specifically large, mixed-breed hounds — were used as surrogates.

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

Colossal has raised at least $435 million since its founding in September 2021 by serial entrepreneur Ben Lamm and Harvard University geneticist George Church, when they first announced plans to resurrect the woolly mammoth. That project is taking longer than initially anticipated, with the company now aiming to introduce the first woolly mammoth calves in 2028.

Experts anticipate some debate within the scientific community regarding the precise number of genetic changes required for such pups to be definitively considered dire wolves.

The company hopes that the same technologies used to create the dire wolf can also directly aid endangered animals. Colossal announced on Monday that it has produced two litters of cloned red wolves, the most critically endangered wolf species, using a new, less invasive cloning method developed during the dire wolf research.