DALLAS — Colossal Biosciences announced Tuesday that it had hatched more than two dozen healthy chicken chicks from 3D-printed artificial eggs developed at its Dallas facility. A company spokesperson said additional chicks would follow soon as part of its research toward resurrecting extinct birds such as the dodo and the giant moa.

The artificial eggs are made of 3D-printed plastic and engineered to replicate the functions of a natural egg. A honeycomb structure is designed to let oxygen in while keeping the contents from leaking out. The company is starting with chicken eggs to understand the functions that natural eggs need to support embryos before scaling the technology up for larger species.

"This is a chicken embryo. You can see the little chicken embryos moving around in there. It has eyes." said Trevor Snyder, a bioengineer at Colossal Biosciences, describing one of the developing embryos inside an artificial egg.

Colossal Biosciences plans to recreate the dodo and the giant moa using embryos made from gene-edited cells from the Nicobar pigeon for the dodo and possibly the emu for the moa. The genetically modified embryos would then be placed inside artificial eggs sized for each species. The giant moa was a flightless bird that looked like a giant ostrich when it roamed New Zealand hundreds of years ago.

The dodo's eggs were slightly larger than typical chicken eggs and those of the Nicobar pigeon, the dodo's closest living relative, Snyder said. The moa's eggs were about the size of a football, far larger than the eggs of the moa's closest living relatives such as the emu, he said.

The company has also said it brought the dire wolf back from extinction and hopes to resurrect other species, including the woolly mammoth and the Tasmanian tiger.

Neil Gostling, a paleobiologist at the University of Southampton, offered praise for the artificial egg work. "I'm genuinely blown away by it. This is brilliant. I just think it's fantastic," Gostling said.

Nic Rawlence, an associate professor of ancient ecology at the University of Otago, raised objections to the broader de-extinction effort. "There are a whole lot of ecological and ethical concerns around bringing back extinct species," Rawlence said. "They're not what I would actually call de-extinct species. They're poor facsimiles of extinct species. Extinction is still forever."