The researchers focused on two genes that help control the development of the middle of the face. The activity of these genes differed from that of reptiles early in embryonic development. They developed molecules that suppressed the activity of the proteins that these genes produced, which led to the embryos developing snouts that resembled their ancestral dinosaur state.

The researchers stressed that they are not yet capable of genetically modifying chickens to make them resemble their dinosaur ancestors. “We’re not altering the genes themselves yet — we’re altering the proteins that the genes produce,” Bhullar said.

One intriguing implication of this research is that relatively simple genetic changes could have caused this anatomical change in the ancestors of birds, and that one might expect to see abrupt changes in anatomy in the fossil record. Bhullar said that such changes are seen in an extinct near relative of modern birds known as Hesperornis.