Colossal Biosciences has reported a milestone in its de-extinction effort: the company said it hatched live chicks from what it described as an artificial eggshell environment. According to the company, 26 baby chickens—ranging from a few days to several months old—were born after Colossal used a 3D-printed lattice structure that mimics an eggshell, with scientists watching embryo development and growth in real time.
Colossal said the work begins with eggs placed into the artificial system. The company poured fertilized eggs into the structure and added calcium, which the company said is normally absorbed from an eggshell, while using an incubator setting and imaging to track the embryos’ development.
Colossal CEO Ben Lamm framed the approach as a scalable technology for shaping bird development. In remarks carried in the Associated Press report, Lamm said, “We wanted to build something that nature has done a pretty good job of developing and make it better and scalable and even more efficient.”
The company’s broader plan targets extinct species through genetic engineering and surrogate breeding. Colossal has previously said it genetically engineered living animals to resemble extinct creatures, including mice with long hair like the woolly mammoth and wolf pups that take after dire wolves.
Outside experts acknowledged that the work could still contribute to avian reproductive research. Evolutionary biologist Vincent Lynch, of the University at Buffalo, said the technology could help with genetically modified birds but questioned the “artificial egg” label, saying, “They might be able to use this technology to help them make a genetically modified bird, but that’s just a genetically modified bird. It’s not a moa.”
Other scientists pointed to design limitations in what Colossal described as the eggshell system. Lynch said Colossal’s system did not include components he said are needed for a complete artificial egg, noting that Colossal’s membrane design addressed oxygen exchange but not additional egg functions. “That’s not an artificial egg because you’ve poured in all the other parts that make it an egg. It’s an artificial eggshell,” Lynch said.
Nicola Hemmings, a bird reproductive biologist at the University of Sheffield who was not part of Colossal’s team, said producing chicks from an artificial vessel is not entirely new. Hemmings said earlier research used cruder transparent eggshells, including approaches involving plastic films or sacks, and that those methods helped study chicken development.
Even so, Hemmings and others said the path to reviving an extinct bird remains long. Colossal has said its technology could eventually help build a New Zealand giant moa-like bird, including because moa eggs were described in the report as far larger than chicken eggs and would have posed laying challenges for modern birds. The report also said Colossal outlined near-term engineering goals for “surrogacy and birth,” rather than waiting for a giant moa birth attempt.
Bioethicist Arthur Caplan with New York University’s Grossman School of Medicine raised concerns about the next step after any engineered moa-like bird could be created—specifically, where such an animal would live. “The big challenge is, what environment is this animal going to live in?” Caplan said.
Hemmings said such de-extinction efforts may make more sense with currently endangered species. “Such de-extinction efforts may make more sense with currently endangered species, where scientists could preserve sperm and egg cells from living members to attempt to bring more back,” she said, adding: “My personal interests lie more in preserving what we’ve got than trying to bring back what is already gone.”
For Colossal, the immediate takeaway from the hatchlings is not just proof-of-concept, but a step toward addressing engineering challenges before any attempt at a moa-like resurrection. The report said scientists first would need to compare ancient moa DNA from well-preserved bones with genomes of living bird species and also would need a “bigger eggshell” than the artificial structure described for chickens.