A de-extinction company is raising fresh scientific questions after announcing that it hatched live chicks using an artificial system designed to mimic aspects of an eggshell. Colossal Biosciences said Tuesday that 26 baby chickens—ranging from a few days old to several months old—were born from a 3D-printed lattice structure, a development it framed as progress toward its broader effort to resurrect lost species.
Colossal’s earlier work, described by the company as genetic engineering designed to make living animals resemble extinct creatures, included mice engineered with long hair like the woolly mammoth and wolf pups meant to take after dire wolves. In the new report, Colossal positioned its artificial environment as a technical stepping stone for more ambitious targets, including New Zealand’s South Island giant moa, an extinct bird Colossal said would present special challenges because moa eggs were about 80 times the size of a chicken’s egg and would be difficult for a modern bird to lay.
Ben Lamm, the company’s CEO, described the technology as something that can be made “better and scalable and even more efficient,” saying in remarks reported by the Associated Press that the company wanted to build on what nature already does well. Lamm told AP the company’s goal was to create an artificial system that could eventually support genetically modified birds designed to resemble the moa.
According to AP, Colossal scientists said they created the conditions for hatching by pouring fertilized eggs into the artificial system, placing the structure in an incubator, adding calcium that is normally absorbed from the eggshell, and imaging embryos as they developed. Colossal said the engineered eggshell design included a membrane intended to allow the right amount of oxygen to enter, similar to what happens in a real egg.
However, independent scientists who reviewed the approach said the “artificial egg” label does not fully match what the company built. Evolutionary biologist Vincent Lynch, with the University at Buffalo, said the system lacks components that make something an artificial egg, calling it “an artificial eggshell” rather than a complete artificial egg, and he argued that reviving extinct beasts like the moa is likely impossible in the form Colossal is pursuing.
Lynch and other experts said that while prior work has produced cruder substitutes—such as transparent shells or artificial barriers that supported chick development—Colossal’s advance still does not incorporate parts of a typical egg that help nourish and stabilize the embryo. AP reported that scientists said temporary organs that form during normal egg development to nourish the chick and remove waste were not included in Colossal’s system.
Nicola Hemmings, a researcher at the University of Sheffield who studies bird reproductive biology and said she is not part of Colossal, said producing a chick from an artificial vessel is not necessarily new, while emphasizing that the broader de-extinction path may face major scientific hurdles. Hemmings said scientists would need to compare ancient DNA from well-preserved moa bones with genomes of living bird species and would also likely need a bigger eggshell before a moa attempt could be practical.
Colossal’s timeline, as described by Lamm, starts engineering tasks for surrogacy and birth before the company is ready to attempt a giant moa “birth.” Lamm said the company did not want to wait “till we were ready to birth a giant moa,” framing early work on the engineering challenges as a way to build capabilities while de-extinction planning proceeds.
Even if Colossal were able to create a tall bird similar to the moa, additional challenges could remain after any embryo-development breakthrough. Arthur Caplan, a bioethicist with New York University’s Grossman School of Medicine, said the “big challenge” would be determining what environment such an animal could live in, given that a recreated species would face a landscape that does not match the one that existed when the moa was alive.
Hemmings added that de-extinction efforts may make more sense for species that are currently endangered, where scientists can preserve sperm and egg cells from living members to attempt to bring them back. She said her personal focus is more on preserving what is already alive than trying to recreate what is already gone.