In a breakthrough that blurs the line between science fiction and reality, three white-furred pups representing an iconic Ice Age species are now thriving on a secure expansive ecological preserve. Romulus, Remus, and Khaleesi aren’t ordinary wolves—they’re dire wolves (Aenocyon dirus), apex predators that vanished from Earth approximately 12,000 years ago.
Dallas-based biotechnology company Colossal Biosciences announced on April 7, 2025, that it has successfully produced these living dire wolf pups, marking what many scientists are calling the first true de-extinction event in history.
The New Arrivals
The two males, Romulus and Remus (named after the mythical founders of Rome), were born in October 2024, while the female, Khaleesi (a nod to the “Game of Thrones” character), arrived in January 2025. Now about six months and three months old respectively, these pups represent a species that disappeared at the end of the last Ice Age.
Physically, they already exhibit the classic features that defined their ancient ancestors. Their thick white fur, broad heads, and hefty builds distinguish them from modern wolves. At just six months old, Romulus and Remus already weigh approximately 80 pounds—considerably larger than gray wolf pups of the same age.
Their behavior is equally telling. Unlike domestic puppies that seek human attention, these dire wolf pups maintain their distance from people. They flinch or retreat even from familiar caretakers, demonstrating the wild lupine instincts encoded in their reconstructed genome.
“These are not dogs, or even modern-day wolves. They’re dire wolf pups, back from extinction after some 12,000 years,” noted Colossal’s announcement.
A Safe Haven
The dire wolf pups currently reside on a 2,000+ acre secure expansive ecological preserve secure expansive ecological preserve under continuous care and monitoring. The facility—certified by the American Humane Society—includes naturalistic habitats designed to mimic the environments where dire wolves once roamed and on-site veterinary support to ensure the animals’ well-being.
Colossal employs a full-time animal care team that provides round-the-clock observation. The company has also established an interactive “dire wolf development tracker” to share the pups’ progress with the scientific community and the public, demonstrating a commitment to transparency.
Robin Ganzert, Ph.D., CEO of the American Humane Society, praised Colossal’s approach to animal welfare: “Colossal has achieved American Humane Certification for their extensive animal welfare program and is a shining example of excellence in humane care. The technology they are pursuing may be the key to reversing the sixth mass extinction and making extinction events a thing of the past.”
The Science Behind the Resurrection
Bringing back the dire wolf required an unprecedented fusion of cutting-edge genetic and reproductive technologies. The process began with ancient DNA extracted from dire wolf fossils—specifically, a 13,000-year-old tooth and a 72,000-year-old skull.
From these remains, Colossal’s scientists sequenced and reconstructed the dire wolf genome, creating a genetic blueprint of the extinct species. Next, they identified 14 important genes with 20 distinct genetic variants that give dire wolves their characteristic features, including their larger size, more muscular build, wider skull, and distinctive coat color.
Using CRISPR gene-editing technology, the team modified living cells from modern gray wolves to carry these dire wolf genetic traits. Rather than invasively harvesting tissue, scientists drew blood from living gray wolves and isolated endothelial progenitor cells (EPCs).
The scientists then applied CRISPR editing to these cells, precisely rewriting the DNA at the 14 target genes to install the 20 dire wolf variants. This process required extraordinary care—for example, the team engineered around a potential issue where some coat-color gene variants might cause deafness by adding compensatory genetic changes.
Once the cells were genetically modified, Colossal used cloning techniques to turn them into embryos. Scientists removed the nucleus from dog egg cells and replaced it with the nucleus of an edited cell—essentially creating embryos that carried the dire wolf genetic profile.
These viable embryos were then implanted into surrogate mother dogs (hound mixes) for gestation. After approximately 65 days, the pups were delivered via scheduled cesarean sections. Remarkably, Colossal reported no miscarriages or stillbirths during these trials, indicating an exceptional success rate.
This achievement set a scientific record: 20 precise genetic edits were made to create the dire wolf—the highest number of deliberate genome edits in any animal to date. By comparison, Colossal’s previous feat, the “woolly mouse” with mammoth genes, had only 8 edits.
Conservation Applications
Beyond the headline-grabbing resurrection of an Ice Age predator, Colossal emphasizes that de-extinction science directly benefits endangered species conservation. Alongside the dire wolf births, the company announced it had successfully cloned two litters of critically endangered red wolves (Canis rufus), producing four healthy pups using the same “non-invasive blood cloning” approach developed for the dire wolf work.
With only a handful of red wolves remaining in the wild, this cloning breakthrough could significantly bolster recovery efforts for one of North America’s most endangered mammals.
“The same technologies that created the dire wolf can directly help save a variety of other endangered animals as well. This is an extraordinary technological leap for both science and conservation,” stated Dr. Christopher Mason, a Colossal scientific advisor.
Beyond complete cloning, the gene-editing technologies refined through the dire wolf project are being applied to other conservation challenges. Colossal scientists are working with the pink pigeon, a bird species suffering from severe genetic bottlenecks, to introduce greater genetic diversity into embryos through edited primordial germ cells.
Expert Reactions
The scientific community has largely celebrated this achievement as a landmark in biotechnology and conservation. Dr. George Church, Harvard geneticist and Colossal co-founder, called it proof that their “end-to-end de-extinction technology stack works.” He noted that delivering 20 precise edits in a healthy animal is unprecedented, calling it “the largest number of precise genomic edits in a vertebrate so far—a capability that is growing exponentially.”
Dr. Beth Shapiro, Colossal’s chief science officer and a leading ancient DNA expert, celebrated the project as “a new standard for paleogenome reconstruction.” She explained that powerful computational tools and DNA recovery techniques allowed the team to link extinct DNA variants to key dire wolf traits.
Even cultural figures have recognized the significance of this achievement. George R.R. Martin, author of the “Game of Thrones” series that popularized dire wolves in contemporary culture, remarked: “I get the luxury to write about magic, but Ben and Colossal have created magic by bringing these majestic beasts back to our world.”
Mark Fox, Tribal Chairman of the MHA Nation, reflected on the spiritual significance, noting that the dire wolf’s birth “symbolizes a reawakening—a return of an ancient spirit to the world,” underscoring humanity’s responsibility to protect the balance of life.
What’s Next for Romulus, Remus, and Khaleesi?
As the dire wolf pups continue to grow and develop, Colossal’s team is carefully monitoring their health and behavior. The company reports that the pups are meeting all developmental milestones and thriving in their controlled environment.
Colossal has not yet announced long-term plans for the dire wolves, though the focus remains on scientific study and potential ecological applications rather than public exhibition. The company’s transparent approach suggests that the scientific and conservation communities will continue to receive updates as these pioneering animals mature.
Meanwhile, the successful resurrection of the dire wolf validates Colossal’s de-extinction platform and suggests that more ambitious targets are within reach. The company is applying similar methods to its other headline projects, aiming to reintroduce the woolly mammoth by 2028 and to revive the thylacine (Tasmanian tiger) and dodo thereafter.
As Colossal CEO Ben Lamm stated: “This massive milestone is the first of many… Today, our team gets to unveil some of the magic they are working on and its broader impact on conservation.”
For now, Romulus, Remus, and Khaleesi represent living proof that extinction need not be forever—a powerful message of hope in an era of accelerating biodiversity loss.
