The dire wolf, a species that went extinct approximately 12,500 years ago but gained fame through its portrayal in the *Game of Thrones* series, has reportedly been resurrected by Texas-based biotech firm, Colossal Biosciences.
Colossal asserts that the dire wolf is now the “world’s first successfully de-extinct animal”. On April 7, 2025, the company announced the birth of three pups—named Romulus, Remus, and Khaleesi.
However, genetic analyses indicate these wolves possess DNA closely resembling that of the grey wolf, prompting questions about the veracity of Colossal’s claims.
What is a Dire Wolf?
The dire wolf, scientifically known as *Aenocyon dirus*, is recognized as one of the most powerful carnivores from prehistoric North America. Fossils suggest that their robust body structure was built for strength rather than speed, as they were muscular, with a hefty build surpassing that of modern wolves.
Despite their size, dire wolves were adept at navigating diverse environments and proficient in hunting large prey during the Ice Age, such as bison and possibly even mammoths. Their extinction coincided with changes in prey availability and human hunting practices, leading to the rise of the grey wolf in North America.
SOUND ON. You’re hearing the first howl of a dire wolf in over 10,000 years. Meet Romulus and Remus—the world’s first de-extinct animals, born on October 1, 2024.
— Colossal Biosciences® (@colossal) April 7, 2025
Author and investor George R.R. Martin remarked, “Many people view dire wolves as mythical creatures… they have a rich history of contributing to the American ecosystem.” He added, “They created magic by bringing these majestic beasts back to our world.”
Distinctions from Common Wolves
Colossal describes dire wolves as having a bulkier physique compared to grey wolves, featuring thicker legs and broader heads. Genetically, however, dire wolves are not direct ancestors of grey wolves; studies show they diverged millions of years ago.
Methods of Resurrection
The restoration process involved extracting ancient DNA from dire wolf fossils—specifically a 13,000-year-old tooth and a 72,000-year-old bone. Researchers pinpointed 20 unique genetic factors distinguishing dire wolves from grey wolves and utilized CRISPR technology to integrate these genetic traits into grey wolf cells. The modified cells were then implanted into domestic dog surrogates, leading to the birth of the current trio of pups.
The New Pups: Romulus, Remus, and Khaleesi
Romulus and Remus, born on October 1, 2024, are nearly four feet long and weigh around 80 pounds, expected to mature to six feet and 150 pounds. Their sibling, Khaleesi, born later, exhibits similar growth traits and physical features.
Upon the birth of the first pup, Chief Animal Officer Matt James described the experience, saying, “Good lord, this thing is huge.”
Controversies Surrounding De-Extinction
Despite Colossal’s claims, experts argue these creatures are genetically modified versions of grey wolves rather than true dire wolves. Ben Lamm, Colossal’s CEO, stated, “We call them dire wolves,” while others pointed out the significant genetic overlap with grey wolves.
Eminent evolutionary genomics professor Love Dalen stated, “There’s no secret that across the genome, this is 99.9 percent grey wolf”. He emphasized the ongoing philosophical debate over how many genetic changes are required for a species to be considered resurrected.
We’re Colossal Biosciences, responsible for bringing back the first animals from extinction… watch these pups grow on our YouTube channel.
— Colossal Biosciences® (@colossal) April 7, 2025
Motivations Behind the Project
Colossal intends to utilize advances in genetic engineering to aid conservation, especially for species with diminishing genetic diversity. Andrew Pask, a member of Colossal’s advisory board, stated, “This project demonstrates the awesome potential for genetic engineering to recreate lost diversity and stabilize ecosystems.” However, some conservationists remain skeptical, viewing this as a distraction from pressing conservation needs.
Colossal has received substantial investment, totaling $435 million and increasing its valuation to $10.2 billion.
Future Endeavors
Moving forward, Colossal aims to monitor the pups’ health and behavioral development, with plans on exploring further possibilities for the de-extinction of additional species, including the woolly mammoth.
While the resurrection of the dire wolf presents notable advancements in genetic engineering, questions about ethical stewardship and conservation remain relevant for the scientific community.
