De-extinction firm Colossal Biosciences says it has developed an artificial eggshell and related incubation approach as an early step toward reviving New Zealand’s extinct giant moa. The moa was flightless, stood more than 3 metres tall, weighed over 200 kilograms, and laid eggs larger than those of any living bird. Colossal reports that it has created a “shell-less” culture system and that it has been successfully used in incubating chickens, which the company says supports the prospect of scaling the method for much larger birds in future research. Colossal’s chief biology officer, Andrew Pask, says the system is designed to be fully scalable and biologically accurate. Other scientists express scepticism about whether the technique—and de-extinction efforts more broadly—can be applied to a moa-sized animal, given the complexity of recreating an extinct species beyond egg and embryo culture alone. Forbes adds that the company presents the technology as broadly useful for science and other applications, while The Guardian focuses on the implications for resurrecting the moa and highlights ongoing debate among researchers.