Dire Wolf, a species that disappeared over 12,500 years ago, has now returned, thanks to groundbreaking biotechnology developed by Dallas-based Colossal Biosciences.
Recently, Colossal’s scientists successfully engineered three dire wolf pups using a combination of ancient DNA, cloning, and advanced gene-editing techniques. By modifying the genes of a gray wolf — the closest living relative of the dire wolf — they created a hybrid that strongly resembles the extinct predator.
The dire wolf (Aenocyon dirus), which inspired the massive wolves in HBO’s Game of Thrones, once roamed North America as a dominant predator. Compared to the modern gray wolf, dire wolves were larger, had broader heads, thicker pale fur, and more powerful jaws.
Since 2021, Colossal has worked toward reviving species such as the woolly mammoth, dodo, and Tasmanian tiger. However, this breakthrough marks the first time the company has publicly shared its efforts to resurrect the dire wolf.
“This achievement proves that our de-extinction platform is effective,” said Colossal cofounder and CEO Ben Lamm. “We extracted DNA from a 13,000-year-old tooth and a 72,000-year-old skull, leading to the birth of healthy dire wolf pups.”
Currently, the pups live on a secured 2,000-acre site enclosed with 10-foot-tall zoo-grade fencing. Moreover, the facility is monitored by security staff, drones, and live camera feeds. Colossal emphasized that the location is certified by the American Humane Society and registered with the USDA.
Using Fossils to Rebuild DNA
To begin with, Colossal’s scientists and their collaborators extracted ancient DNA from dire wolf fossils. They then built two high-quality Aenocyon dirus genomes and compared them with those of modern canids like wolves, jackals, and foxes. This step helped identify the specific genes responsible for dire wolf traits, including thick fur and white coats.
After completing the analysis, the team used CRISPR technology to edit the DNA of gray wolf cells. In total, they made 20 edits across 14 genes. Subsequently, they cloned the best-performing cell lines and transferred them into donor eggs.
Next, they implanted the developing embryos into surrogate mothers. All three pregnancies were successful. As a result, two male pups were born on October 1, 2024, while one female pup was born on January 30, 2025. Colossal confirmed that large, mixed-breed domestic dogs served as the surrogates.
Gene Editing Brings Prehistoric Predators to Life
To achieve this feat, Colossal utilized CRISPR to replace gray wolf gene sequences with dire wolf traits. According to Love Dalén, an evolutionary genomics professor at Stockholm University and adviser to Colossal, this process produced animals that visibly resemble dire wolves more than any species alive today.
“There’s no doubt this is 99.9% gray wolf genetically,” Dalén noted. “Nevertheless, the inserted genes give it a dire wolf appearance. That’s incredibly exciting.”
Although Dalén helped analyze the dire wolf genome, he was not directly involved in the cloning process. Still, he called the development a major leap forward in de-extinction science. “The pups reflect the dire wolf’s phenotype. Based on genetic data, they likely mirror the ancient species,” he said.
Ethical Impact and Future Potential
Since its launch, Colossal has raised at least $435 million. The company, co-founded by Lamm and Harvard geneticist George Church, initially announced plans to bring back the woolly mammoth. While that project is still in progress, Colossal now expects the first mammoth calves by 2028.
In addition to its de-extinction goals, the company also aims to support endangered species. Recently, Colossal produced two litters of cloned red wolves — the most critically endangered wolf species—using new, less invasive methods developed during the dire wolf research.
Nevertheless, not everyone supports de-extinction. Critics argue that such efforts divert funding from existing conservation programs. Furthermore, some worry about the welfare of animals used as surrogates. However, others see promise.
For instance, Christopher Preston, an environmental philosophy professor at the University of Montana, praised Colossal’s ethical considerations. He pointed to the spacious habitat and American Humane Society endorsement as positive signs.
Despite the success, Preston questioned whether dire wolves could ever thrive in modern ecosystems. “Right now, we’re struggling to protect gray wolves in places like Montana,” he said. “It’s difficult to imagine dire wolves being released and fulfilling a natural ecological role.”
