Our Take
Colossal's artificial eggshell is a real engineering advance wrapped in false claims of novelty; shell-less incubation dates to 1998, and the actual win is the oxygen-permeable membrane, not the container.
Why it matters
The artificial egg is a credibility test for Colossal's extinct-species ambitions. If the company can't accurately describe what it has built, how much trust should investors place in its moa resurrection roadmap, which requires genetic engineering work that remains unsolved?
Do this week
Bio VCs and researchers: cross-check any Colossal capability claim against independent peer-reviewed sources before updating your thesis.
Colossal Printed Plastic Eggs and Hatched Chickens Inside Them
Colossal Biosciences announced today that it has grown chickens in 3D-printed artificial eggshells at its Dallas headquarters. The shells are oval-shaped printed lattices coated inside with a silicone-based membrane that permits oxygen exchange, mimicking a real eggshell's gas permeability. The company transferred embryos from freshly laid chicken eggs into the artificial shells, where they continued developing. A transparent window on top allowed researchers to observe the chicks. Colossal reports it hatched 26 chickens successfully before halting the experiment (per company statement).
The artificial eggshell is part of Colossal's stated plan to resurrect extinct bird species, particularly the giant moa, a 12-foot-tall flightless bird that lived in New Zealand until roughly 750 years ago. The company also announced a prototype scaled up dramatically for moa embryos, which it refers to internally as the "salad spinner" because of its size. Colossal has raised over $800 million (company-reported) since 2021 to pursue de-extinction and synthetic reproduction technologies.
The Innovation Is Real, But the Framing Overstates It
Colossal's YouTube announcement claimed the company had solved the "impossible question of which came first, the chicken or the egg" and created the "first-ever shell-less incubation system." Neither claim is accurate. Growing bird embryos in artificial containers dates to 1998, when Japanese researchers hatched quail using similar methods. Katsuya Obara, a researcher at the University of Tsukuba, hatched chickens from beneath transparent plastic film in 2024. Obara called Colossal's assertion "clearly an overstatement" and characterized the artificial eggshell as "essentially a modification of existing methods" (per MIT Tech Review reporting).
What may constitute genuine progress is the silicone-based membrane. Prior systems required scientists to manually supplement oxygen, which often led to hatch failures. If Colossal's membrane meaningfully reduces that intervention and improves survival rates, the company has a technical win. The company has not published independent benchmarks demonstrating hatch-rate improvements over prior systems, and no peer-reviewed data yet exists to confirm the claim.
The pattern mirrors Colossal's previous announcement that it had re-created the extinct dire wolf, a claim widely rejected by geneticists. The company appears to use press events and viral marketing to front-load public attention before the underlying science matures or undergoes scrutiny.
The Moa Roadmap Faces Unsolved Genetic and Embryological Hurdles
Colossal's longer-term vision requires solving problems the artificial eggshell alone cannot address. To create a moa, scientists must genetically edit an existing bird species (likely chickens, the only birds currently amenable to heritable genetic modification) and alter potentially thousands of DNA letters. Current techniques involve editing stem cells that produce sperm and eggs, then injecting those cells back into an embryo.
Even if successful, the size mismatch poses a crisis. A moa embryo is vastly larger than a chicken embryo and would exhaust the yolk of a standard chicken egg before reaching term. Pask, Colossal's chief biology officer, proposes using a fine needle to combine "50 yolks" into a larger mass, then transferring the moa embryo into the artificial egg environment to scale it further. This sequence remains untested and speculative.
Helen Sang, a professor emeritus at the Roslin Institute in the UK, expressed skepticism about whether a moa embryo could survive on chicken yolk at all, given evolutionary divergence. The artificial eggshell may prove useful for this work, but it is a enabler of an experiment, not a solution to the core genetic and developmental problems. Colossal's track record of overstating incremental progress should inform how practitioners and investors evaluate its timelines and feasibility claims going forward.