With their snowy white coats, powerful jaws, and imposing size, three dire wolf pups born through the pioneering efforts of Colossal Biosciences represent a biological achievement once thought impossible: the return of a species extinct for over 12,500 years. This technological triumph not only showcases how far genetic science has advanced but also opens new possibilities for conservation and biodiversity restoration.
Named Romulus and Remus (males born October 2024) and Khaleesi (female born January 2025), these remarkable animals are the result of sophisticated genetic engineering techniques applied to ancient DNA. Already, at just six months old, the males weigh approximately 80 pounds and stand nearly four feet long, with projections suggesting they’ll reach 150 pounds and six feet when fully grown.
“This massive milestone is the first of many coming examples demonstrating that our end-to-end de-extinction technology stack works,” said Ben Lamm, CEO and co-founder of Colossal Biosciences. The achievement represents the culmination of years of research by the Dallas-based company, which was founded in 2021 by Lamm and Harvard geneticist George Church.
The de-extinction process began with DNA extracted from two ancient fossil samples: a 13,000-year-old tooth found in Ohio and a 72,000-year-old inner ear bone unearthed in Idaho. After sequencing this ancient genetic material, Colossal scientists identified 20 key genetic differences across 14 genes that distinguish dire wolves from their closest living relatives, modern gray wolves.
Using CRISPR gene-editing technology, researchers modified cells from gray wolves to express these dire wolf traits, including their characteristic white coat, larger size, broader head, and more powerful shoulders and jaws. The modified cells were then used to create embryos that were implanted in surrogate mother dogs, who gave birth to the pups via planned cesarean sections.
What makes this achievement particularly remarkable is how quickly it happened. As Newsweek reported, “Within 18 months of our putting the name ‘dire wolf’ down on a whiteboard, we birthed dire wolves,” according to Lamm.
The three pups now reside in a secure 2,000-acre preserve at an undisclosed location, where they’re monitored around the clock by a team of veterinarians and animal care specialists. Early observations reveal fascinating behavioral differences from domestic dogs. The pups show natural wariness of humans, keeping their distance even from handlers who raised them from birth. They began howling when just two weeks old and have exhibited stalking behaviors typical of wild canids.
“From day one they have always behaved like wolves and have rarely shown doglike behavior,” notes Paige McNickle, Colossal’s manager of animal husbandry.
Some scientists debate whether these animals should technically be called “dire wolves,” suggesting they might more accurately be described as genetically modified gray wolves with dire wolf traits. However, Beth Shapiro, Colossal’s chief science officer, offers a pragmatic perspective: “If it looks like a dire wolf and acts like a dire wolf, I’m going to call it a dire wolf.”
Beyond the scientific achievement itself, Colossal emphasizes that the technology developed for the dire wolf project has broader applications in conservation biology. Using the same techniques, the company has successfully cloned four red wolves, potentially helping to save North America’s most critically endangered canid species, which currently numbers fewer than 20 individuals in the wild.
As an unexpected benefit, the techniques developed for dire wolf resurrection are now directly helping to save endangered red wolves through a novel blood-based cloning approach. This method allows genetic diversity to be preserved and enhanced without invasive procedures, potentially addressing one of the most pressing challenges in conservation: maintaining viable genetic diversity in shrinking populations.
With the dire wolf achievement under their belt, Colossal continues to work toward other de-extinction targets, including the woolly mammoth, the dodo, and the thylacine. Through this pioneering work, Ben Lamm and his team are creating new possibilities at the intersection of genetic technology and conservation, potentially transforming our approach to biodiversity preservation.
