For First Time in 13K Years, the Dire Wolf Roams the Earth

Colossal Biosciences says it's achieved its first successful case of de-extinction in reviving the dire wolf, a top predator that roamed North America before going extinct about 13,000 years ago and later finding fame on Game of Thrones. Researchers at Colossal, which is working to revive various species from the woolly mammoth to the dodo bird, reconstructed the dire wolf's genome with DNA taken from a 13,000-year-old tooth and 72,000-year-old skull, keying in on versions of genes not found in any other wolf relatives, per Live Science. They then made 20 edits in 14 genes of gray wolves, the closest living cousins to dire wolves, to give the animals features of their extinct cousins, including a wider head, larger teeth, and thick, pale coats.

Embryos were then created from the edited cells and implanted in surrogate dog mothers. Three healthy wolves resulted, according to Colossal. The team is calling it the "world's first de-extinction," though it comes more than 20 years after scientists revived the Pyrenean ibex, an extinct wild goat species, per Live Science. The goat lived only a few minutes. Colossal's two male wolves, dubbed Romulus and Remus, are now six months old, while a female named Khaleesi is two months old, per the New York Times. They're not exactly dire wolves, but "essentially a hybrid species similar in appearance to its extinct forerunner," per CNN.

"Across the genome, this is 99.9% gray wolf," Colossal adviser Love Dalén, a professor in evolutionary genomics at Stockholm University, tells CNN. But "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." Housed at a private 2,000-acre facility somewhere in the northern US, the wolves are "snowy white" and "reminiscent of Ghost," Jon Snow's dire wolf in Game of Thrones, Live Science reports. Footage shows Romulus and Remus taking their first steps, howling, and playing in the snow. In a statement, Colossal says it also produced four cloned red wolves, a critically endangered species with fewer than two dozen remaining in the wild, per ABC News. (Last month, the company revealed a "woolly mouse.")