Colossal Biosciences says it has hatched 26 baby chickens inside a 3D-printed artificial eggshell system, a step it frames as groundwork for resurrecting New Zealand’s extinct South Island giant moa. Independent scientists applaud the engineering but argue the
On Tuesday, Colossal Biosciences released images and video of scientists lifting tiny chicks from a system designed to stand in for an eggshell—then the debate started almost immediately.
The company says 26 baby chickens. from a few days old to several months old. hatched inside a 3D-printed lattice structure that mimics an eggshell. with details built around an embryo’s oxygen supply and an environment meant to replicate parts of real egg development. Colossal’s CEO Ben Lamm framed the achievement as more than a novelty: he called it technology that could one day be scaled up to genetically tweak living birds to resemble New Zealand’s extinct South Island 12-foot giant moa.
In an interview response, 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.”
Colossal’s method, as described, involved pouring fertilized eggs into the artificial system and placing them in an incubator. The company also added calcium, normally absorbed from an eggshell. Scientists then imaged the embryos’ development and growth in real time.
The company says it designed an artificial eggshell with a membrane that lets in the right amount of oxygen, “just like a real egg.” But independent experts say the resemblance stops short of what an artificial egg would need in order to be considered a complete substitute.
Evolutionary biologist Vincent Lynch of the University at Buffalo. who is not part of the Colossal team. said the technology may help with genetic modification while still failing the core definition of de-extinction as many people imagine it. “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,” Lynch said.
Lynch also argued that what Colossal built is better described as an artificial eggshell rather than an artificial egg. “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,” he said.
According to the account of how the system works, some egg features were not included. While Colossal scientists designed for oxygen exchange and addressed calcium. other components—like temporary organs that form to nourish and stabilize the growing chick and remove waste—were not part of the design.
Nicola Hemmings. a researcher who studies bird reproductive biology at the University of Sheffield and is also not part of Colossal’s team. offered a warmer view of the engineering but still treated it as a different kind of breakthrough than a full artificial egg. “Producing a chick from an artificial vessel is not necessarily new,” Hemmings said. She added that earlier. cruder approaches—transparent eggshells made from plastic films or sacks—had already been used to study chicken development. The insights can be applied beyond birds, she said, to other mammals and even humans.
For Colossal, the larger goal is de-extinction. Lamm pointed to the moa’s scale—Colossal says moa eggs are 80 times the size of a chicken’s and would be difficult for any modern bird to lay. He also said Colossal does not intend to delay work until it is “ready to birth a giant moa. ” insisting the company wanted to start tackling the engineering challenges for surrogacy and birth now.
Colossal did not just propose a biological end point. It also framed the broader platform as a practical tool for bird conservation and reproduction. saying on social media that it could “help rescue fragile bird embryos. hatch birds that refuse to breed in captivity. and potentially revive species preserved as frozen cells and DNA.”.
The key question for many scientists is what comes after the first hatch. Bioethicist Arthur Caplan of New York University’s Grossman School of Medicine focused on survival in a world that may not match the past. “The big challenge is, what environment is this animal going to live in?” Caplan said.
Hemmings suggested de-extinction efforts may fit better where living species can provide genetic starting points that are already present in frozen form. “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.
Hemmings added a personal view that sharply contrasted with Colossal’s ambition. “My personal interests lie more in preserving what we’ve got than trying to bring back what is already gone,” she said.
Colossal also has a history that makes the stakes feel familiar—even to people skeptical of its ultimate aim. The company made headlines in 2021 by unveiling plans to revive the woolly mammoth and later the dodo bird. In 2024, it said it made a breakthrough in efforts to bring back the extinct Tasmanian tiger.
In a 2023 interview, CBS News correspondent Jonathan Vigliotti told Lamm, “I hear mammoth and dodo in the same sentence and, you know, it’s science fiction to me.” Lamm replied: “Yeah, I mean, it is, until it’s not.”
What happens next, experts say, depends on stepping from partial replication toward full biological reconstruction. Before Colossal attempts a moa resurrection using the artificial egg system. scientists say it needs to compare ancient DNA from well-preserved moa bones to genomes of living bird species. and it will also need a bigger eggshell.
Behind the spectacle of chicks hatching in a controlled setup is a deeper split: the technology looks impressive, but the path from engineered embryos to resurrected ecosystems is still long, uncertain, and—critics say—fundamentally mismatched to what counts as bringing something truly back.
Colossal Biosciences artificial eggshell de-extinction moa South Island giant moa biotech 3D-printed eggshell chick hatching bird reproductive biology bioethics Ben Lamm Vincent Lynch Nicola Hemmings Arthur Caplan